Artykuły w czasopismach: „GaN/AlN/Si”

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Середин, П. В., К. А. Барков, Д. Л. Голощапов, А. С. Леньшин, Ю. Ю. Худяков, И. Н. Арсентьев, А. А. Лебедев i in. "Влияние предобработки подложки кремния на свойства пленок GaN, выращенных методом хлорид-гидридной газофазной эпитаксии". Физика и техника полупроводников 55, nr 8 (2021): 704. http://dx.doi.org/10.21883/ftp.2021.08.51144.9660.

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Сообщается о росте методом хлорид-гидридной газофазной эпитаксии пленки GaN на предварительно обработанных кремниевых подложках Si(001) через буферный слой AlN. Продемонстрировано, что использование предложенной технологии привело к образованию в подложке Si переходного субслоя, дальнейший рост на котором обеспечил формирование столбчатых зерен GaN, между которыми находится тонкая прослойка фазы AlN. Эпитаксиальная пленка GaN имеет низкую величину остаточных напряжений, что нашло свое отражение в интенсивной люминесценции. Ключевые слова: хлорид-гидридная газофазная эпитаксия, фотолюминесценция, GaN, AlN, Si.

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Yang, Yibin, Lingxia Zhang i Yu Zhao. "Light Output Enhancement of GaN-Based Light-Emitting Diodes Based on AlN/GaN Distributed Bragg Reflectors Grown on Si (111) Substrates". Crystals 10, nr 9 (1.09.2020): 772. http://dx.doi.org/10.3390/cryst10090772.

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Due to the absorption of opaque Si substrates, the luminous efficiency of GaN-based light-emitting diodes (LEDs) on Si substrates is not high. So, in this work, we insert AlN/GaN distributed Bragg reflectors (DBRs) to improve the light output of GaN-based LEDs on Si (111) substrates grown via metal organic chemical vapor deposition (MOCVD). In order to obtain the highest reflectivity of the AlN/GaN DBR stop band, the growth parameters of AlN/GaN DBRs are optimized, including the growth temperature, the V/III ratio and the growth pressure. As a consequence, the interfaces of the optimal 9-pair AlN/GaN DBRs become abrupt, and the reflectivity of the DBR stop band is as high as 85.2%, near to the calculated value (92.5%). Finally, crack-free GaN-based LEDs with 5-pair AlN/GaN DBRs are grown on Si (111) substrates. The light output of the DBR-based LED is evidently enhanced by 41.8% at the injection current of 350 mA, compared with the conventional DBR-based LED without DBRs. These results pave the way for the luminous efficiency improvement of future green and red GaN-based LEDs grown on Si substrates.

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Кукушкин, С. А., А. В. Осипов, В. Н. Бессолов, Е. В. Коненкова i В. Н. Пантелеев. "Остановка и разворот дислокаций несоответствия при росте нитрида галлия на подложках SiC/Si". Физика твердого тела 59, nr 4 (2017): 660. http://dx.doi.org/10.21883/ftt.2017.04.44266.287.

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Обнаружен эффект изменения направления распространения дислокации несоответствия при росте слоев GaN на поверхности структуры AlN/SiC/Si(111). Эффект заключается в том, что при достижении слоем GaN, растущим на AlN/SiC/Si(111) определенной толщины ~300 nm, дислокации несоответствия первоначально, распространяющиеся вдоль оси роста слоя останавливаются и начинают двигаться в перпендикулярном к оси роста направлению. Построена теоретическая модель зарождения AlN и GaN на грани (111) SiC/Si, объясняющая эффект изменения направления движения дислокации несоответствия. Обнаружен экспериментально и объяснен теоретически эффект смены механизма зарождения с островкового для AlN на SiC/Si(111) на послойный при зарождении слоя GaN на AlN/SiC/Si. Авторы благодарят за финансовую поддержку Российский научный фонд (грант N 14-12-01102). Работа выполнена при использовании оборудования Уникальной научной установки (УНУ) Физика, химия и механика кристаллов и тонких пленок" ФГУН ИПМаш РАН (г. Санкт-Петербург). DOI: 10.21883/FTT.2017.04.44266.287

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Бессолов, В. Н., Е. В. Гущина, Е. В. Коненкова, С. Д. Коненков, Т. В. Львова, В. Н. Пантелеев i М. П. Щеглов. "Синтез гексагональных слоев AlN и GaN на Si(100)-подложке методом хлоридной газофазной эпитаксии". Журнал технической физики 89, nr 4 (2019): 574. http://dx.doi.org/10.21883/jtf.2019.04.47315.152-18.

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AbstractSynthesis of AlN and GaN layers on a Si(100) substrate by chloride vapor-phase epitaxy has been considered. The process includes sulfidizing of the silicon surface, nucleation and growth of an AlN layer, and then formation of a GaN/AlN structure. It has been found that in the case of a (100)Si substrate, GaN nucleates on buffer AlN layers that may have two crystallographic orientations in contrast to a Si(111) substrate, on which a buffer layer may have only one orientation. It has been shown that the treatment of the Si(100) substrate in an aqueous solution of (NH_4)_2S decreases the FWHM of the rocking curve for GaN(0002) by a factor of 1.5.

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Goswami, Ramasis, Syed Qadri, Neeraj Nepal i Charles Eddy. "Microstructure and Interfaces of Ultra-Thin Epitaxial AlN Films Grown by Plasma-Enhanced Atomic Layer Deposition at Relatively Low Temperatures". Coatings 11, nr 4 (20.04.2021): 482. http://dx.doi.org/10.3390/coatings11040482.

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We demonstrate the growth of ultra-thin AlN films on Si (111) and on a GaN/sapphire (0001) substrate using atomic layer epitaxy in the temperature range of 360 to 420 °C. Transmission electron microscopy and X-ray diffraction were used to characterize the interfaces, fine scale microstructure, and the crystalline quality of thin films. Films were deposited epitaxily on Si (111) with a hexagonal structure, while on the GaN/sapphire (0001) substrate, the AlN film is epitaxial and has been deposited in a metastable zinc-blende cubic phase. Transmission electron microscopy reveals that the interface is not sharp, containing an intermixing layer with cubic AlN. We show that the substrate, particularly the strain, plays a major role in dictating the crystal structure of AlN. The strain, estimated in the observed orientation relation, is significantly lower for cubic AlN on hexagonal GaN as compared to the hexagonal AlN on hexagonal GaN. On the Si (111) substrate, on the other hand, the strain in the observed orientation relation is 0.8% for hexagonal AlN, which is substantially lower than the strain estimated for the cubic AlN on Si(111).

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Nikishin, Sergey A., Nikolai N. Faleev, Vladimir G. Antipov, Sebastien Francoeur, Luis Grave de Peralta, George A. Seryogin, Mark Holtz i in. "High Quality AlN and GaN Grown on Si(111) by Gas Source Molecular Beam Epitaxy with Ammonia". MRS Internet Journal of Nitride Semiconductor Research 5, S1 (2000): 467–73. http://dx.doi.org/10.1557/s1092578300004658.

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We describe the growth of high quality AlN and GaN on Si(111) by gas source molecular beam epitaxy (GSMBE) with ammonia (NH3). The initial nucleation (at 1130−1190K) of an AlN monolayer with full substrate coverage resulted in a very rapid transition to two-dimensional (2D) growth mode of AlN. The rapid transition to the 2D growth mode of AlN is essential for the subsequent growth of high quality GaN, and complete elimination of cracking in thick ( > 2 μm) GaN layers. We show, using Raman scattering (RS) and photoluminescence (PL) measurements, that the tensile stress in the GaN is due to thermal expansion mismatch, is below the ultimate strength of breaking of GaN, and produces a sizable shift in the bandgap. We show that the GSMBE AlN and GaN layers grown on Si can be used as a substrate for subsequent deposition of thick AlN and GaN layers by hydride vapor phase epitaxy (HVPE).

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Tajalli, Alaleh, Matteo Borga, Matteo Meneghini, Carlo De Santi, Davide Benazzi, Sven Besendörfer, Roland Püsche i in. "Vertical Leakage in GaN-on-Si Stacks Investigated by a Buffer Decomposition Experiment". Micromachines 11, nr 1 (17.01.2020): 101. http://dx.doi.org/10.3390/mi11010101.

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We investigated the origin of vertical leakage and breakdown in GaN-on-Si epitaxial structures. In order to understand the role of the nucleation layer, AlGaN buffer, and C-doped GaN, we designed a sequential growth experiment. Specifically, we analyzed three different structures grown on silicon substrates: AlN/Si, AlGaN/AlN/Si, C:GaN/AlGaN/AlN/Si. The results demonstrate that: (i) the AlN layer grown on silicon has a breakdown field of 3.25 MV/cm, which further decreases with temperature. This value is much lower than that of highly-crystalline AlN, and the difference can be ascribed to the high density of vertical leakage paths like V-pits or threading dislocations. (ii) the AlN/Si structures show negative charge trapping, due to the injection of electrons from silicon to deep traps in AlN. (iii) adding AlGaN on top of AlN significantly reduces the defect density, thus resulting in a more uniform sample-to-sample leakage. (iv) a substantial increase in breakdown voltage is obtained only in the C:GaN/AlGaN/AlN/Si structure, that allows it to reach VBD > 800 V. (v) remarkably, during a vertical I–V sweep, the C:GaN/AlGaN/AlN/Si stack shows evidence for positive charge trapping. Holes from C:GaN are trapped at the GaN/AlGaN interface, thus bringing a positive charge storage in the buffer. For the first time, the results summarized in this paper clarify the contribution of each buffer layer to vertical leakage and breakdown.

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Follstaedt, D. M., J. Han, P. Provencio i J. G. Fleming. "Microstructure of GaN Grown on (111) Si by MOCVD". MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 397–402. http://dx.doi.org/10.1557/s1092578300002787.

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Gallium nitride was grown on (111) Si by MOCVD by depositing an AlN buffer at 1080°C followed by GaN at 1060°C. The 2.2 μm layer cracked along {1-100} planes upon cooling to room temperature, but remained adherent. We were nonetheless able to examine the material between cracks with TEM. The character and arrangement of dislocations are much like those of GaN grown on Al2O3: ∼2/3 pure edge and ∼1/3 mixed (edge + screw), arranged in boundaries around domains of GaN that are slightly misoriented with respect to neighboring material. The 30 nm AlN buffer is continuous, indicating that AlN wets the Si, in contrast to GaN on Al2O3.

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Vashishtha, Pargam, Pukhraj Prajapat, Lalit Goswami, Aditya Yadav, Akhilesh Pandey i Govind Gupta. "Stress-Relaxed AlN-Buffer-Oriented GaN-Nano-Obelisks-Based High-Performance UV Photodetector". Electronic Materials 3, nr 4 (9.12.2022): 357–67. http://dx.doi.org/10.3390/electronicmat3040029.

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Epitaxial GaN nanostructures are developed, and the influence of the AlN buffer layer (temperature modulation) on material characteristics and optoelectronic device application is assessed. The AlN buffer layer was grown on a Si (111) substrate at varying temperatures (770–830 °C), followed by GaN growth using plasma-assisted molecular beam epitaxy. The investigation revealed that the comparatively lower temperature AlN buffer layer was responsible for stress and lattice strain relaxation and was realized as the GaN nano-obelisk structures. Contrarily, the increased temperature of the AlN growth led to the formation of GaN nanopyramidal and nanowax/wane structures. These grown GaN/AlN/Si heterostructures were utilized to develop photodetectors in a metal–semiconductor–metal geometry format. The performance of these fabricated optoelectronic devices was examined under ultraviolet illumination (UVA), where the GaN nano-obelisks-based device attained the highest responsivity of 118 AW−1. Under UVA (325 nm) illumination, the designed device exhibited a high detectivity of 1 × 1010 Jones, noise equivalent power of 1 × 10−12 WHz−1/2, and external quantum efficiency of 45,000%. The analysis revealed that the quality of the AlN buffer layer significantly improved the optoelectronic performance of the device.

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Мизеров, А. М., С. А. Кукушкин, Ш. Ш. Шарофидинов, А. В. Осипов, С. Н. Тимошнев, К. Ю. Шубина, Т. Н. Березовская, Д. В. Мохов i А. Д. Буравлев. "Метод управления полярностью слоев GaN при эпитаксиальном синтезе GaN/AlN гетероструктур на гибридных подложках SiC/Si". Физика твердого тела 61, nr 12 (2019): 2289. http://dx.doi.org/10.21883/ftt.2019.12.48535.06ks.

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The effect of GaN polarity inversion from N- to Ga-face during the successive growth of GaN layers by plasma assisted molecular beam epitaxy and halide vapor phase epitaxy on hybrid SiC/Si(111) substrates was found. A new method of the formation of crack-free Ga-face GaN/AlN heterostructures on hybrid SiC/Si(111) substrates has been developed. In this method the two stage growth of GaN layers is used. At the first stage, the N-face GaN transition layer was grown on the SiC/Si(111) surface by plasma assisted molecular beam epitaxy. At the second stage, the AlN interlayer was first grown by halide vapor phase epitaxy on N-face GaN transition layer. After that the Ga-face GaN layer was synthesized by halide vapor phase epitaxy atop of the AlN interlayer. Also it was found that etching in a KOH solution affects only the N-face GaN transition layer and leads to its complete removal, which result in complete separation of the main Ga-face GaN layer from the SiC/Si(111) substrate. The method allows you to grow free from cracks and unstressed thick layers of GaN, and transfer them to the foreign substrates.

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Yamaoka, Yuya, Kazuhiro Ito, Akinori Ubukata, Toshiya Tabuchi, Koh Matsumoto i Takashi Egawa. "Effect of the formation temperature of the AlN/Si interface on the vertical-direction breakdown voltages of AlGaN/GaN HEMTs on Si substrates". MRS Advances 1, nr 50 (2016): 3415–20. http://dx.doi.org/10.1557/adv.2016.431.

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ABSTRACT In this study, the initial AlN layer and the vertical-direction breakdown voltage (VDBV) of AlGaN/GaN high-electron-mobility transistors (HEMTs) were characterized. Prior to the formation of the interface between the AlN layer and the Si substrate, only trimethylaluminum (TMA) was introduced without ammonia to control the crystal quality of initial AlN layer (TMA preflow). HEMT structures were simultaneously grown on identical AlN layers on Si substrates (AlN/Si templates) grown using different TMA preflow temperatures. The density of screw- or mixed-type dislocations in the initial AlN layer decreased as the TMA preflow temperature increased. Further, the VDBV of the HEMT structure increased as the TMA preflow temperature increased. It is supposed that the screw- or mixed-type dislocations are the possible source of the vertical leakage current in the HEMT structures. The improvement in the crystal quality of the initial AlN layer affects the increase in the VDBV of the AlGaN/GaN HEMTs on Si substrates.

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Mao, Zhigang, Stuart McKernan, C. Barry Carter, Wei Yang i Scott A. McPherson. "Defects in GaN Pyramids Grown on Si(111) Substrates by Selective Lateral Overgrowth". MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 179–84. http://dx.doi.org/10.1557/s1092578300002428.

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Selective lateral growth of GaN is a promising technique for producing high quality material for microelectronic and optoelectronic devices. Single-crystal GaN/AlN layers have been grown on Si(111) substrates and subsequently used as the seeding layer for selective lateral overgrowth. GaN pyramids are formed above holes patterned in a Si3N4 mask. Transmission electron microscopy (TEM, which also denotes the microscope) of these structures shows that the GaN pyramid, GaN seed layer, and AlN buffer layer in the samples have the following epitactic relationship with respect to the Si substrate: and (0001)GaN ∥ (0001)AlN ∥ (111)Si. In the core of the pyramid (at or above the seed windows), dislocations thread through the pyramid perpendicular to the interface plane with very high density. Some of these threading dislocations, which originate from the GaN/AlN seed layer, form 90° bends and half loops at the edge of the pyramid core. In the lateral growth part of the GaN pyramid, the dislocation density is relatively low. The majority of dislocations thread through the pyramid parallel to the interface plane. Planar defects, usually parallel to the interface plane, were observed near the interface. The defect density decreases with the distance away from the interface, so that the top several microns of material maybe completely defect free. The mechanism of the growth of GaN pyramids is discussed and related to this defect structure.

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Serban, Andreea, Vladimir Ene, Doru Dinescu, Iulia Zai, Nikolay Djourelov, Bogdan Vasile i Victor Leca. "Studies of Defect Structure in Epitaxial AlN/GaN Films Grown on (111) 3C-SiC". Nanomaterials 11, nr 5 (14.05.2021): 1299. http://dx.doi.org/10.3390/nano11051299.

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Several aspects such as the growth relation between the layers of the GaN/AlN/SiC heterostructure, the consistency of the interfaces, and elemental diffusion are achieved by High Resolution Transmission Electron Microscopy (HR-TEM). In addition, the dislocation densities together with the defect correlation lengths are investigated via High-Resolution X-ray Diffraction (HR-XRD) and the characteristic positron diffusion length is achieved by Doppler Broadening Spectroscopy (DBS). Moreover, a comparative analysis with our previous work (i.e., GaN/AlN/Si and GaN/AlN/Al2O3) has been carried out. Within the epitaxial GaN layer defined by the relationship F4¯3m (111) 3C-SiC || P63mc (0002) AlN || P63mc (0002) GaN, the total dislocation density has been assessed as being 1.47 × 1010 cm−2. Compared with previously investigated heterostructures (on Si and Al2O3 substrates), the obtained dislocation correlation lengths (Le = 171 nm and Ls =288 nm) and the mean distance between two dislocations (rd = 82 nm) are higher. This reveals an improved crystal quality of the GaN with SiC as a growth template. In addition, the DBS measurements upheld the aforementioned results with a higher effective positron diffusion length LeffGaN2 = 75 ± 20 nm for the GaN layer.

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Abe, Yoshihisa, Jun Komiyama, Toshiyuki Isshiki, Shunichi Suzuki, Akira Yoshida, Hiroshi Ohishi i Hideo Nakanishi. "Semipolar Nitrides Grown on Si(001) Offcut Substrates with 3C-SiC Buffer Layers". Materials Science Forum 600-603 (wrzesień 2008): 1281–84. http://dx.doi.org/10.4028/www.scientific.net/msf.600-603.1281.

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The growth process of semipolar GaN(10-12) on Si(001) offcut substrates with 3C-SiC buffer layers has been investigated. From XRD analysis, the difference in the crystal orientation between GaN(10-12) and 3C-SiC(001) has been found to be around 8˚ toward the [110] direction of the 3C-SiC templates. From TEM observations, a cubic-phase AlN seed layer is found to grow on 3C-SiC(001) templates, and the swift transition from the cubic phase to a hexagonal phase leads to the stable growth of hexagonal nitrides. Using 8˚-offcut Si substrates, it is possible to obtain a mirror-like surface of GaN(10-12) using an approximately 10-nm-thick AlN seed layer, which swiftly transitions from cubic AlN to hexagonal GaN.

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Zhang, Kang, Tai Ping Lu i Shu Ti Li. "Influence of the Quality of AlN Buffer Layer on the Quality of GaN Epitaxial Layer on Silicon Substrate". Advanced Materials Research 306-307 (sierpień 2011): 201–5. http://dx.doi.org/10.4028/www.scientific.net/amr.306-307.201.

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The effect of AlN buffer layer on the quality of GaN epilayer grown on Si substrate by metalorganic chemical vapor deposition (MOCVD) has been investigated. It was found that the quality of GaN epilayer strongly related with the crystal quality of AlN buffer layer. As the full width at half maximum (FWHM) of AlN (0 0 2) plane increased from 1.23 degree to 3.41 degree, the FWHM of GaN (0 0 2) plane varied from 432 arcsec to 936 arcsec and the FWHM of GaN (1 0 2) plane varied from 677 arcsec to 1226 arcsec. Besides, more cracks formed and threading dislocation (TD) density increased. The deteriorated AlN buffer layer also led to a rougher morphology of the GaN layer, as can be seen from the root mean square (RMS) roughness of GaN layer which varied from 0.178 nm to 0.476 nm. And the morphology of AlN and the quality of GaN epilayer are not appear to be relevant due to the ruleless values of RMS roughness of AlN.

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Бессолов, В. Н., Е. В. Коненкова, С. Н. Родин, Д. С. Кибалов i В. К. Смирнов. "Образование полуполярных III-нитридных слоев на поверхности Si(100), структурированной с помощью самоформирующейся наномаски". Физика и техника полупроводников 55, nr 4 (2021): 356. http://dx.doi.org/10.21883/ftp.2021.04.50740.9562.

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The epitaxial growth of AlN and GaN layers was studied by Metalorganic Vapor Phase Epitaxy, on a Si(100) substrate, on the surface of which a V-shaped nanostructure with sub-100 nm element size (NP-Si(100)) was formed. It is shown that a corrugated surface is formed from semipolar AlN(10-11) planes with opposite "c"axes during the formation of a semipolar AlN layer at the initial stage of epitaxy. Then, during the growth of the GaN layer, the transition from the symmetric state of two semipolar AlN planes to an asymmetric state with a single orientation of the "c"-axis of the semipolar GaN(10-11) layer occurs, and the "c" direction in the growing semipolar layer coincides with the direction of the flow of N2+ ions to the silicon surface during the formation of a nanomask.

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Бессолов, В. Н., Е. В. Коненкова, С. Н. Родин, Д. С. Кибалов i В. К. Смирнов. "Образование полуполярных III-нитридных слоев на поверхности Si(100), структурированной с помощью самоформирующейся наномаски". Физика и техника полупроводников 55, nr 4 (2021): 356. http://dx.doi.org/10.21883/ftp.2021.04.50740.9562.

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The epitaxial growth of AlN and GaN layers was studied by Metalorganic Vapor Phase Epitaxy, on a Si(100) substrate, on the surface of which a V-shaped nanostructure with sub-100 nm element size (NP-Si(100)) was formed. It is shown that a corrugated surface is formed from semipolar AlN(10-11) planes with opposite "c"axes during the formation of a semipolar AlN layer at the initial stage of epitaxy. Then, during the growth of the GaN layer, the transition from the symmetric state of two semipolar AlN planes to an asymmetric state with a single orientation of the "c"-axis of the semipolar GaN(10-11) layer occurs, and the "c" direction in the growing semipolar layer coincides with the direction of the flow of N2+ ions to the silicon surface during the formation of a nanomask.

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Abgaryan, Karine, Ilya Mutigullin i Dmitriy Bazhanov. "Multiscale Computational Model of Nitride Semiconductor Nanostructures". Advanced Materials Research 560-561 (sierpień 2012): 1133–37. http://dx.doi.org/10.4028/www.scientific.net/amr.560-561.1133.

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Theoretical multiscale model of nitride semiconductor nanostructure is proposed. The model combines various computational methods such as density functional theory, molecular dynamics and kinetic Monte Carlo. As a first step of implementation of proposed approach ab initio calculations of structural and electronic properties of two different structures InN/Si and AlN/AlGaN/GaN heterostructures were carried out. In particular, the influence of oxygen on InN/Si adhesion energy was studied. AlN, GaN, AlxGa1-xN (x=0.33) spontaneous and piezoelectric polarizations as well as sheet carrier concentrations at GaN/AlGaN interface were calculated. Obtained value for sheet carrier concentration at GaN/AlGaN interface is close to experimental data.

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Кукушкин, С. А., i Ш. Ш. Шарофидинов. "Новый метод получения объемных кристаллов AlN, GaN и AlGaN с использованием гибридных подложек SiC/Si". Физика твердого тела 61, nr 12 (2019): 2338. http://dx.doi.org/10.21883/ftt.2019.12.48549.51ks.

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The paper presents the main provisions of the new method of growing bulk, with a thickness of 100 μm or more, single-crystal AlN, AlGaN and GaN films on silicon poles with a silicon carbide buffer layer with their subsequent separation from the Si substrate. The main essence of this method is the combination of the method of chloride-hydride epitaxy, which ensures high growth rates of III-nitride layers using as substrate for growth, Si substrate with a buffer layer of a nanoscale atomic SiC film. The Si substrate with a SiC layer grown by the substitution method has a number of structural, physical, and chemical features as compared to SiC layers grown on Si by standard methods. It is shown that it is this feature that makes it possible to grow on its surface thick, uncracked layers of AlN, AlGaN and GaN, followed by their simple separation from the substrate. In this work, single-crystal uncracked layers were grown: AlN up to 300 microns thick; AlGaN thickness up to 400 microns; GaN thickness up to 200 microns; GaN semipolar (112 ̅4) orientation up to 35 microns.

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CHUAH, L. S., Z. HASSAN i H. ABU HASSAN. "ELECTRICAL RESISTANCE OF CRACK-FREE GaN/AlN HETEROSTRUCTURE GROWN ON Si(111)". Journal of Nonlinear Optical Physics & Materials 17, nr 03 (wrzesień 2008): 299–304. http://dx.doi.org/10.1142/s021886350800424x.

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This paper presents the electrical resistance of crack-free n-GaN/AlN/n-Si(111) diodes in relation to the temperature of the Al effusion cell for the growth of AlN intermediate layer (348 nm thickness) using radio-frequency molecular beam epitaxy (RF-MBE). The thickness of the unintentionally doped n-type GaN thin film is in the range of 63–100 nm. Aluminium (300 nm thickness) was sputtered onto the n-type GaN through a metal mask, followed by the 100 nm thick titanium (Ti) capping layer to obtain an ohmic contact. The back contact was created on the back surface of the Si substrate by evaporating indium (In) followed by thermal annealing at 400°C. We will consider the above as a device on an n-type Si(111) substrate, where the electron current flows from the Si substrate to the n-type GaN top layer. It was found that the current–voltage (I–V) characteristics depend on the various deposition temperature of the Al effusion cell for the growth of the AlN intermediate layer. In the forward bias region, where the electrons flow from Si(111) to the GaN top layer, we observe a threshold voltage of approximately 0.5 V for turning on a high current. The order of differential resistance magnitude was nearly a constant in the voltage range of 1.0 to 3.0 V.

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Davis, Robert F., T. Gehrke, K. J. Linthicum, T. S. Zheleva, P. Rajagopal, C. A. Zorman i M. Mehregany. "Pendeo-epitaxial Growth and Characterization of GaN and related Materials on 6H-SiC(0001) and Si(111) Substrates". MRS Internet Journal of Nitride Semiconductor Research 5, S1 (2000): 49–61. http://dx.doi.org/10.1557/s1092578300004075.

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Discrete and coalesced monocrystalline GaN and AlxGa1−xN layers grown via Pendeoepitaxy (PE) [1] originated from side walls of GaN seed structures containing SiNx top masks have been grown via organometallic vapor phase deposition on GaN/AlN/6HSiC(0001) and GaN(0001)/AlN(0001)/3C-SiC(111)/Si(111) substrates. Scanning and transmission electron microscopies were used to evaluate the external microstructures and the distribution of dislocations, respectively. The dislocation densities in the PE grown films was reduced by at least five orders of magnitude relative to the initial GaN seed layers. Tilting in the coalesced GaN epilayers was observed via X-ray diffraction. A tilt of 0.2° was confined to areas of mask overgrowth; however, no tilting was observed in the material suspended above the SiC substrate. The strong, low-temperature PL band-edge peak at 3.45 eV with a FWHM of 17 meV was comparable to that observed in PE GaN films grown on 6H-SiC(0001). The band-edge in the GaN grown on AlN(0001)/SiC(111)Si(111) substrates was shifted to a lower energy by 10 meV, indicative of a greater tensile stress.

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Mahyuddin, A., A. Azrina, M. Z. Mohd Yusoff i Z. Hassan. "Fabrication and characterization of AlN metal–insulator–semiconductor grown Si substrate". Modern Physics Letters B 31, nr 33 (27.11.2017): 1750313. http://dx.doi.org/10.1142/s0217984917503134.

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An experimental investigation was conducted to explore the effect of inserting a single AlGaN interlayer between AlN epilayer and GaN/AlN heterostructures on Si (111) grown by molecular beam epitaxy (MBE). It is confirmed from the scanning electron microscopy (SEM) that the AlGaN interlayer has a remarkable effect on reducing the tensile stress and dislocation density in AlN top layer. Capacitance–voltage (C–V) measurements were conducted to study the electrical properties of AlN/GaN heterostructures. While deriving the findings through the calculation it is suggested that the AlGaN interlayer can significantly reduce the value of effective oxide charge density and total effective number of charges per unit area which are [Formula: see text] and [Formula: see text], respectively.

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23

Kim, Sang-Jo, Semi Oh, Kwang-Jae Lee, Sohyeon Kim i Kyoung-Kook Kim. "Improved Performance of GaN-Based Light-Emitting Diodes Grown on Si (111) Substrates with NH3 Growth Interruption". Micromachines 12, nr 4 (5.04.2021): 399. http://dx.doi.org/10.3390/mi12040399.

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We demonstrate the highly efficient, GaN-based, multiple-quantum-well light-emitting diodes (LEDs) grown on Si (111) substrates embedded with the AlN buffer layer using NH3 growth interruption. Analysis of the materials by the X-ray diffraction omega scan and transmission electron microscopy revealed a remarkable improvement in the crystalline quality of the GaN layer with the AlN buffer layer using NH3 growth interruption. This improvement originated from the decreased dislocation densities and coalescence-related defects of the GaN layer that arose from the increased Al migration time. The photoluminescence peak positions and Raman spectra indicate that the internal tensile strain of the GaN layer is effectively relaxed without generating cracks. The LEDs embedded with an AlN buffer layer using NH3 growth interruption at 300 mA exhibited 40.9% higher light output power than that of the reference LED embedded with the AlN buffer layer without NH3 growth interruption. These high performances are attributed to an increased radiative recombination rate owing to the low defect density and strain relaxation in the GaN epilayer.

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24

Shen, Xu-Qiang, Tokio Takahashi, Hirofumi Matsuhata, Toshihide Ide i Mitsuaki Shimizu. "Self-generated microcracks in an ultra-thin AlN/GaN superlattice interlayer and their influences on the GaN epilayer grown on Si(110) substrates by metal–organic chemical vapor deposition". CrystEngComm 17, nr 27 (2015): 5014–18. http://dx.doi.org/10.1039/c5ce00929d.

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Бессолов, В. Н., Е. В. Коненкова i С. Н. Родин. "Начальные стадии роста слоя GaN(11\=22) на наноструктурированной подложке Si(113)". Физика и техника полупроводников 57, nr 1 (2023): 3. http://dx.doi.org/10.21883/ftp.2023.01.54923.3994.

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Методом растровой электронной микроскопии изучались начальные стадии формирования полуполярного GaN(1122) слоя при эпитаксии из металлоорганических соединений на подложках Si(113), на поверхности которых сформированы U-образные канавки с размером элементов <100 нм (подложка-NP-Si(113)). Установлено, что NP-Si(113) подложки с буферным слоем AlN стимулируют формирование островков, ограненных плоскостями m-GaN, c-GaN. Показано, что наблюдается преимущественный рост грани m-GaN по сравнению с c-GaN. Экспериментальные результаты соответствуют принципу отбора Гиббса--Кюри--Вульфа, но с учетом упругих напряжений в плоскости c-GaN. Ключевые слова: полуполярный нитрид галлия, нано-структурированная подложка, кремний.

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26

Arifin, Pepen, Heri Sutanto, Sugianto i Agus Subagio. "Plasma-Assisted MOCVD Growth of Non-Polar GaN and AlGaN on Si(111) Substrates Utilizing GaN-AlN Buffer Layer". Coatings 12, nr 1 (14.01.2022): 94. http://dx.doi.org/10.3390/coatings12010094.

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We report the growth of non-polar GaN and AlGaN films on Si(111) substrates by plasma-assisted metal-organic chemical vapor deposition (PA-MOCVD). Low-temperature growth of GaN or AlN was used as a buffer layer to overcome the lattice mismatch and thermal expansion coefficient between GaN and Si(111) and GaN’s poor wetting on Si(111). As grown, the buffer layer is amorphous, and it crystalizes during annealing to the growth temperature and then serves as a template for the growth of GaN or AlGaN. We used scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) characterization to investigate the influence of the buffer layer on crystal structure, orientation, and the morphology of GaN. We found that the GaN buffer layer is superior to the AlN buffer layer. The thickness of the GaN buffer layer played a critical role in the crystal quality and plane orientation and in reducing the cracks during the growth of GaN/Si(111) layers. The optimum GaN buffer layer thickness is around 50 nm, and by using the optimized GaN buffer layer, we investigated the growth of AlGaN with varying Al compositions. The morphology of the AlGaN films is flat and homogenous, with less than 1 nm surface roughness, and has preferred orientation in a-axis.

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Zhang, Zhenzhuo, Jing Yang, Degang Zhao, Baibin Wang, Yuheng Zhang, Feng Liang, Ping Chen, Zongshun Liu i Yuhao Ben. "The melt-back etching effect of the residual Ga in the reactor for GaN grown on (111) Si". AIP Advances 12, nr 9 (1.09.2022): 095106. http://dx.doi.org/10.1063/5.0105524.

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The reaction between gallium (Ga) and silicon (Si), termed melt-back etching, greatly deteriorates the quality of GaN grown on a Si substrate. In this paper, the mechanism of melt-back etching was investigated layer-by-layer in a GaN/AlN/Si system. It is found that the environment of the reactor plays a critical role in melt-back etching, which may happen as early as during the baking process. Drawing on experimental evidence and analyses, a two-step melt-back etching model is proposed. Finally, optimized pretreatments including an AlN precoating process and reduction in baking temperature were used to successfully solve the etching problem and verify the model.

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Liu, Wei-Sheng, Balaji Gururajan, Sui-Hua Wu, Li-Cheng Huang, Chung-Kai Chi, Yu-Lun Jiang i Hsing-Chun Kuo. "Optimal Growth Conditions for Forming c-Axis (002) Aluminum Nitride Thin Films as a Buffer Layer for Hexagonal Gallium Nitride Thin Films Produced with In Situ Continual Radio Frequency Sputtering". Micromachines 13, nr 9 (17.09.2022): 1546. http://dx.doi.org/10.3390/mi13091546.

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Aluminum nitride (AlN) thin-film materials possess a wide energy gap; thus, they are suitable for use in various optoelectronic devices. In this study, AlN thin films were deposited using radio frequency magnetron sputtering with an Al sputtering target and N2 as the reactive gas. The N2 working gas flow rate was varied among 20, 30, and 40 sccm to optimize the AlN thin film growth. The optimal AlN thin film was produced with 40 sccm N2 flow at 500 W under 100% N2 gas and at 600 °C. The films were studied using X-ray diffraction and had (002) phase orientation. X-ray photoelectron spectroscopy was used to determine the atomic content of the optimal film to be Al, 32%; N, 52%; and O, 12% at 100 nm beneath the surface of the thin film. The film was also investigated through atomic force microscopy and had a root mean square roughness of 2.57 nm and a hardness of 76.21 GPa. Finally, in situ continual sputtering was used to produce a gallium nitride (GaN) layer on Si with the AlN thin film as a buffer layer. The AlN thin films investigated in this study have excellent material properties, and the proposed process could be a less expensive method of growing high-quality GaN thin films for various applications in GaN-based power transistors and Si integrated circuits.

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Xie, Hanlin, Zhihong Liu, Wenrui Hu, Yu Gao, Hui Teng Tan, Kenneth E. Lee, Yong-Xin Guo, Jincheng Zhang, Yue Hao i Geok Ing Ng. "AlN/GaN MISHEMTs on Si with in-situ SiN as a gate dielectric for power amplifiers in mobile SoCs". Applied Physics Express 15, nr 1 (22.12.2021): 016503. http://dx.doi.org/10.35848/1882-0786/ac428b.

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Abstract AlN/GaN metal–insulator–semiconductor high electron mobility transistors (MISHEMTs) on silicon substrate using in situ SiN as gate dielectric were fabricated and their RF power performance at mobile system-on-chip (SoC) compatible voltages was measured. At a mobile SoC-compatible supply voltage of V d = 3.5 V/5 V, the 90 nm gate-length AlN/GaN MISHEMTs showed a maximum power-added efficiency of 62%/58%, a maximum output power density (P outmax) of 0.44 W mm−1/0.84 W mm−1 and a linear gain of 20 dB/19 dB at the frequency of 5 GHz. These results suggest that the in situ-SiN/AlN/GaN-on-Si MISHEMTs are promising for RF power amplifiers in 5G mobile SoC applications.

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30

Wang, Wenliang, Yunhao Lin, Yuan Li, Xiaochan Li, Liegen Huang, Yulin Zheng, Zhiting Lin, Haiyan Wang i Guoqiang Li. "High-efficiency vertical-structure GaN-based light-emitting diodes on Si substrates". Journal of Materials Chemistry C 6, nr 7 (2018): 1642–50. http://dx.doi.org/10.1039/c7tc04478j.

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High-quality GaN-based light-emitting diode (LED) wafers have been grown on Si substrates by metal–organic chemical vapor deposition by designing epitaxial structures with AlN/Al_0.24Ga_0.76N buffer layers and a three-dimensional (3D) GaN layer.

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31

Tiwari, Ashutosh, M. Park, C. Jin, H. Wang, D. Kumar i J. Narayan. "Epitaxial growth of ZnO films on Si(111)". Journal of Materials Research 17, nr 10 (październik 2002): 2480–83. http://dx.doi.org/10.1557/jmr.2002.0361.

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In this paper, we report the growth of ZnO films on silicon substrates using a pulsed laser deposition technique. These films were deposited on Si(111) directly as well as by using thin buffer layers of AlN and GaN. All the films were found to have c-axis-preferred orientation aligned with normal to the substrate. Films with AlN and GaN buffer layers were epitaxial with preferred in-plane orientation, while those directly grown on Si(111) were found to have random in-plane orientation. A decrease in the frequency of the Raman mode and a red shift of the band-edge photoluminescence peak due to the presence of tensile strain in the film, was observed. Various possible sources for the observed biaxial strain are discussed.

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32

CHUAH, L. S., Z. HASSAN i H. ABU HASSAN. "INFLUENCE OF Al MONOLAYERS ON THE PROPERTIES OF AlN LAYERS ON Si (111)". Surface Review and Letters 16, nr 01 (luty 2009): 99–103. http://dx.doi.org/10.1142/s0218625x09012354.

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High-quality aluminum nitride ( AlN ) layers with full width at half maximum (FWHM) values of 11 arcmin were grown by plasma-assisted molecular-beam epitaxy on Si (111) substrates. AlN nucleation layers are being investigated for the growth of GaN on Si . Growth using AlN buffer layers leads to Al -polar films, with surfaces strongly dependent on the flux conditions used. Flat surfaces can be obtained by growing as Al -rich as possible, although Al droplets tend to form. Before starting the AlN growth, a few monolayers of Al are deposited on the substrate to avoid the formation of Si 3 N 4. X-ray diffraction (XRD) techniques were employed to determine the surface and structural quality of the layers. XRD revealed that monocrystalline AlN was obtained. Best AlN films were obtained at high substrate temperatures (875°C) and III/V ratios close to stoichiometry.

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33

Roshko, Alexana, Matt Brubaker, Paul Blanchard, Todd Harvey i Kris Bertness. "Selective Area Growth and Structural Characterization of GaN Nanostructures on Si(111) Substrates". Crystals 8, nr 9 (16.09.2018): 366. http://dx.doi.org/10.3390/cryst8090366.

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Selective area growth (SAG) of GaN nanowires and nanowalls on Si(111) substrates with AlN and GaN buffer layers grown by plasma-assisted molecular beam epitaxy was studied. For N-polar samples filling of SAG features increased with decreasing lattice mismatch between the SAG and buffer. Defects related to Al–Si eutectic formation were observed in all samples, irrespective of lattice mismatch and buffer layer polarity. Eutectic related defects in the Si surface caused voids in N-polar samples, but not in metal-polar samples. Likewise, inversion domains were present in N-polar, but not metal-polar samples. The morphology of Ga-polar GaN SAG on nitride buffered Si(111) was similar to that of homoepitaxial GaN SAG.

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MOHD YUSOFF, M. Z., Z. HASSAN, C. W. CHIN, H. ABU HASSAN, M. J. ABDULLAH, N. N. MOHAMMAD, M. A. AHMAD i Y. YUSOF. "THE STUDY OF Al0.29Ga0.71N-BASED SCHOTTKY PHOTODIODES GROWN ON SILICON BY PLASMA-ASSISTED MOLECULAR BEAM EPITAXY". Modern Physics Letters B 27, nr 12 (22.04.2013): 1350085. http://dx.doi.org/10.1142/s0217984913500851.

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In this paper, the growth and characterization of epitaxial Al 0.29 Ga 0.71 N grown on Si (111) by RF-plasma assisted molecular beam epitaxy (MBE) are described. The Al mole fraction was derived from the HR-XRD symmetric rocking curve (RC) ω/2θ scans of (0002) plane as x = 0.29. PL spectrum of sample has shown sharp and intense band edge emission of GaN without the existence of yellow emission band, showing that it is comparable in crystal quality of the sample when compared with previous reports. From the Raman measurement of as-grown Al 0.29 Ga 0.71 N layer on GaN / AlN / Si sample. We found that the dominant E 2 (high) phonon mode of GaN appears at 572.7 cm-1. The E 2 (high) mode of AlN appears at 656.7 cm-1 and deviates from the standard value of 655 cm-1 for unstrained AlN . Finally, AlGaN Schottky photodiode have been fabricated and analyzed by mean of electrical characterization, using current–voltage (I–V) measurement to evaluate the performance of this device.

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Blumberg, C., F. Wefers, F. J. Tegude, N. Weimann i W. Prost. "Mask-less MOVPE of arrayed n-GaN nanowires on site- and polarity-controlled AlN/Si templates". CrystEngComm 21, nr 48 (2019): 7476–88. http://dx.doi.org/10.1039/c9ce01151j.

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CHUAH, L. S., S. M. THAHAB i Z. HASSAN. "GaN ON SILICON SUBSTRATE WITH AlN BUFFER LAYER FOR UV PHOTODIODE". Journal of Nonlinear Optical Physics & Materials 21, nr 01 (marzec 2012): 1250014. http://dx.doi.org/10.1142/s0218863512500142.

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Nitrogen plasma-assisted molecular beam epitaxy (PAMBE) deposited GaN thin films on (111) n-type silicon substrate with different thickness AlN buffer layers are investigated and distinguished by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman scattering. The thickness of AlN buffer layer ranged from 200 nm to 300 nm. Besides that, the electrical characteristics of the GaN thin film for ultraviolet detecting utilizations are studied by calculating the photo current/dark current ratio on a metal-semiconductor-metal (MSM) photodiode with and without the illumination of Hg-lamp source. The devices have been tested over room temperature (RT). The photocurrent analysis, together with the study of Schottky barrier height (SBH) development, ascertain that the principal mechanism of photo transport is thermionic emission. The photocurrent value is rigorously dependent on Schottky barrier height. The GaN/AlN(200 nm)/n-Si MSM photodiode produces the highest photo/dark current ratio for the lowest strain that consists of the GaN film grown on the AlN (200 nm) buffer layer.

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Dugar, Palak, Mahesh Kumar, Shibin Krishna T. C., Neha Aggarwal i Govind Gupta. "Carrier relaxation dynamics in defect states of epitaxial GaN/AlN/Si using ultrafast transient absorption spectroscopy". RSC Advances 5, nr 102 (2015): 83969–75. http://dx.doi.org/10.1039/c5ra10877b.

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Bessolov V. N., Konenkova E. V. i Rodin S. N. "Initial stages of growth of the GaN(11\=22) layer on a nano-structured Si(113) substrate". Semiconductors 57, nr 1 (2023): 3. http://dx.doi.org/10.21883/sc.2023.01.55614.3994.

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Scanning electron microscopy was used to study of the initial stages of the formation of a semipolar GaN(1122) layer during Metalorganic Chemical Vapor Deposition on Si(113) substrates, on the surface of which U-shaped grooves with element sizes <100 nm (NP-Si(113)) were formed. It was found that NP-Si(113) substrates with a buffer AlN layer stimulate the formation of islands faceted by the planes m-GaN, c-GaN. It is shown that there is a predominant growth of the m-GaN facet in comparison with c-GaN.The experimental results correspond to the Gibbs--Curie--Wolff selection principle, but taking into account elastic stresses in the c-GaN plane. Keywords: semipolar gallium nitride, nano-structured substrate, silicon.

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Cao, X. A., S. J. Pearton, R. K. Singh, C. R. Abernathy, J. Han, R. J. Shul, D. J. Rieger i in. "Rapid Thermal Processing of Implanted GaN up to 1500°C". MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 671–77. http://dx.doi.org/10.1557/s1092578300003239.

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GaN implanted with donor(Si, S, Se, Te) or acceptor (Be, Mg, C) species was annealed at 900-1500 °C using AlN encapsulation. No redistribution was measured by SIMS for any of the dopants and effective diffusion coefficients are ≤2 × 10−13 cm2. s−1 at 1400 °C, except Be, which displays damage-enhanced diffusion at 900 °C and is immobile once the point defect concentration is removed. Activation efficiency of ∼90% is obtained for Si at 1400 °C. TEM of the implanted material shows a strong reduction in lattice disorder at 1400-1500 °C compared to previous results at 1100 °C. There is minimal interaction of the sputtered AlN with GaN under our conditions, and it is readily removed selectively with KOH.

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Song, Chunyan, Xuelin Yang, Panfeng Ji, Jun Tang, Shan Wu, Yue Xu, Ali Imran i in. "Impact of Silicon Substrate with Low Resistivity on Vertical Leakage Current in AlGaN/GaN HEMTs". Applied Sciences 9, nr 11 (11.06.2019): 2373. http://dx.doi.org/10.3390/app9112373.

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The role of low-resistivity substrate on vertical leakage current (VLC) of AlGaN/GaN-on-Si epitaxial layers has been investigated. AlGaN/GaN high-electron-mobility transistors (HEMTs) grown on both p-type and n-type Si substrates with low resistivity are applied to analyze the vertical leakage mechanisms. The activation energy (Ea) for p-type case is higher than that for n-type at 0–600 V obtained by temperature-dependent current-voltage measurements. An additional depletion region in the region of 0–400 V forms at the AlN/p-Si interface but not for AlN/n-Si. That depletion region leads to a decrease of electron injection and hence effectively reduces the VLC. While in the region of 400–600 V, the electron injection from p-Si substrate increases quickly compared to n-Si substrate, due to the occurrence of impact ionization in the p-Si substrate depletion region. The comparative results indicate that the doping type of low-resistivity substrate plays a key role for VLC.

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Piner, E. L., D. M. Keogh, J. S. Flynn i J. M. Redwing. "AlGaN/GaN High Electron Mobility Transistor Structure Design and Effects on Electrical Properties". MRS Internet Journal of Nitride Semiconductor Research 5, S1 (2000): 349–54. http://dx.doi.org/10.1557/s109257830000449x.

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We report on the effect of strain induced polarization fields in AlGaN/GaN heterostructures due to the incorporation of Si dopant ions in the lattice. By Si-doping (Al)GaN, a contraction of the wurtzite unit cell can occur leading to strain in doped AlGaN/GaN heterostructures such as high electron mobility transistors (HEMTs). In a typical modulation doped AlGaN/GaN HEMT structure, the Si-doped AlGaN supply layer is separated from the two-dimensional electron gas channel by an undoped AlGaN spacer layer. This dopant-induced strain, which is tensile, can create an additional source of charge at the AlGaN:Si/AlGaN interface. The magnitude of this strain increases as the Si doping concentration increases and the AlN mole fraction in the AlGaN decreases. Consideration of this strain should be given in AlGaN/GaN HEMT structure design.

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Pezoldt, Jörg, Rolf Grieseler, Thorsten Schupp, Donat J. As i Peter Schaaf. "Mechanical Properties of Cubic SiC, GaN and AlN Thin Films". Materials Science Forum 717-720 (maj 2012): 513–16. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.513.

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Cubic polytypes of SiC, GaN and AlN were grown on silicon by molecular beam epitaxy. The mechanical properties of the epitaxial layers were investigated by nanoindentation. For 3C-SiC grown on Si(111) and Si(100) a dependence of the mechanical properties on the surface preparation with germanium prior to the carbonization was obtained.

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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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Wośko, Mateusz, Bogdan Paszkiewicz, Andrej Vincze, Tomasz Szymański i Regina Paszkiewicz. "GaN/AlN superlattice high electron mobility transistor heterostructures on GaN/Si(111)". physica status solidi (b) 252, nr 5 (21.01.2015): 1195–200. http://dx.doi.org/10.1002/pssb.201451596.

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Hsu, Lung-Hsing, Yung-Yu Lai, Po-Tsung Tu, Catherine Langpoklakpam, Ya-Ting Chang, Yu-Wen Huang, Wen-Chung Lee i in. "Development of GaN HEMTs Fabricated on Silicon, Silicon-on-Insulator, and Engineered Substrates and the Heterogeneous Integration". Micromachines 12, nr 10 (27.09.2021): 1159. http://dx.doi.org/10.3390/mi12101159.

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GaN HEMT has attracted a lot of attention in recent years owing to its wide applications from the high-frequency power amplifier to the high voltage devices used in power electronic systems. Development of GaN HEMT on Si-based substrate is currently the main focus of the industry to reduce the cost as well as to integrate GaN with Si-based components. However, the direct growth of GaN on Si has the challenge of high defect density that compromises the performance, reliability, and yield. Defects are typically nucleated at the GaN/Si heterointerface due to both lattice and thermal mismatches between GaN and Si. In this article, we will review the current status of GaN on Si in terms of epitaxy and device performances in high frequency and high-power applications. Recently, different substrate structures including silicon-on-insulator (SOI) and engineered poly-AlN (QST®) are introduced to enhance the epitaxy quality by reducing the mismatches. We will discuss the development and potential benefit of these novel substrates. Moreover, SOI may provide a path to enable the integration of GaN with Si CMOS. Finally, the recent development of 3D hetero-integration technology to combine GaN technology and CMOS is also illustrated.

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Lee, Jae-Hoon, i Jung-Hee Lee. "Growth and Device Performance of AlGaN/GaN Heterostructure with AlSiC Precoverage on Silicon Substrate". Advances in Materials Science and Engineering 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/290646.

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A crack-free AlGaN/GaN heterostructure was grown on 4-inch Si (111) substrate with initial dot-like AlSiC precoverage layer. It is believed that introducing the AlSiC layer between AlN wetting layer and Si substrate is more effective in obtaining a compressively stressed film growth than conventional Al precoverage on Si surface. The metal semiconductor field effect transistor (MESFET), fabricated on the AlGaN/GaN heterostructure grown with the AlSiC layer, exhibited normally on characteristics, such as threshold voltage of −2.3 V, maximum drain current of 370 mA/mm, and transconductance of 124 mS/mm.

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Bolshakov, Alexey D., Alexey M. Mozharov, Georgiy A. Sapunov, Igor V. Shtrom, Nickolay V. Sibirev, Vladimir V. Fedorov, Evgeniy V. Ubyivovk, Maria Tchernycheva, George E. Cirlin i Ivan S. Mukhin. "Dopant-stimulated growth of GaN nanotube-like nanostructures on Si(111) by molecular beam epitaxy". Beilstein Journal of Nanotechnology 9 (15.01.2018): 146–54. http://dx.doi.org/10.3762/bjnano.9.17.

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In this paper we study growth of quasi-one-dimensional GaN nanowires (NWs) and nanotube (NT)-like nanostructures on Si(111) substrates covered with a thin AlN layer grown by means of plasma-assisted molecular beam epitaxy. In the first part of our study we investigate the influence of the growth parameters on the geometrical properties of the GaN NW arrays. First, we find that the annealing procedure carried out prior to deposition of the AlN buffer affects the elongation rate and the surface density of the wires. It has been experimentally demonstrated that the NW elongation rate and the surface density drastically depend on the substrate growth temperature, where 800 °C corresponds to the maximum elongation rate of the NWs. In the second part of the study, we introduce a new dopant-stimulated method for GaN nanotube-like nanostructure synthesis using a high-intensity Si flux. Transmission electron microscopy was used to investigate the morphological features of the GaN nanostructures. The synthesized structures have a hexagonal cross-section and possess high crystal quality. We propose a theoretical model of the novel nanostructure formation which includes the role of the dopant Si. Some of the Si-doped samples were studied with the photoluminescence (PL) technique. The analysis of the PL spectra shows that the highest value of donor concentration in the nanostructures exceeds 5∙1019 cm−3.

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Ene, Vladimir Lucian, Doru Dinescu, Nikolay Djourelov, Iulia Zai, Bogdan Stefan Vasile, Andreea Bianca Serban, Victor Leca i Ecaterina Andronescu. "Defect Structure Determination of GaN Films in GaN/AlN/Si Heterostructures by HR-TEM, XRD, and Slow Positrons Experiments". Nanomaterials 10, nr 2 (23.01.2020): 197. http://dx.doi.org/10.3390/nano10020197.

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The present article evaluates, in qualitative and quantitative manners, the characteristics (i.e., thickness of layers, crystal structures, growth orientation, elemental diffusion depths, edge, and screw dislocation densities), within two GaN/AlN/Si heterostructures, that alter their efficiencies as positron moderators. The structure of the GaN film, AlN buffer layer, substrate, and their growth relationships were determined through high-resolution transmission electron microscopy (HR-TEM). Data resulting from high-resolution X-ray diffraction (HR-XRD) was mathematically modeled to extract dislocation densities and correlation lengths in the GaN film. Positron depth profiling was evaluated through an experimental Doppler broadening spectroscopy (DBS) study, in order to quantify the effective positron diffusion length. The differences in values for both edge ( ρ d e ) and screw ( ρ d s ) dislocation densities, and correlation lengths (Le, Ls) found in the 690 nm GaN film, were associated with the better effective positron diffusion length (Leff) of L eff GaN 2 = 43 ± 6 nm.

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Mohd Yusoff, M. Z., A. Mahyuddin, Z. Hassan, Y. Yusof, M. A. Ahmad, C. W. Chin, H. Abu Hassan i M. J. Abdullah. "Plasma-assisted MBE growth of AlN/GaN/AlN heterostructures on Si (111) substrate". Superlattices and Microstructures 60 (sierpień 2013): 500–507. http://dx.doi.org/10.1016/j.spmi.2013.05.034.

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Sánchez, A. M., F. J. Pacheco, S. I. Molina, P. Ruterana, F. Calle, T. A. Palacios, M. A. Sánchez-Garcı́a, E. Calleja i R. Garcı́a. "AlN buffer layer thickness influence on inversion domains in GaN/AlN/Si(111)". Materials Science and Engineering: B 93, nr 1-3 (maj 2002): 181–84. http://dx.doi.org/10.1016/s0921-5107(02)00030-2.

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