Дисертації з теми "Field-effect doping"
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1
Nukala, Prathyusha. "Development of Silicon Nanowire Field Effect Transistors." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc103364/.
Повний текст джерелаАнотація:
An economically reliable technique for the synthesis of silicon nanowire was developed using silicon chloride as source material. The 30-40 micron long nanowires were found to have diameters ranging from 40 – 100 nm. An amorphous oxide shell covered the nanowires, post-growth. Raman spectroscopy confirmed the composition of the shell to be silicon-dioxide. Photoluminescence measurements of the as-grown nanowires showed green emission, attributed to the presence of the oxide shell. Etching of the oxide shell was found to decrease the intensity of green emission. n-type doping of the silicon nanowires was achieved using antimony as the dopant. The maximum dopant concentration was achieved by post-growth diffusion. Intrinsic nanowire parameters were determined by implementation of the as-grown and antimony doped silicon nanowires in field effect transistor configuration.
2
Liu, Shiyi. "Understanding Doped Organic Field-Effect Transistors." Kent State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=kent1574127009556301.
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3
Randell, Heather Eve. "Applications of stress from boron doping and other challenges in silicon technology." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0010292.
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4
Periwal, Priyanka. "VLS growth and characterization of axial Si-SiGe heterostructured nanowire for tunnel field effect transistors." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT045.
Повний текст джерелаАнотація:
L'augmentation des performances des circuits intégrés s'est effectué durant les trentes dernières années par la miniaturisation du composant clé à savoir le transistor MOSFET. Cette augmentation de la densité d'intégration se heurte aujourd'hui à plusieurs verrous, notamment celui de la puissance consommée qui devient colossale. Il devient alors nécessaire de travailler sur de nouveaux composants, les transistors à effet tunnel, où les porteurs sont injectés par effet tunnel bande à bande permettant de limiter considérablement la puissance consommée en statique. Les nanofils semiconducteurs sont de bons candidats pour être intégrés comme canaux de ces nouveaux composants de part la possibilité de moduler leur gap et leur conductivité au cours de la croissance. Dans ce contexte, cette thèse traite de la croissance d'hétérostructures axiales Si/Si1-xGex élaborés par croissance VLS par RP-CVD. Tout d'abord, nous identifions les conditions de croissance pour réaliser des interface Si/Si1-xGex et Si1-xGex/Si abruptes. Les deux heterointerfaces sont toujours asymétrique quelle que soit la concentration en Ge ou le diamètre des nanofils ou des conditions de croissance. Deuxièmement, nous étudions les problématiques impliquées par l'ajout d'atomes dopants. Nous discutons de l'influence des paramètres de croissance (le rapport flux de gaz (Si / Ge), et la pression partielle de dopants) sur la morphologie des nanofils et la concentration de porteurs. Grâce à cette étude, nous avons été capable de faire croitre des hétérojonctions P-I-N. Troisièmement, nous présentons une technique basée sur la microscopie à sonde locale pour caractériser les hétérojonctionsAfter more than 30 years of successful scaling of MOSFET for increasing the performance and packing density, several limitations to further performance enhancements are now arising, power dissipation is one of the most important one. As scaling continues, there is a need to develop alternative devices with subthreshold slope below 60 mV/decade. In particular, tunnel field effect transistors, where the carriers are injected by quantum band to band tunneling mechanism can be promising candidate for low-power design. But, such devices require the implementation of peculiar architectures like axial heterostructured nanowires with abrupt interface. Using Au catalyzed vapor-liquid-solid synthesis of nanowires, reservoir effect restrains the formation of sharp junctions. In this context, this thesis addresses the growth of axial Si and Si1-xGex heterostructured nanowire with controlled interfacial abruptness and controlled doping using Au catalyzed VLS growth by RP-CVD. Firstly, we identify the growth conditions to realize sharp Si/Si1-xGex and Si1-xGex/Si interfacial abruptness. The two heterointerfaces are always asymmetric irrespective of the Ge concentration or nanowire diameter or growth conditions. Secondly, we study the problematics involved by the addition of dopant atoms and focus on the different approaches to realize taper free NWs. We discuss the influence of growth parameters (gas fluxes (Si or Ge), dopant ratio and pressure) on NW morphology and carrier concentration. With our growth process, we could successfully grow p-I, n-I, p-n, p-i-n type junctions in NWs. Thirdly, we present scanning probe microscopy to be a potential tool to delineate doped and hetero junctions in these as-grown nanowires. Finally, we will integrate the p-i-n junction in the NW in omega gate configuration
5
Sundararajan, Abhishek. "A STUDY ON ATOMICALLY THIN ULTRA SHORT CONDUCTING CHANNELS, BREAKDOWN, AND ENVIRONMENTAL EFFECTS." UKnowledge, 2015. http://uknowledge.uky.edu/physastron_etds/27.
Повний текст джерелаАнотація:
We have developed a novel method of producing ultra-short channel graphene field effect devices on SiO2 substrates and have studied their electrical transport properties. A nonlinear current behavior is observed coupled with a quasi-saturation effect. An analytical model is developed to explain this behavior using ballistic transport, where the charge carriers experience minimal scattering. We also observe multilevel resistive switching after the device is electrically stressed. In addition, we have studied the evolution of the electrical transport properties of few-layer graphene during electrical breakdown. We are able to significantly increase the time scale of break junction formation, and we are able to observe changes occurring close to breakdown regime. A decrease in conductivity along with p−type doping of the graphene channel is observed as the device is broken. The addition of structural defects generated by thermal stress caused by high current densities is attributed to the observed evolution of electrical properties during the process of breakdown. We have also studied the effects of the local environment on graphene devices. We encapsulate graphene with poly(methyl methacrylate) (PMMA) polymer and study the electrical transport through in situ measurements. We have observed an overall decrease in doping level after low-temperature annealing in dry-nitrogen, indicating that the solvent in the polymer plays an important role in doping. For few-layer encapsulated graphene devices, we observe stable n−doping. Applying the solvent onto encapsulated devices demonstrates enhanced hysteretic switching between p and n−doped states.
6
Krishnan, Bharat. "DEVELOPMENT OF SIMULATION FRAMEWORK FOR THE ANALYSIS OF NON-IDEAL EFFECTS IN DOPING PROFILE MEASUREMENT USING CAPACITANCE ? VOLTAGE TECHNIQUE." MSSTATE, 2005. http://sun.library.msstate.edu/ETD-db/theses/available/etd-04082005-092339/.
Повний текст джерелаАнотація:
Silicon Carbide devices are proving to be most promising for high power and high-temperature application in recent times. Efficient and accurate characterization of the device characteristics is key to the fabrication of high quality devices and reproduction of the quality of the devices fabricated. Capacitance-Voltage profiling is one of the most commonly used techniques to measure the doping profiles of semiconductors. However, interpretation of C-V profiling in the presence of traps in the material becomes complicated. Various complications arising from compensation between donors and acceptors, partial ionization of dopants and presence of deep level impurities could yield anomalous measured profile. Silicon Carbide being a wide bandgap semiconductor, many impurities commonly found such as Boron and Aluminum are not completely ionized at Room temperature. This leads to complications in calculating doping profiles when the trap levels are deeper. Other complications arising due to series resistance effect and diode edge effect may also affect the measured profile. Accounting for these complications may be difficult by mere observation of the measured profile. Simulation can be an excellent tool to extract parameters of interest from experimental results that are influenced by non-ideal effects. Fitting of the experimentally obtained data with simulated profile using specific models may be a useful technique to quantitatively account for the deviations from the actual profiles.
7
Shin, Nara [Verfasser], Karl [Gutachter] Leo, Stefan [Gutachter] Mannsfeld, and Sebastian [Gutachter] Reineke. "Enhancement of n-channel Organic Field-Effect Transistor Performance through Surface Doping and Modification of the Gate Oxide by Aminosilanes / Nara Shin ; Gutachter: Karl Leo, Stefan Mannsfeld, Sebastian Reineke." Dresden : Technische Universität Dresden, 2019. http://d-nb.info/1230578196/34.
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Yoo, Kyung-Dong. "Two-dimensional dopant profiling for shallow junctions by TEM and AFM." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342122.
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Winkler, Felix [Verfasser], Johann W. [Gutachter] Bartha, and Christian [Gutachter] Wenger. "Through Silicon Via Field-Effect Transistor with Hafnia-based Ferroelectrics and the Doping of Silicon by Gallium Implantation Utilizing a Focused Ion Beam System / Felix Winkler ; Gutachter: Johann W. Bartha, Christian Wenger." Dresden : Technische Universität Dresden, 2020. http://d-nb.info/122731227X/34.
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10
Wehrfritz, Peter. "Herstellung und Charakterisierung von Feldeffekttransistoren mit epitaktischem Graphen." Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-172853.
Повний текст джерелаАнотація:
Als Graphen bezeichnet man eine einzelne freistehende Lage des Schichtkristalls Graphit. Im Gegensatz zur mechanischen Isolation von Graphit bietet die Züchtung auf Siliziumkarbid eine Methode zur großflächigen Herstellung von Graphen. Aufgrund der besonderen physikalischen Eigenschaften werden für Graphen viele verschieden Einsatzmöglichkeiten in diversen Bereichen prognostiziert. Mit seiner hohen Ladungsträgerbeweglichkeit ist Graphen besonders als Kanalmaterial für Feldeffekttransistoren (FET) interessant. Allerdings muss hierfür unter anderem ein geeignetes FET-Isolatormaterial gefunden werden.
In dieser Arbeit wird eine detaillierte, theoretische Beschreibung der Graphen-FETs vorgestellt, die es erlaubt die steuerspannungsabhängige Hall-Konstante zu berechnen. Mit der dadurch möglichen Analyse können wichtige Kenngrößen, wie z. B. die Grenzflächenzustandsdichte des Materialsystems bestimmt werden. Außerdem wurden zwei Methoden zur Isolatorabscheidung auf Graphen untersucht. Siliziumnitrid, welches mittels plasmaangeregter Gasphasenabscheidung aufgetragen wurde, zeichnet sich durch seine n-dotierende Eigenschaft aus. Damit ist es vor allem für quasi-freistehendes Graphen auf Siliziumkarbid interessant. Bei der zweiten Methode handelt es sich um einen atomaren Schichtabscheidungsprozess, der ohne eine Saatschicht auskommt. An beiden Graphen- Isolator-Kombinationen wurde die neue Charakterisierung mittels der Hall-Datenanalyse angewandt.
11
Ingram, Ian David Victor. "New materials and processes for flexible nanoelectronics." Thesis, University of Manchester, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588129.
Повний текст джерелаАнотація:
Planar electronic devices represent an attractive approach towards roll-to-roll printed electronics without the need for the sequential, precisely aligned, patterning steps inherent in the fabrication of conventional ‘3D’ electronic devices. Self-switching diodes (SSDs) and in-plane-gate field-effect transistors (IPG-FETs) can be patterned using a single process into a substrate precoated with semiconductor.These devices function in depletion mode, requiring the semiconductor to be doped in order for the devices to function. To achieve this, a reliable and controllable method was developed for doping organic semiconducting polymers by the immersion of optimally deposited films in a solution of dopant. The process was shown to apply both semicrystalline and air-stable, amorphous materials indicating that the approach is broadly applicable to a wide range of organic semiconductors.Simultaneously with the development of the doping protocol specialised hot-embossing equipment was designed and constructed and a high-yielding method of patterning the structures of IPG-FETs and SSDs was arrived at. This method allowed for consistent and reliable patterning of features with a minimum line-width of 200nm.Following the development of these doping and patterning processes these were combined to fabricate controllably doped, functioning planar devices. SSDs showed true zero-threshold rectification behaviour with no observed breakdown in the reverse direction up to 100 V. IPG-FETs showed switching behaviour in response to an applied gate potential and were largely free of detectable gate leakage current, verifying the quality of the patterning process.Furthermore, high-performance semiconducting polymer PAAD was synthesised and characterised in field-effect transistors as steps towards its use in planar electronic devices. It was also shown that this material could be doped using the developed immersion doping protocol and that this protocol was compatible with top-gated device architectures and the use of fluoropolymer CYTOP as a dielectric.
12
Kleemann, Hans. "Organic Electronic Devices - Fundamentals, Applications, and Novel Concepts." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-105059.
Повний текст джерелаАнотація:
This work addresses two substantial problems of organic electronic devices: the controllability and adjustability of performance, and the integration using scalable, high resolution patterning techniques for planar thin-film transistors and novel vertical transistor devices. Both problems are of particular importance for the success of transparent and flexible organic electronics in the future.
To begin with, the static behavior in molecular doped organic pin-diodes is investigated. This allows to deduce important diode parameters such as the depletion capacitance, the number of active dopant states, and the breakdown field. Applying this knowledge, organic pin-diodes are designed for ultra-high-frequency applications and a cut-off-frequency of up to 1GHz can be achieved using optimized parameters for device geometry, layer thickness, and dopant concentration.
The second part of this work is devoted to organic thin-film transistors, high resolution patterning techniques, as well as novel vertical transistor concepts. In particular, fluorine based photo-lithography, a high resolution patterning technique compatible to organic semiconductors, is introduced fielding the integration of organic thin-film transistors under ambient conditions. However, as it will be shown, horizontal organic thin-film transistors are substantially limited in their performance by charge carrier injection. Hence, down-scaling is inappropriate to enlarge the transconductance of such transistors. To overcome this drawback, a novel vertical thin-film transistor concept with a vertical channel length of ∼50nm is realized using fluorine based photo-lithography. These vertical devices can surpass the performance of planar transistors and hence are prospective candidates for future integration in complex electronic circuits.
13
Procházka, Pavel. "Příprava grafenu a výzkum jeho fyzikálních vlastností." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-371775.
Повний текст джерелаАнотація:
This doctoral thesis is focused on the preparation of graphene layers by Chemical Vapor Deposition (CVD) and their utilization for fabrication and characterization of field effect transistors. The theoretical part of the thesis deals with different methods of graphene production and measurement of its transport properties. In the first part of the experimental section the growth of polycrystalline graphene and individual graphene crystals with sizes up to 300 m is investigated. Further, graphene layer was also grown on an atomically flat copper foils, which were fabricated in order to achieve the growth of graphene of higher quality. Subsequently, the transport properties of field effect transistors produced from the grown layers were measured. The last two chapters deal with a doping of graphene layer by gallium atoms and X-ray radiation. Whereas the deposition of gallium atoms on the graphene surface causes chemical doping of graphene layer by charge transfer, X-ray irradiation of graphene field effect transistors induces the ionization of positively charged defects in dielectrics, which electrostatically dope a graphene layer.
14
Chicot, Gauthier. "Effet de champs dans le diamant dopé au bore." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-01062250.
Повний текст джерелаАнотація:
Alors que la demande en électronique haute puissance et haute fréquence ne fait qu'augmenter, les semi-conducteurs classiques montrent leurs limites. Des approches basées soit sur des nouvelles architectures ou sur des matériaux à large bande interdite devraient permettre de les dépasser. Le diamant, avec ses propriétés exceptionnelles, semble être le semi-conducteur ultime pour répondre à ces attentes. Néanmoins, il souffre aussi de certaines limitations, en particulier d'une forte énergie d'ionisation du dopant de type p (bore) qui se traduit par une faible concentration de porteurs libres à la température ambiante. Des solutions innovantes s'appuyant sur un gaz 2D et /ou l'effet de champ ont été imaginées pour résoudre ce problème. Ce travail est axé sur deux de ces solutions : i) le diamant delta dopé au bore qui consiste en une couche fortement dopée entre deux couches intrinsèques, afin d'obtenir une conduction combinant une grande mobilité avec une grande concentration de porteurs et ii) le transistor à effet de champ métal oxide semiconducteur( MOSFET ), où l'état " on " et l'état " off " du canal sont obtenus grâce au contrôle électrostatique de la courbure de bandes à l' interface de diamant/oxyde. Pour ces deux structures, beaucoup de défis technologiques doivent être surmontés avant de pouvoir fabriquer un transistor. La dépendance en température de la densité surfacique de trous et de la mobilité de plusieurs couche de diamant delta dopées au bore a été étudiée expérimentalement et théoriquement sur une large gamme de température (6 K
15
Ogier, Jean-Luc. "Optimisation de structures et de technologies pour la réalisation de drain-source de transistors MOS submicroniques." Université Joseph Fourier (Grenoble), 1993. http://www.theses.fr/1993GRE10167.
Повний текст джерелаАнотація:
Afin de reduire les effets de canaux courts et de porteurs chauds, nous avons etudie differentes solutions technologiques concernant les drain/source de transistors metal oxyde silicium (mos) submicroniques. Cette etude a ete realisee dans le cadre de filieres cmos (mos complementaires) submicroniques (0. 7-0. 5-0. 35 micron). Concernant le transistor nmos, notre etude vise a reduire les phenomenes de degradations par porteurs chauds qui affectent la fiabilite du dispositif. Nous nous interessons uniquement a la partie faiblement dopee du drain (ldd). Nous presentons dans un premier temps les resultats concernant la comparaison ldd arsenic/phosphore pour une technologie 0. 5 micron. Nous abordons ensuite l'etude d'une structure ldd implantee avec un fort angle de tilt dans le cadre d'un procede 0. 35 micron. Pour le transistor pmos, nous presentons differents essais visant a reduire la profondeur des jonctions de drain/source et nous traitons l'aspect degradation par porteurs chauds avec l'etude de la structure ldd pmos. Cette etude s'est concretisee par l'adoption de choix technologiques sur les filieres du cnet et de ses partenaires (matra-mhs, centre commun cnet-st)
16
Hamidi, Sakr Amer. "Thin films of polythiophenes oriented by epitaxy and high-temperature rubbing : correlations with optical, charge-transport and thermoelectrical properties." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE019.
Повний текст джерелаАнотація:
Le but de cette thèse est d'étudier l'effet de l’alignement et le contrôle de la morphologie de films minces de polythiophènes et de les corréler avec les propriétés optiques, de transport de charges et thermoélectriques. Puisque les polymères semiconducteurs sont intrinsèquement anisotropes, il est essentiel de les aligner afin de comprendre leur propriétés. Cette étude a été réalisée en employant deux techniques qui ont permises d’obtenir des films minces orientés. Le brossage à haute température et la cristallisation épitaxiale directionnelle (CED) ont conduit à des films de polythiophène hautement orientés avec des paramètres d'ordre allant jusqu'à 0.87 et des taux de crystallinité jusqu'à 65%. La technique de brossage nous a permis de contrôler avec précision les tailles des domaines cristallins dans des films de P3HT brossés. Par cette méthode, nous avons pu également déterminer les températures de fusion à l'équilibre de différents poly(3-alkyl-thiophène). Nous avons appris que la largeur de bande du couplage excitonique W dépend des dimensions des cristaux dans les films minces brossés. Cette étude à aussi montrer l’importance de la planarité des chaînes pontant les domaines cristallins à travers les zones amorphes sur les propriétés de transport de charges. Nous avons également mis en évidence la morphologie particulière du poly (3-butylthiophène) (P3BT) et le rôle des groupements butyles. La méthode de cristallisation epitaxialle a été utilisée pour orienter des films de poly(3-dioctylphenyl-thiophène) (PDOPT). Nous avons examiné l'effet de la masse moléculaire du PDOPT sur le degré de cristallinité et l'alignement. Ceci nous a permis de proposer un modèle structural montrant l’absence de pi-stacking dans ce polythiophène. Finalement, nous proposons une méthode en deux étapes d’élaboration de films minces conducteurs alignés. Le brossage des films puis le dopage des polymères semiconducteurs de type-P a permis d’obtenir des propriétés thermoélectriques anisotropes améliorées.Cette thèse démontre l'importance du contrôle de la morphologie et de l'alignement des polymères semiconducteurs et conducteurs pour comprendre leurs propriétés fortement anisotropesThe aim of this thesis is to study the effect of alignment and morphological control on polythiophene thin films and to correlate this control with the optical, charge transport and thermoelectric properties. Since semiconducting polymers are inherently anisotropic by nature, studying these polymers in the aligned state was essential to understand their properties. This study could be achieved by employing two techniques that are successful in orienting polymers in thin films. High-temperature rubbing (HTR) along with directional epitaxial crystallization (DEC) produced highly oriented polythiophene thin films with order parameters reaching 0.87 and crystallinities up to 65%. HTR was a successful method to control crystal sizes in rubbed poly(3-hexyl-thiophene) P3HT films. By this method, the equilibrium melting temperatures of other poly(3-alkyl-thiophene) P3ATs were calculated. We learned that the free excitonic bandwidth depends on the crystal dimensions in the rubbed thin films. We also learned that the planarity of tie-chains linking consecutive crystalline domains plays a very important role in field-effect mobility. We also discuss the peculiar morphology of poly(3-butyl-thiophene) (P3BT) and the role of the butyl side groups. Then DEC method was proposed to orient poly(3-dioctylphenyl-thiophene) (PDOPT) thin films. We examined the effect of molecular weight of PDOPT on the level of crystallinity and alignment. Consequently, this relation provided fundamental information that helped us refine the crystal structure of PDOPT. Finally, a versatile method to produce highly aligned conducting polymers was proposed. HTR followed by P-type doping proved to be an excellent way to produce highly aligned conducting thin films with enhanced thermoelectric properties. This thesis brings value to the importance of morphology control and the alignment of semiconducting thin films to understand the various properties of these highly anisotropic systems
17
Fromm, Felix Jonathan. "Raman-Spektroskopie an epitaktischem Graphen auf Siliziumkarbid (0001)." Doctoral thesis, Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-165167.
Повний текст джерелаАнотація:
Die vorliegende Arbeit behandelt die Charakterisierung von epitaktischem Graphen auf Siliziumkarbid (0001) mittels Raman-Spektroskopie. Nach der Einführung theoretischer sowie experimenteller Grundlagen werden das Wachstum von Graphen auf Siliziumkarbid (SiC) behandelt und die untersuchten Materialsysteme vorgestellt.
Es wird gezeigt, dass das Raman-Spektrum von epitaktischem Graphen auf SiC (0001) neben den Phononenmoden des Graphens und des Substrats weitere Signale beinhaltet, welche der intrinsischen Grenzflächenschicht, dem Buffer-Layer, zwischen Graphen und SiC zugeordnet werden können. Das Raman-Spektrum dieser Grenzflächenschicht kann als Abbild der phononischen Zustandsdichte interpretiert werden. Fortführend werden verspannungsinduzierte Änderungen der Phononenenergien der G- und 2D-Linie im Raman-Spektrum von Graphen untersucht. Dabei werden starke Variationen des Verspannungszustands beobachtet, welche mit der Topographie der SiC-Oberfläche korreliert werden können und erlauben, Rückschlüsse auf Wachstumsmechanismen zu ziehen. Die Entwicklung einer neuen Messmethode, bei der das Raman-Spektrum von Graphen durch das SiC-Substrat aufgenommen wird, ermöglicht die detektierte Raman-Intensität um über eine Größenordnung zu erhöhen. Damit wird die Raman-spektroskopische Charakterisierung eines Graphen-Feldeffekttransistors mit top gate ermöglicht und ein umfassendes Bild des Einflusses der Ladungsträgerkonzentration und der Verspannung auf die Positionen der G- und 2D-Raman-Linien von quasifreistehendem Graphen auf SiC erarbeitet.
18
Fiori, Alexandre. "Nouvelles générations de structures en diamant dopé au bore par technique de delta-dopage pour l'électronique de puissance : croissance par CVD et caractérisation." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00967208.
Повний текст джерелаАнотація:
Dans ce projet de thèse, qui s'appuie sur l'optimisation d'un réacteur de croissance du diamant et la construction d'un prototype, nous avons démontré l'épitaxie par étapes de couches de diamant, orientées (100), lourdement dopées au bore sur des couches de dopage plus faible dans le même processus, sans arrêter le plasma. Plus original, nous avons démontré la situation inverse. Nous présentons aussi des croissances assez lentes pour l'épitaxie de films d'épaisseur nanométriques avec de grands sauts de dopage, appelé delta-dopage. L'accent a été porté sur le gain en raideur des interfaces. Nous démontrons la présence d'interfaces fortement abruptes, issues de gravures in-situ optimisées, par une analyse conjointe en spectrométrie de masse à ionisation secondaire et en microscopie électronique en transmission à balayage en champ sombre annulaire aux grands angles. Des super-réseaux de dopages abrupts montrent des pics satellites de diffraction X typiques de la super-période.
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Ndoye, Coumba. "Characterization of Dopant Diffusion in Bulk and lower dimensional Silicon Structures." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/46321.
Повний текст джерелаАнотація:
The semiconductor industry scaling has mainly been driven by Mooreâ s law, which states that the number of transistors on a single chip should double every year and a half to two years. Beyond 2011, when the channel length of the Metal Oxide Field effect transistor (MOSFET) approaches 16 nm, the scaling of the planar MOSFET is predicted to reach its limit. Consequently, a departure from the current planar MOSFET on bulk silicon substrate is required to push the scaling limit further while maintaining electrostatic control of the gate over the channel. Alternative device structures that allow better control of the gate over the channel such as reducing short channel effects, and minimizing second order effects are currently being investigated.
Such novel device architectures such as Fully-Depleted (FD) planar Silicon On Insulator (SOI) MOSFETS, Triple gate SOI MOSFET and Gate-All-Around Nanowire (NW) MOSFET utilize Silicon on Insulator (SOI) substrates to benefit from the bulk isolation and reduce second order effects due to parasitic effects from the bulk. The doping of the source and drain regions and the redistribution of the dopants in the channel greatly impact the electrical characteristics of the fabricated device. Thus, in nano-scale and reduced dimension transistors, a tight control of doping levels and formation of pn junctions is required. Therefore, deeper understanding of the lateral component of the diffusion mechanisms and interface effects in these lower dimensional structures compared to the bulk is necessary.
This work focuses on studying the dopant diffusion mechanisms in Silicon nanomembranes (2D), nanoribbons (â 1.Xâ D), and nanowires (1D). This study also attempts to benchmark the 1D and 2D diffusion against the well-known bulk (3D) diffusion mechanisms.Master of Science
20
Kondratenko, Kirill. "Structural and charge transporting properties of pure liquid crystalline organic semiconductors and composites for applications in organic electronics." Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0536.
Повний текст джерелаАнотація:
Cette thèse est dédiée à divers aspects des semi-conducteurs organiques (SCO) cristaux liquides (CL) en ce qui concerne leurs applications dans le domaine de l'électronique organique. La première partie de ce travail concerne un SCO CL bien connu à base de phényle naphtalène. Deux moyens principaux d'amélioration de ses performances sont proposés et étudiés : la stabilisation in situ de la structure du CL par photo-polymérisation et l'introduction d'une impureté de dopage (accepteur d'électrons). Dans le premier cas, l'influence du réseau de polymères sur l'ordre et le transport de charge est étudiée à l'aide de techniques expérimentales classiques et par la mesure de la mobilité par la technique de "temps de vol". Pour les matériaux dopés, des calculs ab initio ont été utilisés pour prédire leurs propriétés spectroscopiques, qui sont comparées de manière exhaustive aux données expérimentales obtenues par spectroscopie optique et vibratoire. Les propriétés de transport de charge ont également été étudiés. Un prototype de transistor à effet de champ organique (OFET) a été réalisé afin d'obtenir une estimation des performances pour une application potentielle dans les dispositifs électriques à base de matériaux organiques.La deuxième partie de ce travail comprend la conception et la synthèse d'un nouveau semi-conducteur CL à base d'anthracène. Une attention particulière est portée pour obtenir un matériau relativement facile à synthétiser et à faible coût. La nouvelle molécule synthétisée est entièrement caractérisée : la structure moléculaire est confirmée par les techniques appropriées ; les niveaux d'énergie moléculaire frontières sont étudiés par spectroscopie optique et voltamétrie cyclique et comparés aux valeurs obtenues par calcul ab initio ; les propriétés de la mésophase sont étudiées par microscope optique et calorimétrie à balayage. La caractérisation des propriétés de transport de charge a été directement réalisé sur un dispositif OFET. La nouvelle molécule à base d'anthracène présente une amélioration significative de la mobilité des trous sous l'effet de champ par rapport au dérivé de phényle naphtalène étudié précédemment. Enfin, les propriétés photoconductrices du nouveau matériau sont abordées et montrent que cette molécule est très prometteuse dans le domaine des phototransistors organiquesThis thesis is dedicated to various aspects of liquid crystalline (LC) organic semiconductors (OSCs) in regard to their applications in the field of organic electronics. The first part of this work deals with a well-known LC OSC based on phenyl-naphtalene. Two major ways of performance improvement are proposed and investigated : stabilization of LC structure by in situ photo-polymerization and introduction of electron acceptor doping impurity. In the first case, the influence of polymer network on mesophase order and charge transport is investigated by conventional experimental techniques and Time-Of-Flight (TOF) mobility measurements. Fot the doped materials, ab initio calculations are employed to predict their spectroscopic properties which is exhaustively compared with the experimental data obtained by optical and vibrational spectroscopy. The charge transport is studied by TOF method in the mesophase, while crystalline phase is investigated via conductive atomic force microscopy. A prototype of organic field effect transistor (OFET) is prepared to obtain an estimate of performance for a relevant real-world application. The second part of this work includes design and synthesis of a novel LC semiconductor based on anthracene, additional attention is made to obtain an easy-to-make and low production cost material. Noval molecule is fully characterized : molecular structure is confirmed by relevant techniques ; frontier molecular energy levels are studied by optical spectroscopy and cyclic voltammetry and confronted to values obtaines via ab initio calculations ; mesophase properties are investigated by optical microscopy and scanning calorimetry. charge transporting properties are characterized by means of an OFET device : it is found that new anthracene-molecule exhibits significant improvement of field-effect hole mobility over previously studied phenyl naphtalene derivative. Finally, photoconductive properties of the novel material are addressed in order to investigate its potential applications to organic phototransistors
21
Tocci, Gabriele. "Performance estimation and Variability from Random Dopant Fluctuations in Multi-Gate Field Effect Transistors : a Simulation Study." Thesis, KTH, Integrerade komponenter och kretsar, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93419.
Повний текст джерелаАнотація:
As the formation of nearly abrupt p-n junctions in aggressively scaled transistors has become a complex task, a novel type of device in which there are no junctions has recently been suggested (J. P. Colinge et al., Nature 2010). The device of interest is referred to as the junctionless transistor, and it has demonstrated excellent functionality, with the advantage of a simpler fabrication process than conventional FETs. Despite the remarkable performances exhibited by the junctionless transistor, this device has to be tested against variability before it may be produced in large scale. Hence, the study of how the fluctuations in the number and in the position of the dopant atoms affects a large number of devices has been developed in this work. Such variability source is referred to as Random Dopant Fluctuations (RDF) and it is among the most critical ones for conventional MOSFETs. Our view is that RDF ought to largely affect the junctionless transistors. Hence, in this work we mainly aim at investigating the impact of RDF in these type of devices. Firstly, we provide a detailed analysis on the performance of an ideal junctionless transistor with a uniform non-random doping concentration, by mean of simulations developed using a TCAD software. Secondly, we investigate the effects of RDF in the junctionless transistor, as the principal aim of our study. Here, we determine how the I-V characteristics are affected by the random dopants and we illustrate fundamental the causes of the variations. A first estimation of the impact of RDF is provided by the illustration of the threshold voltage and beta [1] distributions, and by the computation of the fundamental statistical quantities relating to the two parameters. A further and last estimation is provided by the comparison obtained studying RDF on the inversion mode FET.
22
GILLMANN, GILBERT. "Dopage plan silicium dans l'arseniure de gallium." Paris 6, 1988. http://www.theses.fr/1988PA066256.
Повний текст джерелаАнотація:
Apres avoir rappele le principe de la technique de croissance d'epitaxie par jets moleculaires, presentation d'un ensemble de caracterisations magneto-electriques (effet hall a bas champ magnetique, magneto-resistance et effet a fort champ magnetique), mais aussi des resultats purement electriques de c(v). Analyses par spectroscopie de masse d'ions secondes et mesures de double diffraction x. Tres bon accord entre ces resultats experimentaux et les investigations theoriques sur ces structures. Application de la technique a l'elaboration de dopages intenses, de contact ohmiques non allies et de transistors a effet de champ dont le canal est constitue par un dopage plan. Les performances presentees montrent les potentialites des dopages plan dans l'application a des structures de plus en plus sophistiquees
23
Ravichandran, Karthik. "Nano-scale process and device simulation." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1125340288.
Повний текст джерела
24
Ludemann, Michael. "In situ Raman-Spektroskopie an Metallphthalocyaninen: Von ultradünnen Schichten zum organischen Feldeffekttransistor." Doctoral thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-206568.
Повний текст джерелаАнотація:
Im ersten Teil der Arbeit werden Signalverstärkungsmechanismen für Raman-Spektroskopie erschlossen und evaluiert. Die als geeignet bewerteten Methoden finden im zweiten Teil ihre Anwendung zur Untersuchung der vibronischen Eigenschaften von dünnen Manganphthalocyaninschichten, die anschließend mit Kalium interkaliert werden. Hierbei sind verschiedene Phasen identifizierbar, die ein ganzzahliges Verhältnis von Kaliumatomen zu Manganphthalocyaninmolekülen besitzen. Im dritten Teil werden die elektrischen Eigenschaften durch die Verwendung dieses Materialsystems als aktives Medium eines Feldeffekttransistors untersucht.
25
Lin, Tzer Min, and 林澤民. "Graded Multi-delta Doping Field Effect Transistor." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/62058468005186454091.
Повний текст джерела
26
Chen, Jenq-Shyan, та 陳政賢. "Investigation of InGaP/GaAs δ-doping Camel-Gate Field-Effect Transistors". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/19403957016661292797.
Повний текст джерелаАнотація:
碩士國立高雄師範大學
物理學系
91
In this article, a new δ-doping field-effect transistor utilizing an InGaP/GaAs camel-gate structure was fabricated and demonstrated. In this device, a low doped GaAs layer together with an n+-GaAs and an ultra-thin p+-InGaP layers form a high-barrier camel gate structure. The device employments of n+-GaAs/p+-InGaP/n-GaAs heterostructure gate and the δ-doping channel with heavy-doping level were used to improve transconductance linearity and enhance current drivability. For a 1 x 100 μm2 device, the experiment results show a drain saturation current of 112 mA, a maximum transconductance of 240 mS/mm, and a large VGS swing larger than 3.5 V with the transconductance higher than 200 mS/mm. The measured breakdown voltage is about 33 V. In addition, the measured unity current gain frequency ƒt is 22 GHz. Besides, an analytical model related to drain saturation current, transcondutance, potiential barrier height, gate-to-source depletion capacitance, and unity current gain frequency is developed to discuss the device performances. On the other hand, the simple analytical model related to drain I-V characteristic is also established. We also find that the experimental results are consistent with theoretical analysis.
27
Lin, K. W., and 林坤緯. "Investigation of InGaP/InGaAs/GaAs Step-Compositioned Doping-Channel Field-Effect Transistor." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/26060909650930207025.
Повний текст джерелаАнотація:
碩士國立成功大學
電機工程學系
85
In this thesis, we propose a novel structure of In0.49 Ga0.51 P/In GaAs/GaAs step-compositioned doped-channel field-effect transistor (SCDCFET). Due to the presence of V-shaped like energy band formed by the step-compositioned doped-channel structure, a large current density, a large gate voltage swing with high average transconductance and a high breakdown voltage are obtained. The physical properties of the SDCCFET are investigated in detailed experimentially and theoretically. In theoretically, we can clearly find the distribution of wave functions and electron density in the In GaAs V-shaped like channel. In addition, compared with triangle structure, the modulation of threshold voltage is obtained, too. Based on the theoretical analysis, the properties of each layer and the characteristics of interface may be obtained. This can improve the device performance.
28
Movva, Hema Chandra Prakash. "Self-aligned graphene field effect transistors with surface transfer doped source/drain access regions." Thesis, 2012. http://hdl.handle.net/2152/ETD-UT-2012-05-5788.
Повний текст джерелаАнотація:
Since its discovery in 2004, graphene has been widely touted as a potential replacement for silicon in the next generation of electronic circuits owing to its exceptionally high carrier mobilities and its ultra-thin body. Graphene field effect transistors (GFETs) show promising potential for use in analog and radio frequency (RF) applications, with theoretically predicted THz frequencies only being limited by fabrication challenges. High series resistance of the source/drain access regions in a GFET is one such major factor responsible for performance degradation. In this thesis, a simple and straightforward scheme of reducing this resistance by self-aligned spin-on-doping of graphene using surface transfer dopants is presented.
Back-gated GFETs were fabricated on Si/SiO2 and doped using various surface transfer dopants. A novel method of spin-on-doping graphene using poly(ethyleneimine) (PEI) was developed. Top-gated GFETs with mobilities up to 6,900 cm2/Vs were fabricated and their access regions were spin-on-doped in a self-aligned manner offering a 3X reduction in the series resistance. GFET drive currents improved by up to 4X and transconductances up to 3X after self-aligned doping. GFETs were also fabricated on insulating quartz substrates with mobilities up to 5,600 cm2/Vs and showed performance enhancements up to 2X after self-aligned doping.text
29
Cheng, Ching-Ping, and 鄭建平. "Simulation of gate overlap/underlap and source doping gradient of nanowire Tunnel Field-Effect Transistors." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/33a256.
Повний текст джерелаАнотація:
碩士國立東華大學
電機工程學系
107
In this paper ,we simulate Simulation of gate overlap/underlap and source doping gradient of nanowire Tunnel Field-Effect Transistors. First, we simulate different gate-source overlap/underlap structures in a fixed source concentration gradient and observe their I-V characteristics. Next, we simulated five different SDGs for each gate-source overlap/underlap structure and observed their device characteristics. The simulation results show that gate-source overlap structure has better device characteristics than gate-source underlap structure, but the device characteristics do not significantly improve with the increase of the overlap length. On the other hand, the SDG has Hardly affected on the device characteristics in the gate-source overlap structure, and the larger the SDG in the gate-source underlap structure, the better the device characteristics.
30
Chao, Yi-Ting, and 趙怡婷. "Investigation of channel profile on the performance of InGaP/InGaAs pseudomorphic doping-channel field-effect transistors." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/67388089979246328959.
Повний текст джерелаАнотація:
碩士國立高雄師範大學
電子工程學系
103
In this dissertation, two sets of InGaP/InGaAs pseudomorphic doping-channel field-effect transistors (DCFETs), doped by various In mole fraction in InGaAs channel, were analyzed and discussed. Through the different arrangement of channels, the device characteristics including the energy band diagrams, distribution of carrier, DC and microwave performance are investigated. Simultaneously, each of the studied devices show different device characteristics. We will study and make some inclusions at the end of this thesis. However, all the devices exhibit some good characteristics, such as high turn-on voltage, low leakage current, high current density, large swing, and high as well as linear transconductance. The studied devices show a great promise for high-speed, and high-frequency applications. First, three kinds of DCFETs, including GaAs/In0.1Ga0.9As/In0.2Ga0.8As (device A), In0.2Ga0.8As/In0.1Ga0.9As/GaAs (device B), and In0.1Ga0.9As (device C) doping channels, are studied as the total thickness of multiple channels is fixed at constant. Due to the high barrier and good carrier confinement, the device B shows a maximum drain saturation current of 52.9674 mA and a maximum transconductance value of 303.067 mS/mm. Compared with device A, though the conduction band discontinuity (ΔEc) at InGaP/In0.2Ga0.8As heterojunction in the device B is larger than that at InGaP/GaAs junction in the device A, the confinement effect for channel electrons in the device A is still good attributed to the sum of ΔEc values at three triple junctions. Moreover, in device A, a gate turn-on voltage of 0.9887V, a breakdown voltages of -10.51V, and a threshold voltages of -0.9V are obtained at equilibrium. However, the device C shows the best microwave characteristic among of the three devices. Second, the characteristics of InGaP/In0.1Ga0.9As (device C), InGaP/GaAs (device D), and InGaP/In0.2Ga0.8As (device E) DCFETs are discussed. Three kinds of DCFETs are studied as the thickness of channels is the same. Due to the highest barrier heights of the InGaP/In0.2Ga0.8As discontinuities and the best channel carrier confinement capability, the device E shows the best properties, including a maximum drain saturation current of 53.6875 mA, a maximum transconductance value of 294.576 mS/mm, and the good microwave properties in the three devices. Finally, we will make some conclusions to clarify the differences between these devices.
31
Chen, Chun-Hua, and 陳振華. "STUDIES ON THE DOPING CHARACTERISTICS AND METAL-OXIDE- SEMICONDUCTOR FIELD EFFECT TRANSISTOR FABRICATION OF POLYANILINE CONJUGATED POLYMER." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/37709462553567501844.
Повний текст джерелаАнотація:
碩士大同工學院
化學工程學系
85
In this study, studies on the characteristics of polyaniline doped withvarious acids (hydrochloric acid, sulfuric acid, phosphoric acid, p-toluenesulfonic acid monohydrate, bis(2- ethylhexyl)hydrogen phosphateand diphenyl phosphate are to be carried out. Polyaniline doped withbis(2-ethylhexyl)hydrogen phosphate and diphenyl phosphate can dissolve in common organic solvants. The FTIR characteristic bands of PANI dopedacid shift lower wavenumber than those of the PANI base form. The maximum UV-vis absorption spectra of PANI salts are located at higher wavenumber than those of the base form, which exhibit a red shift phenomena. The spin concentration of polyaniline salts can be calculated by EPR spectra. The resultsexhibit the correlation between the conductivity and spin concentration. In other worlds, the charge transport can be explained solely by the migration of paramagnetic polarons along the polymer chanis. The metal-oxide-semiconductor field-effect transistors (MOSFET) are frabricated with polyaniline doped with diphenyl phosphate as the semiconducting layer. These FETs belong to n-typetransistors and are found to be environmentally more stable than those ofother polyaniline FETs.
32
HUANG, Shao-Jia, and 黃紹嘉. "Study of Doping Layered-WSe2 Material as Field Effect Transistor Channel for Source/Drain Contact Resistance Reduction." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/04091130890836214975.
Повний текст джерелаАнотація:
碩士國立臺灣師範大學
光電科技研究所
104
Recently, two dimensional transition metal dichalcogenides (TMDs) compounds have drawn much interest due to their potential in TFT channel application than Graphene which without bandgap. Among these 2D materials, p-type WSe2 is particularly attractive. However, precise doping of WSe2 is difficult due to the absence of a controllable doping technique. In this paper, a controllable WSe2 doping method by co-sputtering process followed by post selenization treatment is demonstrated. Using this technique, high acceptor doping concentration and good hole mobility were obtained. Low sheet resistance and contact resistance were obtained.
33
HUANG, PO-HAO, and 黃柏豪. "Study of Metal Oxide Semiconductor Field Effect Humidity Sensing Device Using Titanium Dioxide Sensing Film with Nitrogen Doping." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/3f56bh.
Повний текст джерелаАнотація:
碩士國立高雄海洋科技大學
微電子工程研究所
102
The TiO2:N2 relative humidity sensing devices were accomplished in accordance with semiconductor structures. The optimum growth parameter of TiO2:N2 sensing film was decided to fabricate the well-defined relative humidity sensor. In this study, the optimum growth temperature of TiO2:N2 sensing film is at 27oC with well properties in the surface morphology, crystallization, and electronic transportation. By the Hall effect measurement, the TiO2:N2 sensing film is revealed the n-type in carrier type. The carrier concentration and mobility of TiO2:N2 sensing films are 3.4×1018 cm3 and 3.4 cm2/Vs respectively. The resistivity and conductivity of TiO2:N2 sensing films are also 1.8Ω-cm and 2.9/Ω-cm respectively. The TiO2:N2 relative humidity sensing devices were fabricated by using photo lithography and lift-off techniques. The adsorption time and desorption time of TiO2:N2 relative humidity sensing devices are respectively 30 seconds from 30% RH up to 90% RH and 65 seconds from 90% RH down to the 30% RH. The sensitivities of TiO2:N2 relative humidity sensing devices in hysteresis and I-V characteristics are respectively 0.12 and 10.41.
34
Shin, Nara. "Enhancement of n-channel Organic Field-Effect Transistor Performance through Surface Doping and Modification of the Gate Oxide by Aminosilanes." Doctoral thesis, 2019. https://tud.qucosa.de/id/qucosa%3A35131.
Повний текст джерелаАнотація:
In this these, in order to enhance the n-channel organic field-effect transistor (OFET) performance, amino functionalized self-assembled monolayers (A-SAMs) which consist of amino groups, a well-known n-type dopant candidate, were introduced from the top of OFET surfaces and on the gate oxide surfaces. To obtain better understanding for optimization of OFET performances we attempted to elucidate the mechanism of surface doping and surface modification by A-SAMs. Both the surface doping and surface modification of the gate oxide approaches have individual pros and cons. One needs to take into account the surface energy properties of SAMs and the resulting OSC film structure and pick the most suitable method to introduce the SAM material to the OFET (either doping or oxide modification) in order to obtain optimized device performances. Our study strongly suggests that both surface doping and surface modification of the gate oxide with A-SAMs could enhance other semiconductor-based electronic device performances.:Abstract v
Chapter 1. Introduction 1
Chapter 2. Theoretical Background 7
2.1. Organic Semiconductors (OSCs) 8
2.1.1. Semiconducting properties of organic molecules 8
2.1.2. Charge Transport Mechanism in OSCs 10
2.2. Organic Field-Effect Transistors (OFETs) 18
2.2.1. Operation Principle 18
2.2.2. Device Geometry of OFETs 20
2.2.3. Contacts (metal/semiconductor junction) in OFETs 21
2.2.4. Dielectric material for OFETs 23
2.2.5. Current-Voltage Characteristics of OFETs 25
2.3. Dominant contributors to OFET Performance 32
2.3.1. Molecular structure and Orientation of OSCs 32
2.3.2. Dielectric/OSC Interface 33
2.3.3. OSC/Contact Interface (Contact resistance) 35
2.3.4. Shallow and deep traps 36
2.4. Strategies to improve OFET performance 37
2.4.1. Introducing dopants to OFETs 37
2.4.2. Modification of Gate Oxide Layer with SAMs 44
Chapter 3. Experimental 51
3.1. Device Fabrication 52
3.1.1. Device type I - Substrate/ODTMS/PTCDI-C8/Au 53
3.1.2. Device type II - Substrate/ODTCS/N2200 (PNDI2OD-2T)/Au 53
3.1.3. Device type III - Substrate/SAMs/PTCDI-C8/Au 54
3.2. Surface doping process 56
3.2.1. Surface dopant – Aminosilanes (A-SAMs) 56
3.2.2. Surface doping method 56
3.3. Characterization 59
3.3.1. Material characterization 59
3.3.2. Surface-wetting characterization - Contact angle measurement 61
3.3.3. Micro-structure characterization - Atomic Force Microscopy (AFM) 62
3.3.4. Surface potential characterization – Kelvin Probe Force Microscopy (KPFM) 63
3.3.5. Molecular Structure Characterization - Grazing Incidence Wide Angle X-ray Scattering (GIWAXS) 64
3.3.6. Electrical Characterization - Current-voltage (I-V) measurement 66
Chapter 4. Result and Discussion 69
4.1. Optimization of OFETs based on PTCDI-C8 and N2200 70
4.1.1. PTCDI-C8 OFETs 70
4.1.2. N2200 OFETs 72
4.1.3. Device measurement condition 75
4.2. Investigation of Surface doping mechanism of Aminosilanes 77
4.2.1. Surface doping effect depending on the dopant processing method 77
4.2.2. Surface doping effect for different types of organic semiconductors 80
4.2.3. Surface doping effect for different types of surface dopants 89
4.2.4. Surface doping effect for different OSC grain sizes 92
4.2.5. Surface doping effect for different OSC film thicknesses 103
4.2.6. Molecular structure of the doped films identified by GIWAXS 106
4.2.7. Stability of the surface doped OFETs 107
4.2.8. Summary 111
4.3. Modification of the gate oxide with various self-assembled monolayers 112
4.3.1. The surface property of SAM-treated substrates 112
4.3.2. The relation between the OSC morphology and the field-effect mobility 115
4.3.3. The origin of the threshold voltage shift 126
4.3.4. Memristive effects in PTCDI-C8 devices on ODTMS 133
4.3.5. Summary 137
4.4. Comparison of the surface doping and the modification of the gate dielectric 138
4.4.1. The reliability factor of OFETs 138
4.4.2. The threshold voltages and field-effect mobility of OFETs 141
4.4.3. Density of Interfacial trap sites and SAM induced mobile carriers 143
4.4.4. Summary 144
Chapter 5. Conclusion 145
Bibliography 148
List of Figures 158
List of Tables 166
List of Equations 167
Acknowledgment 168
Erklärung zur Eröffnung des Promotionsverfahrens 169
35
Winkler, Felix. "Through Silicon Via Field-Effect Transistor with Hafnia-based Ferroelectrics and the Doping of Silicon by Gallium Implantation Utilizing a Focused Ion Beam System." 2020. https://tud.qucosa.de/id/qucosa%3A72882.
Повний текст джерелаАнотація:
3-dimensional integration has become a standard to further increase the transistor density and to enhance the integrated functionality in microchips. Integrated circuits are stacked on top of each other and copper-filled through-silicon VIAs (TSVs) are the industry-accepted choice for their vertical electrical connection. The aim of this work is to functionalize the TSVs by implementing vertical field-effect transistors inside the via holes. The front and back sides of 200 ... 300 µm thin silicon wafers were doped to create the source/drain regions of n- and p-FETs. The TSVFETs showed very stable saturation currents and on/off current ratios of about 10^6 (n-TSVFET) and 10^3 (p-TSVFET) for a gate voltage magnitude of 4V. The use of hafnium zirconium oxide on a thin SiO_2 interface layer as gate dielectric material in a p-TSVFET, enabled the implementation of a charge trapping memory inside the TSVs, showing a memory window of about 1V. This allows the non-volatile storage of the transistor on/off state. In addition, the demonstration of the use of gallium as the source/drain dopant in planar p-FET test structures (ion implanted from a focused ion beam tool) paves the way for maskless doping and for a process flow with a low thermal budget. It was shown, that ion implanted gallium can be activated and annealed at relatively low temperatures of 500 °C ... 700 °C.:Abstract / Kurzzusammenfassung
Danksagung
Index I
List of Figures III
List of Tables X
List of Symbols XI
List of Abbreviations XV
1 Introduction 1
2 Fundamentals 5
2.1 Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) 5
2.1.1 Historical Development - Technological Advancements 7
2.1.2 Field-Effect Transistors in Semiconductor Memories 10
2.2 3D Integration and the Use of TSVs (Through Silicon VIAs) 16
2.3 Doping of Silicon 19
2.3.1 Doping by Thermal Diffusion 20
2.3.2 Doping by Ion Implantation 22
3 Electrical Characterization 24
3.1 Resistivity Measurements 24
3.1.1 Resistance Determination by Four-Point Probes Measurement 24
3.1.2 Contact Resistivity 27
3.1.3 Doping Concentration 32
3.2 C-V Measurements 35
3.2.1 Fundamentals of MIS C-V Measurements 35
3.2.2 Interpretation of C-V Measurements 37
3.3 Transistor Measurements 41
3.3.1 Output Characteristics (I_D-V_D) 41
3.3.2 Transfer Characteristics (I_D-V_G) 42
4 TSV Transistor 45
4.1 Idea and Motivation 45
4.2 Design and Layout of the TSV Transistor 47
4.2.1 Design of the TSV Transistor Structures 47
4.2.2 Test Structures for Planar FETs 48
5 Variations in the Integration Scheme of the TSV Transistor 51
5.1 Doping by Diffusion from Thin Films 51
5.1.1 Determination of Doping Profiles 52
5.1.2 n- and p- TSVFETs Doped Manufactures by the Use of the Diffusion Technique 59
5.2 Ferroelectric Hafnium-Zirconium-Oxide (HZO) in the Gate Stack 81
5.2.1 Planar ferroelectric p-MOSFETs Doped by Thermal Diffusion 82
5.2.2 p-TSVFETs with Hafnium-Zirconium-Oxide Metal Gate 90
5.3 Doping by Ion Implantation of Gallium with a Focused Ion Beam (FIB) Tool 96
5.3.1 Ga doped Si Diodes 97
5.3.2 Planar p-MOSFETs Doped by Ga Implantation 108
5.3.3 Proposal for a parallel integration of Cu TSVs and p-TSVFETs 117
6 Summary and Outlook 120
Bibliography XVIII
A Appendix XXXVI
A.1 Resistivity and Dopant Density XXXVI
A.2 Mask set for the TSVFET XXXVII
A.3 Mask Design of the Planar Test Structures XXXVIII
Curriculum Vitae XXXIX
List of Scientific Publications XLI
36
Gaspar, Diana Filipa Pereira. "Active cellulose-based substrates for application in eletronic devices." Doctoral thesis, 2019. http://hdl.handle.net/10362/77144.
Повний текст джерела
37
Kleemann, Hans. "Organic Electronic Devices - Fundamentals, Applications, and Novel Concepts." Doctoral thesis, 2012. https://tud.qucosa.de/id/qucosa%3A25534.
Повний текст джерелаАнотація:
This work addresses two substantial problems of organic electronic devices: the controllability and adjustability of performance, and the integration using scalable, high resolution patterning techniques for planar thin-film transistors and novel vertical transistor devices. Both problems are of particular importance for the success of transparent and flexible organic electronics in the future.
To begin with, the static behavior in molecular doped organic pin-diodes is investigated. This allows to deduce important diode parameters such as the depletion capacitance, the number of active dopant states, and the breakdown field. Applying this knowledge, organic pin-diodes are designed for ultra-high-frequency applications and a cut-off-frequency of up to 1GHz can be achieved using optimized parameters for device geometry, layer thickness, and dopant concentration.
The second part of this work is devoted to organic thin-film transistors, high resolution patterning techniques, as well as novel vertical transistor concepts. In particular, fluorine based photo-lithography, a high resolution patterning technique compatible to organic semiconductors, is introduced fielding the integration of organic thin-film transistors under ambient conditions. However, as it will be shown, horizontal organic thin-film transistors are substantially limited in their performance by charge carrier injection. Hence, down-scaling is inappropriate to enlarge the transconductance of such transistors. To overcome this drawback, a novel vertical thin-film transistor concept with a vertical channel length of ∼50nm is realized using fluorine based photo-lithography. These vertical devices can surpass the performance of planar transistors and hence are prospective candidates for future integration in complex electronic circuits.
38
Lin, Chun-Yen, and 林俊言. "Effects of Dopant Activation on Poly-Silicon Tunnel Field-Effect Transistors." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/38253608707521858613.
Повний текст джерелаАнотація:
碩士國立交通大學
電子物理系所
103
Tunnel field-effect transistor (TFET) is considered as a promising candidate for future ultra-low power device. It has been known that TFET exhibits ultra-low leakage current, higher on/off current ratio and lower than 60 mV/dec subthreshold swing at room temperature. This study discusses the effect of activation on polycrystalline silicon (poly-Si) TFETs by utilizing different annealing conditions. Compared with TFET annealed by SPC at 600 ℃ for 24 hours, the n-channel TFET (NTFET) annealed by 1000 ℃ spike exhibits 2.2-fold higher on current but slight degradation of average subthreshold swing (S.S.ave). For p-channel TFET (PTFET), 900-℃ 30-sec PTFET has 1.8-fold higher on current but also sight degradation of S.S.ave. These experimental results demonstrate that the higher on current is due to higher amount of dopant activation and S.S. strongly depends on the extent of dopant diffusion. On the other hand, microwave annealing (MWA) is used to activate dopant. Unlike the high temperature activation, MWA is considered as low temperature annealing which can suppress dopant diffusion. Therefore, both type of TFETs annealed by MW shows higher on/off ratio and superior S.S.. The addition, the lower threshold voltage (Vth) of MW TFET indicates higher tunneling probability due to the smaller extent of dopant diffusion. From these result, we found that MWA has potential application in future TFET technology.
39
Fromm, Felix Jonathan. "Raman-Spektroskopie an epitaktischem Graphen auf Siliziumkarbid (0001)." Doctoral thesis, 2014. https://monarch.qucosa.de/id/qucosa%3A20232.
Повний текст джерелаАнотація:
Die vorliegende Arbeit behandelt die Charakterisierung von epitaktischem Graphen auf Siliziumkarbid (0001) mittels Raman-Spektroskopie. Nach der Einführung theoretischer sowie experimenteller Grundlagen werden das Wachstum von Graphen auf Siliziumkarbid (SiC) behandelt und die untersuchten Materialsysteme vorgestellt.
Es wird gezeigt, dass das Raman-Spektrum von epitaktischem Graphen auf SiC (0001) neben den Phononenmoden des Graphens und des Substrats weitere Signale beinhaltet, welche der intrinsischen Grenzflächenschicht, dem Buffer-Layer, zwischen Graphen und SiC zugeordnet werden können. Das Raman-Spektrum dieser Grenzflächenschicht kann als Abbild der phononischen Zustandsdichte interpretiert werden. Fortführend werden verspannungsinduzierte Änderungen der Phononenenergien der G- und 2D-Linie im Raman-Spektrum von Graphen untersucht. Dabei werden starke Variationen des Verspannungszustands beobachtet, welche mit der Topographie der SiC-Oberfläche korreliert werden können und erlauben, Rückschlüsse auf Wachstumsmechanismen zu ziehen. Die Entwicklung einer neuen Messmethode, bei der das Raman-Spektrum von Graphen durch das SiC-Substrat aufgenommen wird, ermöglicht die detektierte Raman-Intensität um über eine Größenordnung zu erhöhen. Damit wird die Raman-spektroskopische Charakterisierung eines Graphen-Feldeffekttransistors mit top gate ermöglicht und ein umfassendes Bild des Einflusses der Ladungsträgerkonzentration und der Verspannung auf die Positionen der G- und 2D-Raman-Linien von quasifreistehendem Graphen auf SiC erarbeitet.
40
Wang, Yu-Long, and 王裕隆. "Improving electrical characteristics of Fin-shaped Tunneling-Field-Effect-Transistor using Microwave dopant activation and Asymmetry structure." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/45990305348300769134.
Повний текст джерелаАнотація:
碩士國立清華大學
工程與系統科學系
101
The market demand for portable electric equipment increase dramatically year by year. Although transistors develop toward low cost and high density, maintaining device characteristics becomes difficult due to the device fabrication and physics limitations of the device. Designing a device that different from conventional MOSFET is a necessary way. This thesis based on Fin-shaped Tunneling Transistor which operated by quantum tunneling mechanism. Thus, compared with conventional MOSFET operated by drift mechanism, the Tunneling Transistor can achieve fast on/off characteristic. By the Fin-shaped structure, it can affect the active layer electric potential distribution by multi-direction, increasing the gate control ability and enhance the characteristics. Above the discussion, the Fin-shaped tunneling transistor is a device with high-efficiency and good transfer characteristic. In this thesis, we focus on demonstrate that microwave dopant activation technique can help TFETs to form an abrupt tunneling junction. Subthreshold slope and driving current can be greatly enhanced by microwave annealing as the dopant activation method compare to traditional rapid thermal annealing. An interesting phenomenon of negative differential conductance in the output characteristic was observed, which is attributed to hot-carrier effect at the high gate overdrive operation. A positive temperature dependence of transfer characteristic is also observed, which is related to the bandgap narrowing effect and the enhancement of the thermionic field emissions of the grain boundary states. Finally, with the geometric difference between source and drain, we demonstrate a device with high on-state current and low off-state current, simultaneously. This work shows experimental data for device’s reliability; all the data can display Fin-shaped tunneling transistor has applied to high value actually, it would become the next-generation device.
41
Ludemann, Michael. "In situ Raman-Spektroskopie an Metallphthalocyaninen: Von ultradünnen Schichten zum organischen Feldeffekttransistor." Doctoral thesis, 2014. https://monarch.qucosa.de/id/qucosa%3A20482.
Повний текст джерелаАнотація:
Im ersten Teil der Arbeit werden Signalverstärkungsmechanismen für Raman-Spektroskopie erschlossen und evaluiert. Die als geeignet bewerteten Methoden finden im zweiten Teil ihre Anwendung zur Untersuchung der vibronischen Eigenschaften von dünnen Manganphthalocyaninschichten, die anschließend mit Kalium interkaliert werden. Hierbei sind verschiedene Phasen identifizierbar, die ein ganzzahliges Verhältnis von Kaliumatomen zu Manganphthalocyaninmolekülen besitzen. Im dritten Teil werden die elektrischen Eigenschaften durch die Verwendung dieses Materialsystems als aktives Medium eines Feldeffekttransistors untersucht.:1. Einleitung
2. Theoretische Grundlagen der angewendeten Effekte
3. Experimentelle Details
4. Herstellung, Charakterisierung und Optimierung von Substraten für Raman-Oberflächenverstärkungseffekte
5. Untersuchung zu Verstärkungsmechanismen des Raman-Effekts an dünnen organischen Schichten
6. Interkalation mit Kalium in dünne Schichten aus Manganphthalocyanin
7. MnPc unter Spannungs- und Stromeinfluss - Der Feldeffekttransistor
8. Zusammenfassung
Anhang
Literatur
Abbildungsverzeichnis
Eidesstattliche Versicherung
Lebenslauf
Liste wissenschaftlicher Leistungen
Danksagung