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CHU, K. K., P. C. CHAO i J. A. WINDYKA. "STABLE HIGH POWER GaN-ON-GaN HEMT". International Journal of High Speed Electronics and Systems 14, nr 03 (wrzesień 2004): 738–44. http://dx.doi.org/10.1142/s0129156404002764.
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High power AlGaN/GaN HEMTs on free-standing GaN substrates with excellent stability have been demonstrated for the first time. When operated at a drain bias of 50V, devices without a field plate showed a record CW output power density of 10.0W/mm at 10GHz with an associated power-added efficiency of 45%. The efficiency reaches a maximum of 58% with an output power density of 5.5W/mm under a drain bias of 25V at 10GHz. Long-term stability of device RF operation was also examined. Under ambient conditions, devices biased at 25V and driven at 3dB gain compression remained stable at least up to 1,000 hours, degrading only by 0.35dB in output power. Such results clearly demonstrate the feasibility of GaN - on - GaN HEMT as an alternative device technology to the GaN - on - SiC HEMT in supporting reliable, high performance microwave power applications.
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Nela, Luca, Ming Xiao, Yuhao Zhang i Elison Matioli. "A perspective on multi-channel technology for the next-generation of GaN power devices". Applied Physics Letters 120, nr 19 (9.05.2022): 190501. http://dx.doi.org/10.1063/5.0086978.
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The outstanding properties of Gallium Nitride (GaN) have enabled considerable improvements in the performance of power devices compared to traditional silicon technology, resulting in more efficient and highly compact power converters. GaN power technology has rapidly developed and is expected to gain a significant market share in an increasing number of applications in the coming years. However, despite the great progress, the performance of current GaN devices is still far from what the GaN material could potentially offer, and a significant reduction of the device on-resistance for a certain blocking voltage is needed. Conventional GaN high-electron-mobility-transistors are based on a single two-dimensional electron gas (2DEG) channel, whose trade-off between electron mobility and carrier density limits the minimum achievable sheet resistance. To overcome such limitations, GaN power devices including multiple, vertically stacked 2DEG channels have recently been proposed, showing much-reduced resistances and excellent voltage blocking capabilities for a wide range of voltage classes from 1 to 10 kV. Such devices resulted in unprecedented high-power figures of merit and exceeded the SiC material limit, unveiling the full potential of lateral GaN power devices. This Letter reviews the recent progress of GaN multi-channel power devices and explores the promising perspective of the multi-channel platform for future power devices.
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Martín-Guerrero, Teresa M., Damien Ducatteau, Carlos Camacho-Peñalosa i Christophe Gaquière. "GaN devices for power amplifier design". International Journal of Microwave and Wireless Technologies 1, nr 2 (kwiecień 2009): 137–43. http://dx.doi.org/10.1017/s1759078709000178.
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This paper describes some aspects of the fabrication and modeling of a GaN device to be employed in a power amplifier covering one WiMAX frequency band. The work has been carried out in the frame of the TARGET's NoE work package WiSELPAS. Details concerning the AlGaN/GaN device technology and the performed linear and nonlinear measurements are provided. Since these new devices require specific nonlinear models, a procedure for selecting an appropriate simplified nonlinear model and for extracting its parameters is discussed and evaluated. The developed nonlinear model has been experimentally tested under linear and nonlinear conditions. The agreement between experimental and model-predicted performance suggests that the described model could be useful in a preliminary power amplifier design.
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Di, Kuo, i Bingcheng Lu. "Gallium Nitride Power Devices in Magnetically Coupled Resonant Wireless Power Transfer Systems". Journal of Physics: Conference Series 2463, nr 1 (1.03.2023): 012007. http://dx.doi.org/10.1088/1742-6596/2463/1/012007.
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Abstract The main function of power devices is to convert electrical energy through high-speed switching, such as AC/DC, high and low voltage conversion, etc. Therefore, the performance of the device directly affects the performance of the power electronic device, thereby further affecting the conversion efficiency of electrical energy. The arrival of the 5G era has greatly increased the demand for gallium nitride (GaN). The development of the wireless communication market has made GaN play a key role in many aspects of human activities. The main aim of this article is to research the application of GaN power devices in magnetically coupled resonant wireless power transfer (WPT) systems. This paper first introduces the related concepts of GaN power devices, magnetic coupling resonance and WPT, and analyzes the construction of magnetic coupling resonance WPT system in detail. Secondly, the energy transmission structure is analyzed, the system is designed and the system loss is calculated and analyzed. The system loss experiment shows that by using the output capacitor of the GaN device, the dead time is optimized, the conduction loss of the switch tube is reduced, the efficiency of the converter device is improved, and the practical application of the GaN device is provided.
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Roberts, J., A. Mizan i L. Yushyna. "Optimized High Power GaN Transistors". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2015, HiTEN (1.01.2015): 000195–99. http://dx.doi.org/10.4071/hiten-session6-paper6_1.
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GaN transistors intended for use at 600–900 V and that are capable of providing of 30–100 A are being introduced this year. These devices have a substantially better switching Figure-of-Merit (FOM) than silicon power switches. Rapid market acceptance is expected leading to compound annual growth rates of 85 %. However these devices present new packaging challenges. Their high speed combined with the very high current being switched demands that very low inductance packaging must be combined with highly controlled drive circuitry. While convention, and the usually vertical power device die structure, has largely determined power transistor package formats in the past, the lateral nature of the today GaN devices requires the use of new package types. The new packages have to operate at high temperatures while providing effective heat removal, low inductance, and low series resistance. Because GaN devices are lateral they require the package metal tracks to be integrated within the on-chip tracks to carry the current away from the thin on-chip metal tracks. The new GaN devices are available in two formats: one for use in embedded modular assemblies and the other for use mounted upon conventional circuit board systems. The package intended for discrete printed circuit board (PCB) assemblies has a top side cooling option that simplifies the thermal interface to the heat sink. The paper describes the die layout including the added copper tracks. The corresponding package elements that interface directly with the surface of the die play a vital role in terms of the current handling. They also provide the interface to the external busbars that allow the package to be mounted within, or on PCB. The assembly has been subject to extensive thermal analysis and the performance of a 30 A, 650 V transistor is described.
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Zhong, Min, Ying Xi Niu, Hai Ying Cheng, Chen Xi Yan, Zhi Yuan Liu i Dong Bo Song. "Advances for Enhanced GaN-Based HEMT Devices with p-GaN Gate". Materials Science Forum 1014 (listopad 2020): 75–85. http://dx.doi.org/10.4028/www.scientific.net/msf.1014.75.
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With the development of high-voltage switches and high-speed RF circuits, the enhancement mode(E-mode) AlGaN/GaN HEMTs have become a hot topic in those fields. The E-mode GaN-based HEMTs have channel current at the positive gate voltage, greatly expanding the device in low power digital circuit applications. The main methods to realize E-mode AlGaN/GaN HEMT power devices are p-GaN gate technology, recessed gate structure, fluoride ion implantation technology and Cascode structure (Cascode). In this paper, the advantage and main realizable methods of E-mode AlGaN/GaN HEMT are briefly described. The research status and problems of E-mode AlGaN/GaN HEMT devices fabricated by p-GaN gate technology are summarized. The advances of p-GaN gate technology, and focuses on how these research results can improve the power characteristics and reliability of E-mode AlGaN/GaN HEMT by optimizing device structure and improving process technology, are discussed.
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Chowdhury, Sauvik, Zachary Stum, Zhong Da Li, Katsunori Ueno i T. Paul Chow. "Comparison of 600V Si, SiC and GaN Power Devices". Materials Science Forum 778-780 (luty 2014): 971–74. http://dx.doi.org/10.4028/www.scientific.net/msf.778-780.971.
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In this paper the DC and switching performance of 600V Si, SiC and GaN power devices using device simulation. The devices compared are Si superjunction MOSFET, Si field stop IGBT, SiC UMOSFET and GaN HEMT.
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Zhang, Yuhao, Ruizhe Zhang, Qihao Song, Qiang Li i J. Liu. "(Invited) Breakthrough Avalanche and Short Circuit Robustness in Vertical GaN Power Devices". ECS Meeting Abstracts MA2022-01, nr 31 (7.07.2022): 1307. http://dx.doi.org/10.1149/ma2022-01311307mtgabs.
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After decades of relentless efforts, GaN power devices, specifically, the lateral GaN high-electron mobility transistor (HEMT), have been commercialized in the 15-650 V classes. Owing to GaN’s competitive physical properties over Si and SiC for power electronics, GaN HEMTs allow for higher switching frequency and therefore, have already seen wide adoptions in fast chargers, wireless charging, data centers, and electrified transportation. Despite the success of lateral GaN HEMTs, a vertical device structure is usually believed to be more favorable for high-voltage, high-power devices. In the last few years, with the advent and maturity of large-diameter, low-dislocation GaN wafers on freestanding GaN substrates, a new generation of vertical GaN power devices have been developed to extend GaN’s application space beyond 650 V. Very recently, several industrial vertical GaN devices in the voltage classes of 1.2-1.7 kV have been demonstrated, which are close to commercialization. This presentation will review the key advancements in vertical GaN power devices in the past decade, with a focus on the device technologies that are being commercialized, and provide a prospective for research and development in the next decade. The devices to be covered will include two-terminal power rectifiers including the p-n diodes, Schottky barrier diodes, junction barrier Schottky diodes, and trench MIS/MOS barrier Schottky diodes. The transistors will include the trench and planar MOSFETs, current-aperture vertical electron transistors, fin-channel MOSFETs, and fin-channel JFETs. Particular emphasis will be on large-area rectifiers and transistors with a device performance superior to similarly-rated Si and SiC transistors. The newly demonstrated avalanche and short-circuit robustness in vertical GaN devices, which are lacking in lateral GaN HEMTs, as well as their underlying device physics, will also be introduced. The presentation will be concluded by a discussion of current challenges and future application spaces of vertical GaN devices, as well as emerging vertical GaN devices (e.g., superjunction) under development.
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Wu, Ping, Wen Sheng Wei, Jun Ding Zheng, Wei Bo Yang, Chang Li, Ming Chang He i Yi Wan. "Optimal Design of Large Signal Performance of AlN/GaN Hetero-Structural IMPATT and MITATT Diodes". Materials Science Forum 1014 (listopad 2020): 157–62. http://dx.doi.org/10.4028/www.scientific.net/msf.1014.157.
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Hetero-structure of AlxGa1-xN/GaN exhibits important applications in high frequency and large power devices. In this paper, AlN/GaN is adopted to optimal design the large power impact avalanche transit time (IMPATT) and mixed tunneling avalanche transit time (MITATT) diodes operating at the atmospheric low loss window frequency of 0.85 THz. The static state and large signal characteristics of the devices are numerically simulated. The values of peak electric field strength, break-down voltage, avalanche voltage, the maximum generation rates of avalanche and tunneling, admittance-frequency relation, output power, conversion efficiency, quality factor of the proposed hetero-structural IMPATT and MITATT diodes are calculated, respectively. Via comparing the obtained results of (n)AlN/(p)GaN and (n)GaN/(p)AlN IMPATT diodes to those of the MITATT counterparts, there exists little performance difference between IMPATT and MITATT devices while implies significant difference between the (n)AlN/(p)GaN and (n)GaN/(p)AlN diodes.
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Zhang, Yuhao, Ruizhe Zhang, Qihao Song, Qiang Li i J. Liu. "(Invited) Breakthrough Avalanche and Short Circuit Robustness in Vertical GaN Power Devices". ECS Transactions 108, nr 6 (20.05.2022): 11–20. http://dx.doi.org/10.1149/10806.0011ecst.
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Power devices are highly desirable to possess excellent avalanche and short-circuit (or surge-current) robustness for numerous power electronics applications like automotive powertrains, electric grids, motor drives, among many others. Current commercial GaN power device, the lateral GaN high-electron-mobility transistor (HEMT), is known to have no avalanche capability and very limited short-circuit robustness. These limitations have become a roadblock for penetration of GaN devices in many industrial power applications. Recently, through collaborations with NexGen Power Systems (NexGen), Inc., we have demonstrated breakthrough avalanche, surge-current and short-circuit robustness in NexGen’s vertical GaN p-n diodes and fin-shape junction-gate field-effect-transistors (Fin-JFETs). These large-area GaN diodes and Fin-JFETs were manufactured in NexGen’s 100 mm GaN-on-GaN fab. The demonstrated avalanche, surge-current and short-circuit capabilities are comparable or even superior to Si and SiC power devices. Additionally, vertical GaN Fin-JFETs were found to fail to open-circuit under avalanche and short-circuit conditions, which is highly desirable for the system safety. This talk reviews the key robustness results of vertical GaN power devices and unveils the enabling device physics. Fundamentally, these results signify that, in contrast to some popular belief, GaN devices with appropriate designs can achieve excellent robustness and thereby encounter no barriers for applications in electric vehicles, grids, renewable processing, and industrial motor drives.
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Liu, An-Chen, Po-Tsung Tu, Catherine Langpoklakpam, Yu-Wen Huang, Ya-Ting Chang, An-Jye Tzou, Lung-Hsing Hsu, Chun-Hsiung Lin, Hao-Chung Kuo i Edward Yi Chang. "The Evolution of Manufacturing Technology for GaN Electronic Devices". Micromachines 12, nr 7 (23.06.2021): 737. http://dx.doi.org/10.3390/mi12070737.
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GaN has been widely used to develop devices for high-power and high-frequency applications owing to its higher breakdown voltage and high electron saturation velocity. The GaN HEMT radio frequency (RF) power amplifier is the first commercialized product which is fabricated using the conventional Au-based III–V device manufacturing process. In recent years, owing to the increased applications in power electronics, and expanded applications in RF and millimeter-wave (mmW) power amplifiers for 5G mobile communications, the development of high-volume production techniques derived from CMOS technology for GaN electronic devices has become highly demanded. In this article, we will review the history and principles of each unit process for conventional HEMT technology with Au-based metallization schemes, including epitaxy, ohmic contact, and Schottky metal gate technology. The evolution and status of CMOS-compatible Au-less process technology will then be described and discussed. In particular, novel process techniques such as regrown ohmic layers and metal–insulator–semiconductor (MIS) gates are illustrated. New enhancement-mode device technology based on the p-GaN gate is also reviewed. The vertical GaN device is a new direction of development for devices used in high-power applications, and we will also highlight the key features of such kind of device technology.
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UEDA, TETSUZO, YASUHIRO UEMOTO, TSUYOSHI TANAKA i DAISUKE UEDA. "GaN TRANSISTORS FOR POWER SWITCHING AND MILLIMETER-WAVE APPLICATIONS". International Journal of High Speed Electronics and Systems 19, nr 01 (marzec 2009): 145–52. http://dx.doi.org/10.1142/s0129156409006199.
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We review our state-of-the-art GaN -based device technologies for power switching at low frequencies and for future millimeter-wave communication systems. These two applications are emerging in addition to the power amplifiers at microwave frequencies which have been already commercialized for cellular base stations. Technical issues of the power switching GaN device include lowering the fabrication cost, normally-off operation and further increase of the breakdown voltages extracting full potential of GaN -based materials. We establish flat and crack-free epitaxial growth of GaN on Si which can reduce the chip cost. Our novel device structure called Gate Injection Transistor (GIT) achieves normally-off operation with high enough drain current utilizing conductivity modulation. Here we also present the world highest breakdown voltage of 10400V in AlGaN / GaN HFETs. In this paper, we also present high frequency GaN -based devices for millimeter-wave applications. Short-gate MIS-HFETs using in-situ SiN as gate insulators achieve high fmax up to 203GHz. Successful integration of low-loss microstrip lines with via-holes onto sapphire enables compact 3-stage K -band amplifier MMIC of which the small-signal gain is as high as 22dB at 26GHz. The presented devices are promising for the two future emerging applications demonstrating high enough potential of GaN -based transistors.
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Vobecký, Jan. "The current status of power semiconductors". Facta universitatis - series: Electronics and Energetics 28, nr 2 (2015): 193–203. http://dx.doi.org/10.2298/fuee1502193v.
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Trends in the design and technology of power semiconductor devices are discussed on the threshold of the year 2015. Well established silicon technologies continue to occupy most of applications thanks to the maturity of switches like MOSFET, IGBT, IGCT and PCT. Silicon carbide (SiC) and gallium nitride (GaN) are striving to take over that of the silicon. The most relevant SiC device is the MPS (JBS) diode, followed by MOSFET and JFET. GaN devices are represented by lateral HEMT. While the long term reliability of silicon devices is well trusted, the SiC MOSFETs and GaN HEMTs are struggling to achieve a similar confidence. Two order higher cost of SiC equivalent functional performance at device level limits their application to specific cases, but their number is growing. Next five years will therefore see the co-existence of these technologies. Silicon will continue to occupy most of applications and dominate the high-power sector. The wide bandgap devices will expand mainly in the 600 - 1200 V range and dominate the research regardless of the voltage class.
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Rodriguez, Jose A., Tsz Tsoi, David Graves i Stephen B. Bayne. "Evaluation of GaN HEMTs in H3TRB Reliability Testing". Electronics 11, nr 10 (11.05.2022): 1532. http://dx.doi.org/10.3390/electronics11101532.
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Gallium Nitride (GaN) power devices can offer better switching performance and higher efficiency than Silicon Carbide (SiC) and Silicon (Si) devices in power electronics applications. GaN has extensively been incorporated in electric vehicle charging stations and power supplies, subjected to harsh environmental conditions. Many reliability studies evaluate GaN power devices through thermal stresses during current conduction or pulsing, with a few focusing on high blocking voltage and high humidity. This paper compares GaN-on-Si High-Electron-Mobility Transistors (HEMT) device characteristics under a High Humidity, High Temperature, Reverse Bias (H3TRB) Test. Twenty-one devices from three manufacturers were subjected to 85 °C and 85% relative humidity while blocking 80% of their voltage rating. Devices from two manufacturers utilize a cascade configuration with a silicon metal-oxide-semiconductor field-effect transistor (MOSFET), while the devices from the third manufacturer are lateral p-GaN HEMTs. Through characterization, three sample devices have exhibited degraded blocking voltage capability. The results of the H3TRB test and potential causes of the failure mode are discussed.
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Khan, Sahanowaj, Aritra Acharyya, Hiroshi Inokawa, Hiroaki Satoh, Arindam Biswas, Rudra Sankar Dhar, Amit Banerjee i Alexey Y. Seteikin. "Terahertz Radiation from High Electron Mobility Avalanche Transit Time Sources Prospective for Biomedical Spectroscopy". Photonics 10, nr 7 (10.07.2023): 800. http://dx.doi.org/10.3390/photonics10070800.
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A Schottky barrier high-electron-mobility avalanche transit time (HEM-ATT) structure is proposed for terahertz (THz) wave generation. The structure is laterally oriented and based on AlGaN/GaN two-dimensional electron gas (2-DEG). Trenches are introduced at different positions of the top AlGaN barrier layer for realizing different sheet carrier density profiles at the 2-DEG channel; the resulting devices are equivalent to high–low, low–high and low-high–low quasi-Read structures. The DC, large-signal and noise simulations of the HEM-ATTs were carried out using the Silvaco ATLAS platform, non-sinusoidal-voltage-excited large-signal and double-iterative field-maximum small-signal simulation models, respectively. The breakdown voltages of the devices estimated via simulation were validated by using experimental measurements; they were found to be around 17–18 V. Under large-signal conditions, the series resistance of the device is estimated to be around 20 Ω. The large-signal simulation shows that the HEM-ATT source is capable of delivering nearly 300 mW of continuous-wave peak power with 11% conversion efficiency at 1.0 THz, which is a significant improvement over the achievable THz power output and efficiency from the conventional vertical GaN double-drift region (DDR) IMPATT THz source. The noise performance of the THz source was found to be significantly improved by using the quasi-Read HEM-ATT structures compared to the conventional vertical Schottky barrier IMPATT structure. These devices are compatible with the state-of-the-art medium-scale semiconductor device fabrication processes, with scope for further miniaturization, and may have significant potential for application in compact biomedical spectroscopy systems as THz solid-state sources.
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McCarthy, L. S., N.-Q. Zhang, H. Xing, B. Moran, S. DenBaars i U. K. Mishra. "High Voltage AlGaN/GaN Heterojunction Transistors". International Journal of High Speed Electronics and Systems 14, nr 01 (marzec 2004): 225–43. http://dx.doi.org/10.1142/s0129156404002314.
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The use of AlGaN / GaN HEMTs and HBTs for switching power supplies is explored. With its high electron velocities and breakdown fields, GaN has great potential for power switching. The field-plate HEMT increased breakdown voltages by 20% to 570V by reducing the peak field at the drain-side edge of the gate. The use of a gate insulator is also investigated, using both JVD SiO 2 and e-beam evaporated SiO 2 to reduce gate leakage, increasing breakdown voltages to 1050V and 1300V respectively. The power device figure of merit (FOM) for these devices: [Formula: see text], is the highest reported for switching devices. To reduce trapping effects, reactively sputtered SiN x, is used as a passivant, resulting in a switching time of less than 30 ns for devices blocking over 110V with a drain current of 1.4A under resistive load conditions. Dynamic load results are also presented. The development of HBTs for switching applications included the development of an etched emitter HBT with a selectively regrown extrinsic base. This was later improved upon with the selectively regrown emitter devices with current gains as high as 15. To improve breakdown in these devices, thick GaN layers were grown, reducing threading dislocation densities in the active layers. A further improvement included the use of a bevelled shallow etch and a lateral collector design to maximize device breakdown.
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Zhang, Wenli, Zhengyang Liu, Fred Lee, Shuojie She, Xiucheng Huang i Qiang Li. "A Gallium Nitride-Based Power Module for Totem-Pole Bridgeless Power Factor Correction Rectifier". International Symposium on Microelectronics 2015, nr 1 (1.10.2015): 000324–29. http://dx.doi.org/10.4071/isom-2015-wp11.
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The totem-pole bridgeless power factor correction (PFC) rectifier has recently gained popularity for ac-dc power conversion. The emerging gallium nitride (GaN) high-electron-mobility transistor (HEMT), having a small body diode reverse recovery effect and low switching loss, is a promising device for use in the totem-pole approach. The design, fabrication, and thermal analysis of a GaN-based full-bridge multi-chip module (MCM) for totem-pole bridgeless PFC rectifier are introduced in this work. Four cascode GaN devices using the same pair of high-voltage GaN HEMT and low-voltage silicon (Si) power metal-oxide-semiconductor field-effect transistor (MOSFET) chips, as used in the discrete TO-220 package, were integrated onto one aluminum nitride direct-bonded-copper (AlN-DBC) substrate in a newly designed MCM. This integrated power module achieves the same function as four discrete devices mounted on the circuit board. In this module design, the Si and GaN bare die were arranged in a stack-die format for each cascode device to eliminate the critical common source inductance, and thus to reduce parasitic ringing at turn-off transients. In addition, an extra capacitor was added in parallel with the drain-source terminals of the Si MOSFET in each cascode GaN device to compensate for the mismatched junction capacitance between the Si MOSFET and GaN HEMT, which could accomplish the internal zero-voltage switching of the GaN device and reduce its turn-on loss. The AlN-DBC substrate and the flip-chip format were also applied in the module design. This GaN-based MCM shows an improved heat dissipation capability based on the thermal analysis and comparison with the discrete GaN device. The totem-pole bridgeless PFC rectifier built using this integrated power module is expected to have a peak efficiency of higher than 99% with a projected power density greater than 400 W/in3.
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Wu, Nengtao, Zhiheng Xing, Shanjie Li, Ling Luo, Fanyi Zeng i Guoqiang Li. "GaN-based power high-electron-mobility transistors on Si substrates: from materials to devices". Semiconductor Science and Technology 38, nr 6 (25.04.2023): 063002. http://dx.doi.org/10.1088/1361-6641/acca9d.
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Abstract Conventional silicon (Si)-based power devices face physical limitations—such as switching speed and energy efficiency—which can make it difficult to meet the increasing demand for high-power, low-loss, and fast-switching-frequency power devices in power electronic converter systems. Gallium nitride (GaN) is an excellent candidate for next-generation power devices, capable of improving the conversion efficiency of power systems owing to its wide band gap, high mobility, and high electric breakdown field. Apart from their cost effectiveness, GaN-based power high-electron-mobility transistors (HEMTs) on Si substrates exhibit excellent properties—such as low ON-resistance and fast switching—and are used primarily in power electronic applications in the fields of consumer electronics, new energy vehicles, and rail transit, amongst others. During the past decade, GaN-on-Si power HEMTs have made major breakthroughs in the development of GaN-based materials and device fabrication. However, the fabrication of GaN-based HEMTs on Si substrates faces various problems—for example, large lattice and thermal mismatches, as well as ‘melt-back etching’ at high temperatures between GaN and Si, and buffer/surface trapping induced leakage current and current collapse. These problems can lead to difficulties in both material growth and device fabrication. In this review, we focused on the current status and progress of GaN-on-Si power HEMTs in terms of both materials and devices. For the materials, we discuss the epitaxial growth of both a complete multilayer HEMT structure, and each functional layer of a HEMT structure on a Si substrate. For the devices, breakthroughs in critical fabrication technology and the related performances of GaN-based power HEMTs are discussed, and the latest development in GaN-based HEMTs are summarised. Based on recent progress, we speculate on the prospects for further development of GaN-based power HEMTs on Si. This review provides a comprehensive understanding of GaN-based HEMTs on Si, aiming to highlight its development in the fields of microelectronics and integrated circuit technology.
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Waltereit, Patrick, Wolfgang Bronner, Rüdiger Quay, Michael Dammann, Rudolf Kiefer, Wilfried Pletschen, Stefan Müller i in. "AlGaN/GaN epitaxy and technology". International Journal of Microwave and Wireless Technologies 2, nr 1 (luty 2010): 3–11. http://dx.doi.org/10.1017/s175907871000005x.
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We present an overview on epitaxial growth, processing technology, device performance, and reliability of our GaN high electron mobility transistors (HEMTs) manufactured on 3- and 4-in. SiC substrates. Epitaxy and processing are optimized for both performance and reliability. We use three different gate lengths, namely 500 nm for 1–6 GHz applications, 250 nm for devices between 6 and 18 GHz, and 150 nm for higher frequencies. The developed HEMTs demonstrate excellent high-voltage stability, high power performance, and large DC to RF conversion efficiencies for all gate lengths. On large gate width devices for base station applications, an output power beyond 125 W is achieved with a power added efficiency around 60% and a linear gain around 16 dB. Reliability is tested both under DC and RF conditions with supply voltage of 50 and 30 V for 500 and 250 nm gates, respectively. DC tests on HEMT devices return a drain current change of just about 10% under IDQ conditions. Under RF stress the observed change in output power density is below 0.2 dB after more than 1000 h for both gate length technologies.
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Wang, Peng-Fei, Min-Han Mi, Meng Zhang, Qing Zhu, Jie-Jie Zhu, Yu-Wei Zhou, Jun-Wen Chen i in. "Demonstration of 16 THz V Johnson's figure-of-merit and 36 THz V fmax·VBK in ultrathin barrier AlGaN/GaN HEMTs with slant-field-plate T-gates". Applied Physics Letters 120, nr 10 (7.03.2022): 102103. http://dx.doi.org/10.1063/5.0080320.
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In this work, ultrathin barrier (∼6 nm) AlGaN/GaN high-electron-mobility transistors (HEMTs) with in situ SiN gate dielectric and slant-field plate (SFP) T-gates were fabricated and analyzed. Since the proposed scheme of gate dielectric and SFP effectively suppresses the gate leakage and alleviates the peak electric field (E-field) around gate region, the maximum breakdown voltage ( VBK) was improved to 92 V, which is 54 V higher than that of the conventional device. The fabricated ultrathin AlGaN/GaN HEMT with 60-nm SFP-T-gate exhibited the peak fT of 177 GHz and peak fmax of 393 GHz, yielding high figure-of-merits of fT · VBK = 16 THz V and fmax·VBK = 36 THz V. Moreover, load-pull measurements at 30 GHz reveal that these devices deliver output power density ( Pout) of 4.6 W/mm at Vds = 20 V and high power-added efficiency up to 52.5% at Vds = 10 V. Essentially, the experimental results indicate that the employment of SFP and in situ SiN gate dielectric is an attractive approach to balance the breakdown and speed for millimeter wave devices.
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Carlson, Eric P., Daniel W. Cunningham, Yan Zhi Xu i Isik C. Kizilyalli. "Power Electronic Devices and Systems Based on Bulk GaN Substrates". Materials Science Forum 924 (czerwiec 2018): 799–804. http://dx.doi.org/10.4028/www.scientific.net/msf.924.799.
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Wide-bandgap power semiconductor devices offer enormous energy efficiency gains in a wide range of potential applications. As silicon-based semiconductors are fast approaching their performance limits for high power requirements, wide-bandgap semiconductors such as gallium nitride (GaN) and silicon carbide (SiC) with their superior electrical properties are likely candidates to replace silicon in the near future. Along with higher blocking voltages wide-bandgap semiconductors offer breakthrough relative circuit performance enabling low losses, high switching frequencies, and high temperature operation. ARPA-E’s SWITCHES program, started in 2014, set out to catalyze the development of vertical GaN devices using innovations in materials and device architectures to achieve three key aggressive targets: 1200V breakdown voltage (BV), 100A single-die diode and transistor current, and a packaged device cost of no more than ȼ10/A. The program is drawing to a close by the end of 2017 and while no individual project has yet to achieve all the targets of the program, they have made tremendous advances and technical breakthroughs in vertical device architecture and materials development. GaN crystals have been grown by the ammonothermal technique and 2-inch GaN wafers have been fabricated from them. Near theoretical, high-voltage (1700-4000V) and high current (up to 400A pulsed) vertical GaN diodes have been demonstrated along with innovative vertical GaN transistor structures capable of high voltage (800-1500V) and low RON (0.36-2.6 mΩ-cm2). The challenge of selective area doping, needed in order to move to higher voltage transistor devices has been identified. Furthermore, a roadmap has been developed that will allow high voltage/current vertical GaN devices to reach ȼ5/A to ȼ7/A, realizing functional cost parity with high voltage silicon power transistors.
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Loong, Ling Jin, Chockalingam Aravind Vaithilingam, Gowthamraj Rajendran i Venkatkumar Muneeswaran. "Modelling and analysis of vienna rectifier for more electric aircraft applications using wide band-gap materials". Journal of Physics: Conference Series 2120, nr 1 (1.12.2021): 012027. http://dx.doi.org/10.1088/1742-6596/2120/1/012027.
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Abstract This paper presents a comprehensive study on the switching effects of wide bandgap devices and the importance of power electronics in an aircraft application. Silicon (Si), silicon carbide (SiC), and gallium nitride (GaN) are wide bandgap devices that act as a power electronic switch in the AC-DC converter for More Electric Aircraft (MEA) applications. Therefore, it is important to observe their converting efficiency to identify the most suitable wide bandgap device among three devices for AC-DC converters in aircraft applications to provide high efficiency and high-power density. In this study, the characteristics of Si, SIC, and GaN devices are simulated using PSIM software. Also, this paper presents the performance of the Vienna rectifier for aircraft application. The Vienna rectifier using Si, SiC, and GaN devices are simulated using PSIM software for aircraft application. GaN with Vienna rectifier provides better performance than Si and SiC devices for aircraft applications among the three devices. It gives high efficiency, high power density, low input current THD to meet IEEE-519 standard, and high-power factor at mains.
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Hikita, Masahiro, Hiroaki Ueno, Hisayoshi Matsuo, Tetsuzo Ueda, Yasuhiro Uemoto, Kaoru Inoue, Tsuyoshi Tanaka i Daisuke Ueda. "Status of GaN-Based Power Switching Devices". Materials Science Forum 600-603 (wrzesień 2008): 1257–62. http://dx.doi.org/10.4028/www.scientific.net/msf.600-603.1257.
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State-of-the-art technologies of GaN-based power switching transistors are reviewed, in which normally-off operation and heat spreading as technical issues. We demonstrate a new operation principle of GaN-based normally-off transistor called Gate Injection Transistor (GIT). The GIT utilizes hole-injection from p-AlGaN to AlGaN/GaN hetero-junction which increases electron density in the depleted channel resulting in dramatic increase of the drain current owing to conductivity modulation. The fabricated GIT on Si substrate exhibits the threshold voltage of +1.0V with high maximum drain current of 200mA/mm. The obtained on-state resistance (Ron·A) and off-state breakdown voltage (BVds) are 2.6mΩ·cm2 and 800V, respectively. These values are the best ones ever reported for GaN-based normally-off transistors. In addition, we propose the use of poly-AlN as surface passivation. The AlN has at least 200 times higher thermal conductivity than conventional SiN so that it can effectively reduce the channel temperature.
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Kitchen, Jennifer, Soroush Moallemi i Sumit Bhardwaj. "Multi-chip module integration of Hybrid Silicon CMOS and GaN Technologies for RF Transceivers". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2019, DPC (1.01.2019): 000339–82. http://dx.doi.org/10.4071/2380-4491-2019-dpc-presentation_tp1_010.
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Digital transceiver architectures offer the potential for achieving wireless hardware flexibility to frequency and modulation scheme for future-generation communications systems. Additionally, digital transmitters lend themselves to the use of switch-mode power amplifiers, which can have significantly higher efficiency than their linear counterparts. Two proposed architectures for realizing digital transmitters will be described in this work, both of which employ a hybrid combination of silicon integrated circuits (IC) and a power technology (e.g. GaN). This hybrid architecture takes advantage of the silicon to implement the high-complexity signal processing required for wireless communications, and uses power devices with high power density and low parasitic capacitance to sufficiently amplify the RF signals for transmission. Unfortunately, interfacing the low-power RF switching signals with off-chip high-power devices poses numerous design challenges, including: generation of integrated silicon power drivers with sufficient voltage swing for controlling power devices such as GaN, mitigation of on-chip current transients, wideband assembly interface from the silicon IC to the power device, and full system design verification using multiple process technologies. This work presents two CMOS driver architectures that can be used to interface low-power CMOS processing circuits with off-chip high-power devices. This work also details the performance limitations when assembling and interfacing multiple process technologies that are not co-located on the same IC. The main function of the driver circuitry within the digital transceiver system is to interface the low-power digital modulator to a large, high capacitance, off-chip power device. The driver must provide adequate transient current to charge/discharge the off-chip power devices' input capacitance through parasitic routing. Furthermore, the driver is designed to exhibit rise/fall times of less than 5% of the switching period and low jitter to meet RF signal quality requirements. Since silicon process technologies typically have much lower voltage breakdowns than those required to drive a power devie (e.g. GaN device), special driver architectures must be implemented to ensure the CMOS devices never exceed their breakdown voltages. Two architectures were implemented within this work to simultaneously achieve RF switching speeds and 5V signal swing from a 0.9V silicon CMOS process technology. The two architectures are: 1) a House-of-Cards configuration, and 2) a Cascode topology. These architectures will be detailed and compared with respect to performance in this presentation. Two of the most common techniques to assemble and connect a silicon IC, which includes the driver circuitry, and a (GaN) power device are: 1) direct wire bonding or flip-chip connection from the IC to the GaN, and 2) connection through a board or package interface circuit. Since most high-performance RF power devices such as GaN have negative threshold voltage, the driver (CMOS) IC must either: 1) have a supply and ground that are shifted to negative voltage values, or 2) decouple the IC's output from the GaN device's input in order to properly control the GaN. Off-chip decoupling is more easily implemented, but may limit maximum operating frequencies due to the added interface network and board/module parasitics. This work shall detail the interface models and compare the assembly procedures and potential performance limits when using both of these most common assembly techniques.
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Neufeld, Carl, Geetak Gupta, Philip Zuk i Likun Shen. "(Invited) Advances in High Power, High Voltage, Reliable GaN Products for Multi Kilo-Watt Power Conversion Applications." ECS Meeting Abstracts MA2022-02, nr 37 (9.10.2022): 1345. http://dx.doi.org/10.1149/ma2022-02371345mtgabs.
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Gallium Nitride has been proven to be a superior material system for high performance, reliable, high power transistors enabling high efficiency in power conversion applications [1,2]. In this paper we highlight some recent advances in GaN technology which expand the capabilities and applications of GaN power switches. Transphorm, Inc, is a pioneer and leader in GaN power electronics with a wide product portfolio of products spanning <100W to >10kW applications with JEDEC and AEC-Q101 qualified products including qualified 650V and 900V products (Fig. 1), as well as demonstrated 1200V devices in development. Transphorm’s vertical integration allows for control over device design, GaN epitaxial growth, and device fabrication resulting in industry leading performance and reliability. Transphorm’s breadth of volume production applications from 45 W through 10 kW is in part due to its impressive Failure in Time (FIT) rate of < 0.3 failures per billion hours is based on Field Reliability Data collected over 40 billion hours.[3] Transphorm’s normally-off devices are built by combining a state-of-the-art high voltage (HV) GaN HEMT with a low voltage (LV) Silicon MOSFET into a cascode GaN FET configuration to offer superior reliability, performance, and ease of use. The LV Si MOSFET features low gate charge and high threshold voltage which makes for a very easy to drive switch with a large gate voltage drive margin and the HV GaN HEMT offers high performance due to the superior material and transport properties of GaN combining the best of both materials. The latest GenV 15 mΩ 650V SuperGaN® FET (TP65H015G5WS) is the lowest Ron packaged GaN FET in the market enabling >10kW output powers with a single switch [4]. Inductive switching waveforms in a half-bridge at 400 V/65 A for the SuperGaN FET and SiC MOSFET were compared (Fig. 2) and the GaN device delivered current and voltage switching speeds of 4 kA/μs and 60 kV/μs which is about 2x faster than that of the SiC MOSFET, resulting in a 50% reduction in switching loss. To assess the performance of the SuperGaN FET vs similarly rated SiC MOSFETs and SiC JFETs, the devices were configured into a 240V:400V boost converter operating at 70kHz (Fig. 3). The GaN FET based boost converter was able to operate up to 12kW of output power with a maximum junction temperature of just 139 oC while the SIC MOSFET and JFET boost converters were limited 11kW and 9.2kW respectively due to junction temperature reaching 165oC. At 9.2Wk output power, the SuperGaN FET power loss was 38% and 21% lower than the loss in the SiC JFET and SiC MOSFET respectively. This combination of lower temperature and higher output power demonstrates the importance of the high efficiency of the SuperGaN FET. The unparalleled efficiency of Transphorm’s SuperGaN FETs has enabled to the development of unique products such as a 3KVA datacenter UPS released by and industry leading supplier, which is the smallest, lightest, and most powerful 3KA datacenter UPS on the market with 93.3% peak efficiency and 2.5x higher power density which enabled the form factor to shrink form a 2U to 1U enclosure. Until recently, commercial GaN power electronic devices have only available up to 650V with Transphorm’s qualified 900V GaN FET (TP90H050WS) device being the exception. We have recently announced a breakthrough in GaN technology with the demonstration of a 1200V, 70mΩ lateral GaN FET in a TO-247 package The 1200V GaN FET achieved > 99% peak efficiency in a 450V:900V synchronous boost converter operating at 50kHz which is similar to the peak efficiency of our 650V Gen IV and Gen V products. Additionally, the 1200V GaN FET achieved higher efficiency than a similarly rated state-of-the-art 1200V SIC MOSFET in a 900V:450V buck converter at 100kHz and 5.5kW (Fig 4) demonstrating GaN can excel in 1200V applications [5]. [1] Y.F. Wu, J. Gritters, L. Shen, R.P. Smith, J. McKay, R. Barr, R. Birkhahn, “Performance and robustness of first generation 600-V GaN-on-Si power transistors”, The 1st IEEE Workshop on Wide Bandgap Power Devices and Applications, 6-10, Oct, 2013. [2] Parikh, Y.F. Wu, L.K. Shen, "Commercialization of High 600V GaN-on-Silicon Power Devices", Materials Science Forum, Vols. 778-780, pp. 1174-1179, October 2014. [3] https://www.transphormusa.com/en/gan-technology/#quality-reliability [4] C. J. Neufeld, Y.-F. Wu, S. Wienecke, R.P. Smith, Y. Huang, M. Kamiyama, J. Ikeda, T. Hosoda,B. Swenson and R. Birkhahn, “650V/780A GaN Power HEMT Enabling 10kW-Class High-efficiency Power Conversion”, IEEE 8th Workshop on Wide Bandgap Power Devices and Applications, 7-11 Nov. 2021. [5] Gupta, et al. IEEE International Symposium on Power Semiconductor Devices 2022 (accepted for publication) Figure 1
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Roberts, J., T. MacElwee i L. Yushyna. "The Thermal Integrity of Integrated GaN Power Modules". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2013, HITEN (1.01.2013): 000061–68. http://dx.doi.org/10.4071/hiten-mp12.
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In this paper the authors describe GaN (gallium nitride) power switching transistors that use copper post and substrate via interconnect techniques. These transistors can be matrixed to allow a parallel array of the devices to provide very low on-resistance and high operating voltages. At 150 °C the basic building block which is a 2 × 2 mm die, provides 1200 V / 14 A. A 2×2 matrix array of these transistors provides for example, 1200 V / 56 A operation. The overall GaN device size is 4 × 4 mm. This high current density is achieved by using a unique castellated island topology. This provides short fingers that are not required to carry high current. No high current tracks are provided on-chip because on-chip metal is typically less than 3 microns thick. The die has 12 copper posts on the source islands that carry the current to the CMOS driver device. The CMOS driver is used in a cascode configuration which allows the normally-on GaN transistor to be operated with convenient normally-off functionality. The two devices are combined in a modular assembly. The paper provides a thermal analysis of the assembly. The objective of the design is to keep the ‘junction’ temperature of the GaN transistor below 150 °C.
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Sugimoto, M., H. Ueda, T. Uesugi i T. kachi. "WIDE-BANDGAP SEMICONDUCTOR DEVICES FOR AUTOMOTIVE APPLICATIONS". International Journal of High Speed Electronics and Systems 17, nr 01 (marzec 2007): 3–9. http://dx.doi.org/10.1142/s012915640700414x.
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In this paper, we discuss requirements of power devices for automotive applications, especially hybrid vehicles and the development of GaN power devices at Toyota. We fabricated AlGaN/GaN HEMTs and measured their characteristics. The maximum breakdown voltage was over 600V. The drain current with a gate width of 31mm was over 8A. A thermograph image of the HEMT under high current operation shows the AlGaN/GaN HEMT operated at more than 300°C. And we confirmed the operation of a vertical GaN device. All the results of the GaN HEMTs are really promising to realize high performance and small size inverters for future automobiles.
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Kong, Cen, Jian Jun Zhou, Jin Yu Ni, Yue Chan Kong i Tang Sheng Chen. "High Breakdown Voltage GaN Power HEMT on Si Substrate". Advanced Materials Research 805-806 (wrzesień 2013): 948–53. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.948.
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GaN high electronic mobility transistor (HEMT) was fabricated on silicon substrate. A breakdown voltage of 800V was obtained without using field plate technology. The fabrication processes were compatible with the conventional GaN HEMTs fabrication processes. The length between drain and gate (Lgd) has a greater impact on breakdown voltage of the device. A breakdown voltage of 800V with maximum current density of 536 mA/mm was obtained while Lgd was 15μm and the Wg was 100μm. The specific on-state resistance of this devices was 1.75 mΩ·cm2, which was 85 times lower than that of silicon MOSFET with same breakdown voltage. The results establish the foundation of low cost GaN HEMT power electronic devices.
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Green, B., H. Henry, K. Moore, J. Abdou, R. Lawrence, F. Clayton, M. Miller i in. "A GAN ON SIC HFET DEVICE TECHNOLOGY FOR WIRELESS INFRASTRUCTURE APPLICATIONS". International Journal of High Speed Electronics and Systems 17, nr 01 (marzec 2007): 11–14. http://dx.doi.org/10.1142/s0129156407004151.
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This paper presents Freescale's baseline GaN device technology for wireless infrastructure applications. At 48 V drain bias and 2.1 GHz operating frequency 10-11 W/mm, 62-67% power-added efficiency (PAE) is realized on 0.3 mm devices and 74 W (5.9 W/mm), 55% PAE is demonstrated for 12.6 mm devices. A simple thermal model shows that a more than twofold increase in channel temperature is responsible for limiting the CW power density on the 12.6 mm compared to 0.3 mm devices. The addition of through wafer source vias to improve gain and tuning the device in a fixture optimized for efficiency yield an output power of 57W (4.7 W/mm), PAE of 66%, and a calculated channel temperature of approximately 137°C at a 28 V bias.
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Henning, Stephan W., Luke Jenkins, Sidni Hale, Christopher G. Wilson, John Tennant, Justin Moses, Mike Palmer i Robert N. Dean. "Manual Assembly of 400um Bumped-Die GaN Power Semiconductor Devices". International Symposium on Microelectronics 2012, nr 1 (1.01.2012): 000514–23. http://dx.doi.org/10.4071/isom-2012-poster_hale.
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Until recently, power semiconductors were usually produced as TO, power-PAK, and D-PAK style packaging, due to die size, thermal dissipation requirements, and the vertical flow of current through the devices. The introduction of GaN to power semiconductors has allowed manufactures to produce devices with approximately 9% the footprint of similar rated D-PAK Si MOSFETs. In addition, GaN semiconductors have much better theoretical limits of specific on-resistance to breakdown voltage, when compared to Si and SiC. As of now, GaN devices offer very good performance at much less the cost of SiC, very small footprints, no reverse recovery losses of a body diode, very low RDS(ON), and very fast turn-on and turn-off times due to QGS in single-digit nC range. GaN semiconductors are expected to make vast improvements over the next decade. Unfortunately, this decrease in package size has made design prototyping significantly more challenging. Traditional manual solder iron assembly is not sufficient for these devices. Difficulties include board design, device handling, alignment, solder reflow, flux residue removal, and post-assembly inspection. The EPC 2014 and 2015 devices both have a 4mm pitch and are 1.85mm2 and 6.70mm2, respectively. In many situations, the decreased pitch and small overall size of these devices mandate the use of automated assembly equipment, such as a pick & place, to ensure quality and repeatability of assembly. However, this may not be feasible for initial prototyping, due to cost and time constraints. Here we will present a technique for manual assembly of these chip scale devices, applied specifically to the EPC 2014 and 2015. This should decrease the cost and turn time for prototype assembly when utilizing these types of chip scale packaged power semiconductor devices.
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Chao, P. C., Kanin Chu, Jose Diaz, Carlton Creamer, Scott Sweetland, Ray Kallaher, Craig McGray, Glen D. Via i John Blevins. "GaN-on-Diamond HEMTs with 11W/mm Output Power at 10GHz". MRS Advances 1, nr 2 (2016): 147–55. http://dx.doi.org/10.1557/adv.2016.176.
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ABSTRACTA new device-first low-temperature bonded gallium nitride (GaN)-on-diamond high-electronic mobility transistor (HEMT) technology with state-of-the-art, radio frequency (RF) power performance is described. In this process, the devices were first fabricated on a GaN-on-silicon carbide (SiC) epitaxial wafer and were subsequently separated from the SiC and bonded onto a high-thermal-conductivity diamond substrate. Thermal measurements showed that the GaN-on-diamond devices maintained equivalent or lower junction temperatures than their GaN-on-SiC counterparts while delivering more than three-times higher RF power within the same active area. Such results demonstrate that the GaN device transfer process is capable of preserving intrinsic transistor electrical performance while taking advantage of the excellent thermal properties of diamond substrates. Preliminary step-stress and room-temperature, steady-state life testing shows that the low-temperature bonded GaN-on-diamond device has no inherently reliability limiting factor. GaN-on-diamond is ideally suited to wideband electronic warfare (EW) power amplifiers as they are the most thermally challenging due to continuous wave (CW) operation and the reduced power-added efficiency obtained with ultra-wide bandwidth circuit implementations.
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Faqir, M., A. Manoi, T. Mrotzek, S. Knippscheer, M. Massiot, M. Buchta, H. Blanck, S. Rochette, O. Vendier i M. Kuball. "New GaN Power-Electronics Packaging Solutions: A Thermal Analysis Using Raman Thermography". Journal of Microelectronics and Electronic Packaging 8, nr 3 (1.07.2011): 110–13. http://dx.doi.org/10.4071/imaps.297.
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Raman thermography measurements were performed on AlGaN/GaN multifinger high electron mobility transistors (HEMTs) to determine their channel temperature at various power levels. The devices were mounted on both silver diamond composite and CuW baseplates, in order to benchmark the thermal performance of novel diamond composite baseplates compared with traditional materials. We illustrate that AlGaN/GaN HEMT devices mounted on silver diamond composite baseplates show peak temperatures that are 50% lower than the peak temperatures exhibited by devices mounted on traditional CuW baseplates. This is a dramatic improvement in terms of heat extraction as a basis to enable longer device lifetimes and better performance. In addition, time-resolved Raman thermography measurements were carried out to obtain the thermal dynamics of devices on the silver-diamond baseplate and on heat diffusion during pulsed device operation. This time-dependent information is of great importance for reliability and failure analyses, as pulsed operation of a HEMT is a typical device operation condition. Finite-element thermal simulations were performed for comparison with experimental results, and good agreement with the experimental data was obtained.
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Lee, Chwan Ying, Yung Hsiang Chen, Lurng Shehng Lee, Chien Chung Hung, Cheng Tyng Yen, Suh Fang Lin, Rong Xuan, Wei Hung Kuo, Tzu Kun Ku i Ming Jinn Tsai. "Performance Comparison of GaN Power Transistors and Investigation on the Device Design Issues". Materials Science Forum 717-720 (maj 2012): 1303–6. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.1303.
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One normally-on N-channel AlGaN/GaN device and two types of normally-off GaN devices have been studied. The normally-on device with Sapphire substrate shows good Idsatand breakdown characteristics, but the gate leakage current is quite large. The first normally-off GaN hybrid metal insulator semiconductor – high electron mobility transistor (MIS-HEMT) grown on Si substrate exhibits good performance with positive threshold voltage of 3V and the breakdown voltage of over 1800V. However the second normally-off GaN MOSFET structure is rather difficult to exhibit good blocking characteristic compared to GaN MIS-HEMT device due to inadequate device design.
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Mudiyanselage, Dinusha Herath, Dawei Wang, Yuji Zhao i Houqiang Fu. "Intersubband transitions in nonpolar and semipolar III-nitrides: Materials, devices, and applications". Journal of Applied Physics 131, nr 21 (7.06.2022): 210901. http://dx.doi.org/10.1063/5.0088021.
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In the last two decades, the third-generation wide bandgap semiconductor III-nitrides have revolutionized a myriad of electronic and photonic devices and applications, including power electronics, extreme-environment electronics, RF amplifiers, and optoelectronics such as light-emitting diodes and laser diodes. Recently, III-nitride heterostructures (e.g., AlGaN/GaN) based intersubband transition (ISBT) has garnered considerable research interest for infrared (IR), terahertz (THz), and ultrafast optoelectronics (e.g., photodetectors and quantum cascade lasers) due to its large conduction band offset, large optical phonon energy, and promising room-temperature operation. This paper presents a comprehensive review on the recent progress and challenges of III-nitrides based ISBT from the perspectives of materials, structures, devices, and applications, with a focus on nonpolar and semipolar III-nitrides. Various device structures have been demonstrated for III-nitrides based ISBT, including quantum wells, dots, and wires, among which AlGaN/GaN quantum wells are the most widely used. The effects of device parameters, crystal orientations, and doping on the ISBT properties of AlGaN/GaN quantum wells are discussed. Although the room-temperature operation is still elusive, theoretical and experimental studies show that nonpolar and semipolar III-nitrides based ISBT exhibits tunable ISBT wavelength from far-IR to THz spectral range with higher efficiency compared with polar c-plane ISBT. This review can serve as a gateway to and an important reference for the recent progress and challenges of III-nitrides based ISBT and its potential applications in sensing, communication, ultrafast optoelectronics, and integrated photonics.
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Musumeci, Salvatore, Fabio Mandrile, Vincenzo Barba i Marco Palma. "Low-Voltage GaN FETs in Motor Control Application; Issues and Advantages: A Review". Energies 14, nr 19 (6.10.2021): 6378. http://dx.doi.org/10.3390/en14196378.
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The efficiency and power density improvement of power switching converters play a crucial role in energy conversion. In the field of motor control, this requires an increase in the converter switching frequency together with a reduction in the switching legs’ dead time. This target turns out to be complex when using pure silicon switch technologies. Gallium Nitride (GaN) devices have appeared in the switching device arena in recent years and feature much more favorable static and dynamic characteristics compared to pure silicon devices. In the field of motion control, there is a growing use of GaN devices, especially in low voltage applications. This paper provides guidelines for designers on the optimal use of GaN FETs in motor control applications, identifying the advantages and discussing the main issues. In this work, primarily an experimental evaluation of GaN FETs in a low voltage electrical drive is carried out. The experimental investigation is obtained through two different experimental boards to highlight the switching legs’ behavior in several operative conditions and different implementations. In this evaluative approach, the main GaN FETs’ technological aspects and issues are recalled and consequently linked to motion control requirements. The device’s fast switching transients combined with reduced direct resistance contribute to decreased power losses. Thus, in GaN FETs, a high switching frequency with a strong decrease in dead time is achievable. The reduced dead time impact on power loss management and improvement of output waveforms quality is analyzed and discussed in this paper. Furthermore, input filter capacitor design matters correlated with increasing switching frequency are pointed out. Finally, the voltage transients slope effect (dv/dt) is considered and correlated with low voltage motor drives requirements.
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Faqir, M., A. Manoi, T. Mrotzek, S. Knippscheer, M. Massiot, M. Buchta, H. Blanck, S. Rochette, O. Vendier i M. Kuball. "New GaN Power-Electronics Packaging Solutions: A Thermal Analysis using Raman Thermography". International Symposium on Microelectronics 2010, nr 1 (1.01.2010): 000446–49. http://dx.doi.org/10.4071/isom-2010-wa3-paper3.
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Raman thermography measurements were performed on AlGaN/GaN multi-finger high electron mobility transistors (HEMTs) to determine their channel temperature at various power levels. The devices were mounted on both silver diamond composite and CuW base plates, in order to benchmark the thermal performance of novel diamond composite base plates compared to traditional materials. We illustrate that AlGaN/GaN HEMT devices mounted on silver diamond composite base plates show peak temperatures which are 50% lower than the peak temperatures exhibited by devices mounted on traditional CuW base plates. This is a dramatic improvement in terms of heat extraction, as basis to enabling longer device life-times and better performances. In addition, time-resolved Raman thermography measurements were carrier out to obtain thermal dynamics of devices on the silver-diamond base plate and on heat diffusion during pulsed device operation. This time-dependent information is of great importance for reliability and failure analyses, as pulsed operation of a HEMT is a typically device operation condition. Finite-element thermal simulations were performed for comparison with the experimental results, and good agreement with the experimental data was obtained.
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Soh, Mei, T. Teo, S. Selvaraj, Lulu Peng, Don Disney i Kiat Yeo. "Heterogeneous Integration of GaN and BCD Technologies". Electronics 8, nr 3 (22.03.2019): 351. http://dx.doi.org/10.3390/electronics8030351.
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Light-emitting diodes (LEDs) are solid-state devices that are highly energy efficient, fast switching, have a small form factor, and can emit a specific wavelength of light. The ability to precisely control the wavelength of light emitted with the fabrication process enables LEDs to not only provide illumination, but also find applications in biology and life science research. To enable the new generation of LED devices, methods to improve the energy efficiency for possible battery operation and integration level for miniaturized lighting devices should be explored. This paper presents the first case of the heterogeneous integration of gallium nitride (GaN) power devices, both GaN LED and GaN transistor, with bipolar CMOS DMOS (BCD) circuits that can achieve this. To validate this concept, an LED driver was designed, implemented and verified experimentally. It features an output electrical power of 1.36 W and compact size of 2.4 × 4.4 mm2. The designed fully integrated LED lighting device emits visible light at a wavelength of approximately 454 nm and can therefore be adopted for biology research and life science applications.
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Wang, Li, i Chun Feng. "The International Research Progress of GaN-Based Microwave Electronic Devices". Advanced Materials Research 1053 (październik 2014): 69–73. http://dx.doi.org/10.4028/www.scientific.net/amr.1053.69.
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The international research progress of GaN-based high frequency, high power microwave electronic device is introduced. The latest developments in high efficiency and millimeter wave devices are especially described.
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Amit, Mr, Dipendra Singh Rawal, Sunil Sharma, Sonalee Kapoor, Robert Liashram, Rupesh K. Chaubey, Seema Vinayak i Rajesh K. Sharma. "Design and Fabrication of Multi-finger Field Plate for Enhancement of AlGaN/GaN HEMT Breakdown Voltage". Defence Science Journal 68, nr 3 (16.04.2018): 290. http://dx.doi.org/10.14429/dsj.68.12134.
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The design and fabrication of gate/source connected multi-finger field plate structures using TCAD ATLAS simulation software is presented. The designed field plate structures are fabricated on indigenous AlGaN/GaN HEMT devices. AlGaN/GaN HEMT devices with field plate structures exhibit about three times improvement in breakdown voltage of device and are in close agreement with the simulation results. Integration of field plates in device have resulted in higher VDS (drain to source voltage) operation and improvement in output power of AlGaN/GaN HEMT devices. Incorporation of field plates also decrease the reverse leakage current of HEMT devices.
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Rugen, Sarah, Alexander Brunko, Felix Hoffmann i Nando Kaminski. "Power Cycling on Lateral GaN and β-Ga<sub>2</sub>O<sub>3</sub> Transistors". Materials Science Forum 1092 (6.06.2023): 157–64. http://dx.doi.org/10.4028/p-gv3hl2.
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The load cycling capability of novel power semiconductors is an important aspect when estimating their lifetime in field service. The Power Cycling Test (PCT) is the standard test to evaluate the lifetime of a semiconductor device under thermo-mechanical stress. PCTs are typically performed at temperature swings (ΔT) much higher than common operating conditions, to obtain results within a reasonable time. In this work, the PCT capability of gallium nitride (GaN) and gallium oxide (Ga2O3) lateral transistors is investigated. The GaN devices were tested in two groups with different ΔT. The temperature of the devices was monitored using two different temperature sensitive electrical parameters (TSEPs) and the accuracy of both methods was evaluated by comparing the results with the temperature, monitored by using an infrared (IR) camera. For Ga2O3 devices, no data on potential TSEP exists so far, thus, the typical TSEP for silicon (Si), silicon carbide (SiC) and GaN were investigated for their applicability to Ga2O3 devices. While a PCT was conducted on the devices, the temperature was also monitored using an IR camera. The results of the comparison of TSEP and IR camera data showed, that the accuracy of the TSEP for GaN matched either the temperature of the hottest spot on the chip (VDS method), or the average chip temperature (VGS method). For the Ga2O3 devices no suitable TSEP could be obtained and only the IR camera was used for the temperature measurement. It revealed a very uneven temperature and thus, current distribution on the chip. Furthermore, both GaN and Ga2O3 devices exhibit an outstanding power cycling capability with no failure after completing several millions of cycles. Considering the difference in Young’s Modulus of Si, GaN and Ga2O3, the PCT performance of GaN on silicon devices and Ga2O3 devices should be inferior to silicon devices. Thus, both device types, the GaN transistors and the Ga2O3 transistors, showed a PCT capability much higher than expected.
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Islam, Naeemul, Mohamed Fauzi Packeer Mohamed, Muhammad Firdaus Akbar Jalaludin Khan, Shaili Falina, Hiroshi Kawarada i Mohd Syamsul. "Reliability, Applications and Challenges of GaN HEMT Technology for Modern Power Devices: A Review". Crystals 12, nr 11 (7.11.2022): 1581. http://dx.doi.org/10.3390/cryst12111581.
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A new generation of high-efficiency power devices is being developed using wide bandgap (WBG) semiconductors, like GaN and SiC, which are emerging as attractive alternatives to silicon. The recent interest in GaN has been piqued by its excellent material characteristics, including its high critical electric field, high saturation velocity, high electron mobility, and outstanding thermal stability. Therefore, the superior performance is represented by GaN-based high electron mobility transistor (HEMT) devices. They can perform at higher currents, voltages, temperatures, and frequencies, making them suitable devices for the next generation of high-efficiency power converter applications, including electric vehicles, phone chargers, renewable energy, and data centers. Thus, this review article will provide a basic overview of the various technological and scientific elements of the current GaN HEMTs technology. First, the present advancements in the GaN market and its primary application areas are briefly summarized. After that, the GaN is compared with other devices, and the GaN HEMT device’s operational material properties with different heterostructures are discussed. Then, the normally-off GaN HEMT technology with their different types are considered, especially on the recessed gate metal insulator semiconductor high electron mobility transistor (MISHEMT) and p-GaN. Hereafter, this review also discusses the reliability concerns of the GaN HEMT which are caused by trap effects like a drain, gate lag, and current collapse with numerous types of degradation. Eventually, the breakdown voltage of the GaN HEMT with some challenges has been studied.
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Ahmed, Osama, Yousuf Khan, Muhammad A. Butt, Nikolay L. Kazanskiy i Svetlana N. Khonina. "Performance Comparison of Silicon- and Gallium-Nitride-Based MOSFETs for a Power-Efficient, DC-to-DC Flyback Converter". Electronics 11, nr 8 (12.04.2022): 1222. http://dx.doi.org/10.3390/electronics11081222.
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Gallium Nitride (GaN)-based devices offer many advantages over conventional electronic devices, such as lower input/output capacitances, a higher switching speed, and a compact size, resulting in higher-density power outputs and reduced switching losses. This research investigates the power and switching efficiency of GaN-based FET in an active-clamp, DC-to-DC flyback converter for step-down application (24 V to 7 V) and compares it with silicon (Si)- based devices in the same circuit topology. The operation is analyzed under various input conditions and output loads such as R, RC, RL, and RLC. The proposed topology can achieve a maximum power-conversion efficiency of 99.6% and can operate at higher frequency values above 1 MHz. The presented GaN-based flyback model can replace conventional Si-based switches in power applications which require high power-efficiency and switching speed in a compact device.
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MANOHAR, S., A. PHAM, J. BROWN, R. BORGES i K. LINTHICUM. "MICROWAVE GaN-BASED POWER TRANSISTORS ON LARGE-SCALE SILICON WAFERS". International Journal of High Speed Electronics and Systems 13, nr 01 (marzec 2003): 265–75. http://dx.doi.org/10.1142/s0129156403001600.
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This paper presents the development of microwave Gallium nitride (GaN) heterostructure field-effect transistors (HFETs) on silicon (Si). GaN-on-Si provides a low-cost manufacturable platform that could lead to the commercialization of GaN-based power devices for wireless applications. Small periphery GaN high electron mobility transistors (HEMTs) on Si exhibited a maximum drain current of 900mA/mm, a peak gm of 300 mS/mm, and a microwave output power density of 1.5 W/mm at 2 GHz. Microwave characterization and device modeling of GaN HEMTs on Si are discussed.
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Cole, Z., B. McGee, J. Stabach, C. B. O'Neal i B. Passmore. "A High Temperature, High Power Density Package for SiC and GaN Power Devices". Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2015, HiTEN (1.01.2015): 000208–13. http://dx.doi.org/10.4071/hiten-session6-paper6_3.
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In this work, a compact 600 – 1700 V high current power package housing either silicon carbide (SiC) or gallium nitride (GaN) power die was designed and developed. Several notable configurations of the package include diode half-bridges, co-packed MOSFET-diode pairs, and cascode configured GaN devices. In order to avoid a significant redesign effort for each new application or improvement in device technology, a device-neutral design strategy enables the use of a variety of die types from any manufacturer depending on the end-use application's requirements. The basic SOT-227 is a widely used package type found in everything from electronic welders and power supplies to motor controls and inverters. This module is a variant of that style of package which also addresses some issues that a standard SOT-227 package has when used in higher voltage applications; it has increased creepage and clearance distances which meet IPC, UL, and IEC standards up to 1700 volts while retaining an isolated substrate. It also has low parasitic values in comparison to the SOT-227. One of the key elements of this design is the removal of the baseplate. This allows for far lower weight, volume, and cost as well as reduced manufacturing complexity. The wide bandgap power package is composed of high temperature capable materials, which allow for the high junction temperatures inherent in these high power density devices. This paves the way for the design of a small, low-profile package with low parasitic inductances and a small junction-to-case thermal resistance. This paper will discuss the mechanical design of the power package as well as the three-dimensional finite-element modeling and analysis of the thermal, electrical, and mechanical characteristics. In addition, the electrical characteristics as a function of temperature of the power module up to 225 °C will be presented.
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Uren, Michael J., i Martin Kuball. "Advances in AlGaN/GaN/SiC Microwave Devices". Materials Science Forum 556-557 (wrzesień 2007): 1017–22. http://dx.doi.org/10.4028/www.scientific.net/msf.556-557.1017.
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Recent work on the thermal and electrical challenges in realizing AlGaN/GaN microwave heterojunction field effect transistors grown on SiC substrates is discussed. Raman thermography has been used to directly measure the self-heating induced lattice temperature rise with dramatically improved resolution and accuracy compared to traditional infrared techniques. It is demonstrated that defects in the SiC substrate can influence the temperature distribution within the active device with potential consequences for reliability. Microwave devices require an insulating GaN substrate material for device isolation. It is shown that the net deep level acceptor concentration has to be accurately controlled to suppress short-channel effects and to achieve radio frequency power efficient operation.
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Cui, Yixin, Yingqi Ma, Shipeng Shangguan i Jianwei Han. "Study of Single Event Burnout Mechanism in GaN Power Devices Using Femtosecond Pulsed Laser". Photonics 9, nr 4 (18.04.2022): 270. http://dx.doi.org/10.3390/photonics9040270.
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Single event burnout (SEB) is a great threat to gallium nitride (GaN) power devices for aerospace applications. This paper is dedicated to the investigation of the SEB mechanism in a GaN power device using a femtosecond pulsed laser. In the test, the SEB of a commercial p-GaN power device was triggered by a focused laser beam with a wavelength of 620 nm, and the irradiation-sensitive area of the devices was identified. We observed that the damage modes were consistent with the results of heavy ion experiments. The vertical breakdown of the drain is proposed as the dominant mechanism of SEB. We also provide a schematic representation of the leakage path formation using the electrical data obtained following laser-induced SEB. This study provides an important reference for consideration of device reliability and application prospects.
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Haziq, Muhaimin, Norshamsuri Ali, Shaili Falina, Hiroshi Kawarada i Mohd Syamsul. "Impact of Notch Structures on Transfer Characteristics of AlGaN/GaN HEMTs: A Simulation Study". Key Engineering Materials 947 (31.05.2023): 15–20. http://dx.doi.org/10.4028/p-xxb0t7.
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Lateral GaN devices, with a substantial critical breakdown field and increased mobility of two-dimensional electron gas (2DEG), are particularly promising for future power applications. Despite low power consumption by design, further improvements are required in numerous areas, including reliability concerns and switching loss, usually contributing to significant power loss. The research objective concerns the impact of different notch structures on the transfer characteristics of GaN-based high-electron-mobility transistor (HEMT) devices. Thirteen simulated models were produced using COMSOL Multiphysics, incorporating the electrical, structural, and piezoelectric effects of the device. From the results, notch-structure devices demonstrated better electrical characteristics than devices using conventional architecture, particularly a model with a double-notch design. Higher transconductance and maximum drain current were among the improvements, benefiting from the notch structure at the barrier layer.
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Bottaro, Enrico, Santi Agatino Rizzo i Nunzio Salerno. "Circuit Models of Power MOSFETs Leading the Way of GaN HEMT Modelling—A Review". Energies 15, nr 9 (7.05.2022): 3415. http://dx.doi.org/10.3390/en15093415.
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Gallium nitride high-electron-mobility transistor (GaN HEMT) is a key enabling technology for obtaining high-efficient and compact power electronic systems. At the design stage of a power converter, the proper modelling of the GaN HEMT is essential to benefit from their good features and to account for the limits of the current technology. Circuit models of power MOSFETs have been deeply investigated by academia and industry for a long time. These models are able to emulate the datasheet information, and they are usually provided by device manufacturers as netlists that can be simulated in any kind of SPICE-like software. This paper firstly highlights the similarities and differences between MOSFETs and GaN HEMTs at the datasheet level. According to this analysis, the features of MOSFET circuit models that can be adopted for GaN HEMT modelling are discussed. This task has been accomplished by overviewing the literature on MOSFETs circuit models as well as analysing manufacturers netlists, thus highlighting the models MOSFETs valid or adaptable to GaN HEMTs. The study has revealed show that some models can be adapted for the GaN HEMT devices to emulate static characteristics at room temperature while the MOSFET models of dynamic characteristics can be used for GaN HEMT devices. This study enables the devices modellers to speed up the GaN HEMT modelling thanks to the use of some well-established MOSFET models. In this perspective, some suggestions to develop accurate GaN HEMT models are also provided.
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Anucia A., Josephine, D. Gracia i Jackuline Moni D. "Comparative Analysis of Vertical Nanotube Field Effect Transistor (NTFET) Based on Channel Materials for Low Power Applications". WSEAS TRANSACTIONS ON CIRCUITS AND SYSTEMS 21 (26.02.2022): 26–33. http://dx.doi.org/10.37394/23201.2022.21.3.
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3D Vertical Nanotube Field Effect Transistors (NTFETs) with various channel materials are analysed for 5nm gate length (LG) in this research work. The DC and RF studies are performed on NTFET devices with Silicon, Gallium Nitride (GaN), and SiliconGermanium (SiGe) as channel materials. The impact of variation of channel length, channel thickness, and temperature analysis on these devices have been studied. The ION/IOFF ratio of Si-NTFET, GaN-NTFET and SiGe-NTFET are found to be 2.7×108^ , 1.08×10^9 , 1.69×10^8 respectively. GaN channel NTFET exhibits the lowest subthreshold swing (SS) of 33.1mV/dec with the highest cut-off frequency of 190 GHz. From the analysis, it is found that NTFET with GaN channel device outperforms the other two devices.
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QUAH, H. J., K. Y. CHEONG i Z. HASSAN. "FORTHCOMING GALLIUM NITRIDE BASED POWER DEVICES IN PROMPTING THE DEVELOPMENT OF HIGH POWER APPLICATIONS". Modern Physics Letters B 25, nr 02 (20.01.2011): 77–88. http://dx.doi.org/10.1142/s021798491102564x.
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Recent advances in silicon technology have pushed the silicon properties to its theoretical limits. Therefore, wide band gap semiconductors, such as silicon carbide ( SiC ) and gallium nitride ( GaN ) have been considered as a replacement for silicon. The discovery of these wide band gap semiconductors have given the new generation power devices a magnificent prospect of surviving under high temperature and hostile environments. The primary focuses of this review are the properties of GaN , the alternative substrates that can be used to deposit GaN and the substitution of SiO 2 gate dielectric with high dielectric constant (k) film. The future perspectives of AlGaN / GaN heterostructures are also discussed, providing that these structures are able to further enhance the performance of high power devices.