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1

Brezeanu, Mihai. « Diamond Schottky barrier diodes ». Thesis, University of Cambridge, 2008. https://www.repository.cam.ac.uk/handle/1810/226757.

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Research on wide band gap semiconductors suitable for power electronicdevices has spread rapidly in the last decade. The remarkable results exhibited bysilicon carbide (SiC) Schottky batTier diodes (SBDs), commercially available since2001, showed the potential of wide band gap semiconductors for replacing silicon (Si)in the range of medium to high voltage applications, where high frequency operationis required. With superior physical and electrical properties, diamond became apotential competitor to SiC soon after Element Six reported in 2002 the successfulsynthesis of single crystal plasma deposited diamond with high catTier mobility. This thesis discusses the remarkable properties of diamond and introducesseveral device structures suitable for power electronics. The calculation of severalfigures of merit emphasize the advantages of diamond with respect to silicon andother wide band gap semiconductors and clearly identifies the areas where its impactwould be most significant. Information regarding the first synthesis of diamond,which took place back in 1954, together with data regarding the modern technologicalprocess which leads nowadays to high-quality diamond crystals suitable for electronicdevices, are reviewed. Models regarding the incomplete ionization of atomic dopantsand the variation of catTier mobility with doping level and temperature have beenelaborated and included in numerical simulators. The study introduces the novel diamond M-i-P Schottky diode, a version ofpower Schottky diode which takes advantage of the extremely high intrinsic holemobility. The structure overcomes the drawback induced by the high activationenergies of acceptor dopants in diamond which yield poor hole concentration at roomtemperature. The complex shape of the on-state characteristic exhibited by diamondM-i-P Schottky structures is thoroughly investigated by means of experimentalresults, numerical simulations and theoretical considerations. The fabrication of a ramp oxide termination on a diamond device is for thefirst time reported in this thesis. Both experimental and simulated results show thepotential of this termination structure, previously built on Si and SiC power devices. A comprehensive comparison between the ramp oxide and two other versions of thefield plate termination concept, the single step and the three-step structures, has beenperformed, considering aspects such as electrical performance, occupied area,complexity of technological process and cost. Based on experimental results presented in this study, together withpredictions made via simulations and theoretical models, it is concluded that diamondM-i-P Schottky diodes have the ability to deliver significantly higher performancecompared to that of SiC SBDs if issues such as material defects, Schottky contactformation and measurement of reliable ionization coefficients are carefully addressedin the near future.
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2

Yates, Kenneth Lee 1959. « Avalanche characteristics of silicide Schottky barrier diodes ». Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276634.

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This thesis investigates the use of an avalanche Platinum Silicide (PtSi) Schottky Barrier Diode as a detector in fiber optic communication systems for the 1.3 to 1.5 mum spectral region. The avalanche process is used to amplify the signal prior to electrical interfacing in order to enhance the signal-to-noise ratio. The amount of multiplication is predicted by the impact ionization coefficients for electrons and holes, alpha and beta, respectively. By using PtSi Schottky diodes, where alpha > beta, pure electron injection can be accomplished by irradiating with photons of energy psi hnu Eg (where psi is the Schottky Barrier height and Eg is the bandgap of silicon), thus maximizing multiplication and minimizing noise. An alternative means for avalanching involves the quantum effects of impurity-band ionization. By using a heavily doped semiconductor and operating at low temperatures, one can achieve noise-free gain at lower electric field strengths. (Abstract shortened with permission of author.)
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3

Blasciuc-Dimitriu, Cezar. « Theoretical modelling of Schottky barrier diodes in SiC ». Thesis, University of Newcastle Upon Tyne, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405314.

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4

Ngoepe, P. N. M. (Phuti Ngako Mahloka). « Optoelectronic characterisation of AlGaN based Schottky barrier diodes ». Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/24890.

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Recent advances in growth techniques have lead to the production of high quality GaN and this has played a vital role in the improvement of GaN based devices. A number of device types can be produced from GaN. Spectrally selective devices can be produced by creating ternary or quaternary material systems by partially substituting either Al or In for Ga in GaN. This allows a wide spectral range that can be achieved ranging from the visible to the ultraviolet. The applications of detectors based on these material systems are vast and include areas such as biological, military, environmental, industrial and scientific spheres. In front illuminated Schottky barrier photodetectors, two major factors influencing the sensitivity of the device are the reverse leakage current and the transparency of the Schottky contact. In order to reduce the reverse current of semiconductor based devices, increase the barrier height, and enhance the adhesion of a metal on a semiconductor it is important to subject the contact to annealing. Annealing studies have been performed on AlGaN based photodiodes to investigate the evolution of the optical and electrical properties. In this study, the electrical and optical characteristics of AlGaN based Ni/Au and Ni/Ir/Au Schottky photodiodes were investigated. The electrical properties of the photodiodes were optimised by annealing in an Ar ambient. An increase in the Schottky barrier height and a decrease in the reverse leakage current were observed with increasing annealing temperature up to 500 oC. This effect was observed for both the Ni/Au and Ni/Ir/Au photodiodes. The optical characteristics of the photodiodes, which include the responsivity and the quantum efficiency, were also investigated. UV/visible rejection ratios of as high as 103 were obtained. The transmittance of Ni/Au and Ni/Ir/Au metal layers deposited on a quartz substrate were optimised by annealing. This was under the same ambient conditions as the Schottky photodiode. The transmittance increased with annealing temperature for the Ni/Au metal layer whereas it decreased at higher temperatures for the Ni/Ir/Au layer. The transmittance of the Ni/Au metal layer reached as high as 85 % after 500 oC annealing. The transmittance of the Ni/Ir/Au only reached a high of 41 % after 400 oC annealing.
Dissertation (MSc)--University of Pretoria, 2013.
Physics
unrestricted
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5

Kummari, Rani S. « Improved SiC Schottky Barrier Diodes Using Refractory Metal Borides ». Connect to resource online, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1266422079.

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6

Xu, Hui Park Minseo. « Fabrication and electrical/optical characterization of bulk GaN-based Schottky diodes ». Auburn, Ala, 2009. http://hdl.handle.net/10415/1871.

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7

Korkmaz, Sibel. « Characterization Of Cds Thin Films And Schottky Barrier Diodes ». Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606623/index.pdf.

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CdS thin films were deposited by thermal evaporation method onto glass substrates without any doping. As a result of the structural and electrical investigation it was found that CdS thin films were of the polycrystalline structure and n-type
and of the transmission analysis optical band gap was found to be around 2.4 eV. Temperature dependent conductivity measurements were carried out in the range of 180 K &ndash
400 K. The dominant conduction mechanism is identified as tunnelling between 180 K &ndash
230 K and thermionic emission between 270 K and 400 K. To produce Schottky devices, CdS thin films were deposited onto the tin-oxide and indium-tin-oxide coated glasses, by the same method. Gold, platinum, carbon and gold paste were used as metal front contact in these devices. The area of these contacts were about...... Temperature dependent current-voltage measurements between 200 K and 350 K, room temperature current-voltage measurements, capacitance-voltage measurement in the frequency range 1 kHz &ndash
1 MHz and photoresponse measurements were carried out for the characterization of these diodes. Ideality factor of the produced Schottky devices were found to be at least 1.5, at room temperature. Dominant current transport mechanism in the diodes with gold contacts was determined to be tunnelling from the temperature dependent current voltage analysis. Donor concentration was calculated to be about ........ from the voltage dependent capacitance measurement.
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8

Magill, Stephen Hugh Samuel. « The application of Schottky barrier diodes to infrared imaging ». Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283889.

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9

Naredla, Sai Bhargav. « Electrical Properties of Molybdenum Silicon Carbide Schottky Barrier Diodes ». Youngstown State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ysu155901806279725.

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10

Kashefi-Naini, A. « A study of some transition metal-silicon Schottky barrier diodes ». Thesis, University of Kent, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375200.

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11

Burnett, George Evan. « STATISTICAL YIELD AND PRELIMINARY CHARACTERIZATION OF SiC SCHOTTKY BARRIER DIODES ». MSSTATE, 2001. http://sun.library.msstate.edu/ETD-db/theses/available/etd-04102001-093048/.

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High-voltage SiC Schottky barrier diodes have been fabricated with 1mm square contacts. The SBD?s were fabricated using both an argon implant and a field plate overlap for edge termination. The current-voltage characterization of the diodes is presented with statistical yield information on the first set of diodes produced from the Mississippi Center for Advanced Semiconductor Prototyping. After packaging, reverse bias breakdown voltages over 500V at 0.1 A/cm2 and an on-state forward voltage drop of less than 2.5V at 100 A/cm2 were demonstrated. A 0.65-0.85 eV barrier height was extracted from the SBD?s using I-V measurements. Field plate terminated devices demonstrated consistent, low standard deviation breakdown voltages and low leakage currents. The argon implanted devices demonstrated a higher breakdown voltage with higher leakage currents and a higher standard deviation. It was proven that the diodes followed the thermionic field emission model for up to one third of the breakdown voltage. Over 15,000 diodes have been tested and results analyzed in this work.
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12

Morrison, Dominique Johanne. « The fabrication and characterisation of 4H-SiC Schottky barrier diodes ». Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324784.

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13

MOONEY, JONATHAN MARTIN. « INVESTIGATION OF THE PROCESS OF INTERNAL PHOTOEMISSION IN PLATINUM SILICIDE SCHOTTKY BARRIER DIODES (DETECTOR, INFRARED) ». Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/188156.

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In this work, the theory of internal photoemission is reviewed and extended for the special case of platinum silicide Schottky barrier infrared photodiodes. Vickers' model of hot-electron-mode photodetection is recast in terms of hot-holes, and the effects of carrier energy loss due to phonon collisions, as well as the depletion of the occupation of the emitting states due to emission are included. The optical absorption of the Schottky diodes is measured and used to relate the quantum efficiency of the diodes to the internal yield as calculated from the model. By including the effects of the carrier energy loss due to phonon collisions and the depletion of the occupation of the emitting states in the model, one can resolve previously unexplained anomalies in the photoresponse data (the shape of the Fowler plots, the absolute magnitude of the yield, and the difference between the optical and thermal barriers). Independent estimates are obtained for the mean-free-path between hot-hole/phonon, hot-hole/cold-electron, and hot-hole/imperfection collisions as well as the mean phonon energy, mean transmission coefficient across the Schottky barrier, and the Fermi energy. The model is found to be in excellent agreement with the experimental data for parameter values consistent with those reported in the literature. Some degree of correlation is found to exist between the one free variable for each diode and the processing used for that diode. Namely, the temperature of the substrate during deposition is correlated with the value of the mean-free-path between imperfection scattering events.
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14

Zhou, Yi Park Minseo. « Bulk gallium nitride based electronic devices Schottky diodes, Schottky-type ultraviolet photodetectors and metal-oxide-semiconductor capacitors / ». Auburn, Ala., 2007. http://hdl.handle.net/10415/1401.

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15

Arnold, John Christopher 1964. « Modification of Schottky diode performance due to ion bombardment ». Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277047.

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An experimental and theoretical analysis of the effects of ion bombardment on Schottky diodes is presented. The experimentally observed shifts in diode performance are compared to the conditions of ion exposure. These experiments show that Schottky diodes exposed to ion beams show decreases in effective barrier heights and ideality factors, as well as increased incidence of premature reverse breakdown. The change in barrier height is found to be proportional to the energy of the individual ions and the total number of ions delivered to the surface. A numerical simulation of the damage process and device performance is developed. The model considers only the effect of ion exposure on the potential distribution within the metal-semiconductor junction. Comparison of experimental and modelled barrier shifts shows fair agreement, suggesting that enhancement of tunnelling currents is the dominant mechanism for barrier lowering.
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16

Kundeti, Krishna Chaitanya. « The Properties of SiC Barrier Diodes Fabricated with Ti Schottky Contacts ». Youngstown State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1495150103584503.

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17

Diale, Mmantsae Moche. « Schottky barrier diode fabrication on n-GaN for ultraviolet detection / ». Access to E-Thesis, 2009. http://upetd.up.ac.za/thesis/available/etd-02112010-211125/.

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18

Postoyalko, V. « The influence of interband states on the characteristics of Schottky barrier diodes ». Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.354437.

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19

Adedeji, Adetayo V. William John R. « Composite contact metallization on SiC for high temperature applications in air ». Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Summer/doctoral/ADEDEJI_ADETAYO_15.pdf.

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20

Lioliou, Grammatiki. « Wide bandgap semiconductor radiation detectors for extreme environments ». Thesis, University of Sussex, 2017. http://sro.sussex.ac.uk/id/eprint/71077/.

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Wide bandgap semiconductor photodiodes were investigated for their suitability as radiation detectors for high temperature applications (≥ 20 °C), through measurements, calculations of key parameters of the devices, and relating the results back to the material, geometry of the detectors, environment under which the detectors were investigated, and previously published work. Three families of photodiodes were examined. 4H-SiC vertical Schottky UV photodiodes with Ni2Si interdigitated contacts were characterised for their response under dark and UV illumination. Electrical characterisation up to 120 °C and room temperature responsivity measurements (210 nm to 380 nm) suggested that the devices could operate at low UV light intensities, even at high visible and IR backgrounds without the use of filters, and at high temperatures. 4H-SiC Schottky photodiode detector arrays with planar thin NiSi contacts were investigated for X-ray (≤ 35 keV) detection and photon counting spectroscopy at 33 °C. The electrical characterisation of the devices up to 140 °C and subsequent analysis suggested that the devices are likely to operate as high temperature X-ray spectrometers. Results characterising GaAs p+-i-n+ mesa photodiode detectors for their room temperature visible and near infrared responsivity (580 nm to 870 nm), as well as their high temperature (≤ 60 °C) X-ray detection performance (at 5.9 keV) are presented. GaAs p+-i-n+ mesa photodiodes were also shown to be suitable for β- particle (electron) spectroscopy and X-ray fluorescence spectroscopy (≤ 21 keV) at 33 °C. The X-ray and electron spectroscopic measurements were supported by a comprehensive treatment of the noise components in charge sensitive preamplifiers. Calculations showed the potential benefits of using a SiC, rather than Si, JFET as the input transistor of such a preamplifier operating at high temperatures. The spectroscopic measurements, using both the 4H-SiC and GaAs photodiodes, are presented along with noise analysis to detangle the different noise components present in the reported spectrometers, identify the dominant source of noise, and suggest potential improvements for future spectrometers using the reported devices.
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21

Pang, Zhengda. « Schottky contacts to indium phosphide and their applications ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ30109.pdf.

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22

Hon, Kam Yan. « Surface plasmon resonance-assisted coupling to whispering-gallery modes in micropillar resonators and silicon microdisk-based depletion-type modulators using integrated schottky diodes / ». View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?ECED%202007%20HON.

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23

Wang, Ke, et 王科. « Some experimental studies of n-type GaN and Au/GaN contacts ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B26663612.

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24

Tivarus, Cristian Alexandru. « Schottky barrier formation at metal-quantum well interfaces studied with ballistic electron emission microscopy ». Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1134419471.

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25

Zhou, Jianming. « Indium tin oxide (ITO) deposition, patterning, and Schottky contact fabrication / ». LInk to online version, 2006. https://ritdml.rit.edu/dspace/handle/1850/1717.

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26

Los, Andrei. « Influence of carrier freeze-out on SiC Schottky junction admittance ». Diss., Mississippi State : Mississippi State University, 2001. http://library.msstate.edu/etd/show.asp?etd=etd-03272001-120540.

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27

Tsolis, George. « Experimental study of micro air vehicle powered by RF signal at 10 GHz / ». Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Dec%5FTsolis.pdf.

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Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, December 2003.
Thesis advisor(s): David C. Jenn, Jeffrey B. Knorr, Kevin Jones. Includes bibliographical references (p. 111-114). Also available online.
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28

Lima, Lucas Petersen Barbosa 1986. « Desenvolvimento de processos de eletrodos de porta (TaN e TiN) para dispositivos MOS ». [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259293.

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Orientador: José Alexandre Diniz
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-18T16:42:08Z (GMT). No. of bitstreams: 1 Lima_LucasPetersenBarbosa_M.pdf: 10518299 bytes, checksum: abe557fa5f682bd296c9fb416948d523 (MD5) Previous issue date: 2011
Resumo: Filmes de nitreto de titânio (TiN) e nitreto de tântalo (TaN) foram depositados sobre substratos de Si (100) utilizando um sistema de sputtering reativo, com diferentes fluxos de N2 (10-80 sccm) e potência (500-1500W), em ambiente de N2/Ar. Foram analisadas as influências da mistura gasosa N2/Ar e potência nas propriedades estruturais e elétricas dos filmes de TiN e TaN, utilizando as técnicas de perfilometria, microscopia de força atômica, 4 pontas, espectroscopia Raman, difração de raios-x e espectroscopia de fotoelétron. As análises físicas e elétricas dos filmes de TiN e TaN demonstram que os filmes são policristalinos, com as orientações preferenciais (311)-( 111) e (200)-( 111), respectivamente. Os valores das taxas de deposições, resistividades elétricas e tamanho de grão para os filmes de TiN e TaN estão entre 4 e 78 nm/min, 150 e 7500 ??.cm e 0,001 e 0,027 ?m2, respectivamente. Foram fabricados capacitores MOS e diodos Schottky com eletrodos superiores de TiN e TaN com dielétricos de SiOxNy ou SiO2, e extraídas curvas CV e IV destes dispositivos, para extração de parâmetros como tensão de flatband (VFB), densidade de carga efetiva (Q0/q) e função trabalho do eletrodo superior (WF). As curvas CV dos capacitores MOS com dielétrico de SiOxNy e eletrodo superior de TiN apresentaram valores extraídos de Q0/q, VFB e WF de 1010 cm2, 0,29 V e 4,65 eV, respectivamente, que são compatíveis com a tecnologia CMOS. As curvas CV dos capacitores MOS com dielétrico de SiOxNy e eletrodo superior de TaN apresentaram valores extraídos de Q0/q, VFB e WF de 1010 cm2, 1,36 V e 3,81 eV, respectivamente, que não são compatíveis com a tecnologia CMOS. As curvas CV dos capacitores MOS com dielétrico de SiO2 e eletrodo superior de TiN apresentaram valores extraídos de Q0/q, VFB e WF de 1010 e 1012 cm2, de 0,12 V e 0,36 V, e, 4,15 eV e 4,43 eV, respectivamente, que são compatíveis com a tecnologia CMOS. As curvas CV dos capacitores MOS com dielétrico de SiO2 e eletrodo superior de TaN apresentaram valores extraídos de Q0/q, VFB e WF de 1010 e 1012 cm2, 0,29 V e 0,20 V, e, 4,41 eV e 4,44 eV, respectivamente, que são compatíveis com a tecnologia CMOS. Estes resultados indicam que os filmes de TiN e TaN são compatíveis para serem utilizados em dispositivos da tecnologia MOS
Abstract: Tantalum nitride (TaN) and titanium nitride (TiN) films have been obtained by DC sputtering, using different nitrogen flow (10 - 80 sccm) and power (500 - 1500 W), in a nitrogen (N2)/argon (Ar) ambient on Si (100) substrates. The N2/Ar ratio in gas mixture and power effects on structural and electrical properties of TaN and TiN films were investigated by scan profiler (film thickness and deposition rate), atomic force microscopy (rms roughness and grain size), fourprobe technique (electrical resistivity), Raman spectroscopy, x-ray diffraction (crystal orientation) and X-ray photoelectron spectroscopy (film composition). The physical and structural analyses of TiN and TaN films show that TiN and TaN films were polycrystalline, with (311)-( 111) and (200)-( 111) preferred orientation, respectively. The deposition rates, electrical resistivities and grain size values of TiN and TaN films were between 4 and 78 nm/min, 150 and 7500 ??.cm and 0,001-0,027 ?m2, respectively. MOS capacitors and Schottky diodes were fabricated with TiN and TaN as upper electrodes and dielectrics with SiOxNy or SiO2. CV and IV measurements were carried out on these devices and flatband voltage (VFB), effective charge density (Q0/q) and metal gate work function (WF) were extracted from these measurements. The extracted values of Q0/q, VFB e WF 1010 cm2, 0,29 V e 4,65 eV, and these values were extracted from CV curves of MOS capacitors with TiN as gate electrode and SiOxNy as gate dielectric. The extracted values of Q0/q, VFB e WF 1010 cm2, 1,36 V e 3,81 eV, and these values were extracted from CV curves of MOS capacitors with TiN as gate electrode and SiOxNy as gate dielectric. The extracted values of Q0/q, VFB and WF were about 1010 and 1012 cm2, 0,12 V and 0,36V, and 4,15 eV and 4,43 eV, and these values were extracted from CV curves of MOS capacitors with TiN as gate electrode and SiO2 as gate dielectric. The extracted values of Q0/q, VFB and WF were about 1010 and 1012 cm2, 0,29 V and 0,20V, and 4,41 eV and 4,44 eV, and these values were extracted from CV curves of MOS capacitors with TaN as gate electrode and SiO2 as gate dielectric. These extracted values for VFB and WF indicates that the TiN and TaN films are suitable for MOS technology
Mestrado
Eletrônica, Microeletrônica e Optoeletrônica
Mestre em Engenharia Elétrica
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29

Allen, Noah Patrick. « Electrical Characterization of Gallium Nitride Drift Layers and Schottky Diodes ». Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/102924.

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Interest in wide bandgap semiconductors such as silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga 2 O 3 ) and diamond has increased due to their ability to deliver high power, high switching frequency and low loss electronic devices for power conversion applications. To meet these requirements, semiconductor material defects, introduced during growth and fabrication, must be minimized. Otherwise, theoretical limits of operation cannot be achieved. In this dissertation, the non-ideal current- voltage (IV) behavior of GaN-based Schottky diodes is discussed first. Here, a new model is developed to explain better the temperature dependent performance typically associated with a multi-Gaussian distribution of barrier heights at the metal-semiconductor interface [Section 3.1]. Application of this model gives researches a means of understanding not only the effective barrier distribution at the MS interface but also its voltage dependence. With this information, the consequence that material growth and device fabrication methods have on the electrical characteristics can be better understood. To show its applicability, the new model is applied to Ru/GaN Schottky diodes annealed at increasing temperature under normal laboratory air, revealing that the origin of excess reverse leakage current is attributed to the low-side inhomogeneous barrier distribution tail [Section 3.2]. Secondly, challenges encountered during MOCVD growth of low-doped GaN drift layers for high-voltage operation are discussed with focus given to ongoing research characterizing deep-level defect incorporation by deep level transient spectroscopy (DLTS) and deep level optical spectroscopy (DLOS) [Section 3.3 and 3.4]. It is shown that simply increasing TMGa so that high growth rates (>4 µm/hr) can be achieved will cause the free carrier concentration and the electron mobilities in grown drift layers to decrease. Upon examination of the deep-level defect concentrations, it is found that this is likely caused by an increase in 4 deep level defects states located at E C - 2.30, 2.70, 2.90 and 3.20 eV. Finally, samples where the ammonia molar flow rate is increased while ensuring growth rate is kept at 2 µm/hr, the concentrations of the deep levels located at 0.62, 2.60, and 2.82 eV below the conduction band can be effectively lowered. This accomplishment marks an exciting new means by which the intrinsic impurity concentration in MOCVD-grown GaN films can be reduced so that >20 kV capable devices could be achieved.
Doctor of Philosophy
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Allen, Noah P. « Electrical Characterization of Gallium Nitride Drift Layers and Schottky Diodes ». Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/102924.

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Interest in wide bandgap semiconductors such as silicon carbide (SiC), gallium nitride (GaN), gallium oxide (Ga 2 O 3 ) and diamond has increased due to their ability to deliver high power, high switching frequency and low loss electronic devices for power conversion applications. To meet these requirements, semiconductor material defects, introduced during growth and fabrication, must be minimized. Otherwise, theoretical limits of operation cannot be achieved. In this dissertation, the non-ideal current- voltage (IV) behavior of GaN-based Schottky diodes is discussed first. Here, a new model is developed to explain better the temperature dependent performance typically associated with a multi-Gaussian distribution of barrier heights at the metal-semiconductor interface [Section 3.1]. Application of this model gives researches a means of understanding not only the effective barrier distribution at the MS interface but also its voltage dependence. With this information, the consequence that material growth and device fabrication methods have on the electrical characteristics can be better understood. To show its applicability, the new model is applied to Ru/GaN Schottky diodes annealed at increasing temperature under normal laboratory air, revealing that the origin of excess reverse leakage current is attributed to the low-side inhomogeneous barrier distribution tail [Section 3.2]. Secondly, challenges encountered during MOCVD growth of low-doped GaN drift layers for high-voltage operation are discussed with focus given to ongoing research characterizing deep-level defect incorporation by deep level transient spectroscopy (DLTS) and deep level optical spectroscopy (DLOS) [Section 3.3 and 3.4]. It is shown that simply increasing TMGa so that high growth rates (>4 µm/hr) can be achieved will cause the free carrier concentration and the electron mobilities in grown drift layers to decrease. Upon examination of the deep-level defect concentrations, it is found that this is likely caused by an increase in 4 deep level defects states located at E C - 2.30, 2.70, 2.90 and 3.20 eV. Finally, samples where the ammonia molar flow rate is increased while ensuring growth rate is kept at 2 µm/hr, the concentrations of the deep levels located at 0.62, 2.60, and 2.82 eV below the conduction band can be effectively lowered. This accomplishment marks an exciting new means by which the intrinsic impurity concentration in MOCVD-grown GaN films can be reduced so that >20 kV capable devices could be achieved.
Doctor of Philosophy
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31

Hajsaid, Marwan. « Photoresponse study of platinum silicide Schottky-barrier diodes and electrical characterization of porous silicon with some device applications / ». free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9717171.

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陳土培 et Tupei Chen. « Studies of metal - semiconductor contacts : current transport, photovoltage, schottky barries heights and fermi level pinning ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31233491.

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Chen, Tupei. « Studies of metal - semiconductor contacts : current transport, photovoltage, schottky barries heights and fermi level pinning / ». [Hong Kong : University of Hong Kong], 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13814254.

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Moro, Melgar Diego. « Conception et optimisation de la tête haute fréquence d'un récepteur hétérodyne à 1.2 THz pour l'instrument JUICE-SWI ». Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066618/document.

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La conception, fabrication et caractérisation d’un récepteur hétérodyne à 1.2 THz a été effectuée par le Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA) et constitue la base de ce rapport de thèse. Les études, analyse et résultats présentés dans ce manuscrit ont été effectués dans le cadre la mission JUpiter ICe moon Explorer (JUICE). JUICE est la première des grandes missions proposées à l’agenda du programme spatial Cosmic Vision 2015-2025 de l’Agence Spatial Européenne (ESA). La mission satellitaire JUICE est consacrée à l’étude du système Jovien. La charge utile du satellite est composée de 10 instruments à l’état-de-l’art et d'une expérience. Le développement du récepteur hétérodyne à 1.2 THz présenté dans cette thèse est dédié à SWI, acronyme anglais de “Submillimeter Wave Instrument", qui, grâce à une résolution spectrale de 107, étudiera à partir de 2030 la structure, la composition et la dynamique des températures de la stratosphère et de la troposphère de Jupiter ainsi que les exosphères et les surfaces des lunes glacées. La partie haute fréquence du récepteur est complètement basée sur la technologie de diodes Schottky planaires sur membrane d'arséniure de galium (GaAs), appelées “Planar Schottky Barrier Diodes” (PSBDs) dans le manuscrit. La réalisation du canal à 1.2 THz de SWI basé sur la technologie Schottky et entièrement développé par le consortium européen, dont fait parti le LERMA, a été le défi le plus significatif rencontré par ce dernier. L'extrême réduction de la taille des anodes des diodes Schottky nécessaire pour monter aux fréquences du THz a été atteinte en collaboration avec le Laboratoire de Photonique et de Nanostructures (LPN) en utilisant la lithographie électronique pour la fabrication de véritables “Monolithic Microwave Integrated Circuits” (MMIC).Une partie importante du ce rapport de thèse et consacrée à l’étude des phénomènes physiques additionnels qui apparaissent quand les dimensions des diodes sont fortement réduites. En particulier, les modifications du comportement résistif et capacitif des diodes Schottky dues à des phénomènes microscopiques bidimensionnels ont été étudiées au moyen d’un simulateur bidimensionnel Monte Carlo (2D-MC), en collaboration avec l’Université de Salamanca, en Espagne.Comme détaillé dans ce manuscrit, la caractérisation précise du comportement capacitif de la diode Schottky est un point critique pour déterminer la plage de fréquences de leur utilisation pour une application donnée. Toute modélisation imprécise de cette propriété de la diode peut entrainer un décalage significatif de la plage de fréquences d’opération d'un circuit THz.Cependant, la modélisation précise des diodes Schottky à ultra-hautes fréquences, n'est qu'une des étapes requises pour réussir à concevoir correctement un circuit THz. L’analyse précise et méticuleuse de l’interaction entre le comportement électromagnétique du chip MMIC et le comportement physique des diodes Schottky a été le but le plus important poursuit dans ce travail doctoral pour le développement du récepteur à 1.2 THz. Cette tâche a été abordée en utilisant les outils commerciaux “High Frequency Simulation/Structure Software” (Ansys-HFSS) et “Keysight Advance Design System” (Keysight-ADS). La combinaison des simulations électromagnétiques des structures tridimensionnelles du chip MMIC (Ansys-HFSS) et les simulations du comportement électrique non-linéaire de la diode Schottky (Keysight-ADS) est la manière actuelle d'aborder la conception de ce type de circuits THz. Le modèle électrique analytique de la diode requis par l’outil ADS a été défini par l'auteur conformément aux résultats précédemment obtenus avec le simulateur physique Monte Carlo. L’implémentation du modèle étendu de la diode Schottky dans cette méthode pour la conception et l'optimisation de chaque étage du récepteur à 1.2THz, est le sujet développé dans ce rapport de thèse
The design, fabrication and testing of a frequency heterodyne receiver at 1.2 THz has been developed by Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères (LERMA) and it is the foundation of this dissertation. The studies, analysis and results presented in this manuscript have been carried out within the framework of the JUpiter ICe moon Explorer (JUICE) mission. JUICE is one of the proposed missions in the agenda of the European Space Agency (ESA) Cosmic Vision 2015-2025 program. The objective of the JUICE satellite mission is to study the Jovian system, especially the Jupiter atmosphere properties and the surface characteristics of its icy moons. Scientific equipment consisting of ten state-of-the-art instruments and one experiment comprise the payload of this satellite. The development of a 1.2 THz channel is part of the Submillimeter Wave Instrument (SWI) devoted to recovering the spectroscopy data of the Jupiter atmosphere and icy-moons’ surface composition. The scientific principle for this receiver is all-solid-state semiconductor technology based in GaAs Planar Schottky Barrier Diodes (PSBDs). The achievement of a 1.2 THz channel based in PSBDs totally developed by European partners was the major challenge proposed for SWI, with LERMA committed to this assignment. The required ultra-scaling of the Schottky anode size of PSBDs in the attainment of the THz range has been achieved in collaboration with Laboratoire de Photonique et de Nanostructures (LPN) using e-beam photolithography in the fabrication of Monolithic Microwave Integrated Circuits (MMIC). An important part of this dissertation addresses the appearance of additional physical phenomena when ultrascaling solid-state PSBDs. Particularly, the modification of the electrical resistivity and capacitance of SBDs due to two-dimensional phenomena has been studied by means of a physical microscopic Two-Dimensional Monte Carlo (2D-MC) simulator, in collaboration with the University of Salamanca, Salamanca, Spain. As discussed within this manuscript, the accurate characterization of the diode capacitance is one of the critical points when opening a frequency window in the required frequency range of a THz application. A misunderstanding of this modified capacitance during the design of these devices can lead to a considerable offset in the frequency range of the experimental module. However, the accurate modeling of PSBDs in such high frequency applications is only a part of the expertise required for the successful completion of this challenge. The accurate and meticulous analysis of the interrelationship between the electromagnetic behavior of the MMIC chip and the physical behavior of the integrated PSBDs is the main challenge faced in this dissertation for the development of the 1.2 THz receiver. This task has been addressed using the commercial Ansys High Frequency Simulation/Structure Software (Ansys-HFSS) and the Keysight Advance Design System (Keysight-ADS). The combination of the three-dimensional electromagnetic characterization of the chip structure (obtained with HFSS) with the non-linear electrical circuit simulation (carried out by ADS) of diodes is the current methodology for the design of these modules. The analytical electrical model of PSBDs required by ADS software has been defined by this author in agreement with the results obtained with the 2D-MC simulator. The implementation of this approach in the design and optimization of the different stages of the accomplished 1.2 THz receiver is the main subject of this dissertation. The interaction between the physical model of the PSBDs and the electromagnetic modeling of the structure will be discussed within the different chapters of this dissertation. Finally, the mechanical engineering of these applications must be addressed in this discussion
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Thion, Fabien. « Conception de protections périphériques applicables aux diodes Schottky réalisées sur diamant monocristallin ». Phd thesis, INSA de Lyon, 2012. http://tel.archives-ouvertes.fr/tel-00735791.

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Cette thèse se place dans le cadre du projet Diamonix, qui vise à établir une filière diamant en France. La thèse porte sur des travaux de dimensionnement de protection périphérique, structure nécessaire au bon fonctionnement des composants d'électronique de puissance. Le développement de protections périphériques applicables aux diodes Schottky sur diamant monocristallin nécessite plusieurs étapes. Après un premier chapitre détaillant l'état de l'art de l'utilisation de diamant en électronique de puissance, nous nous attardons sur la conception de protection périphérique basée sur une plaque de champ à l'aide de divers diélectriques et ensuite à l'aide d'un matériau semi-résistif dans le chapitre 2. Ces simulations sont réalisées à l'aide du logiciel SENTAURUS TCAD. Le troisième chapitre essaie de répondre aux problèmes technologiques posés par le chapitre 2. Nous avons ainsi développé une nouvelle technique de gravure basée sur une succession d'étapes utilisant Ar/O2 puis CF4/O2. Puis, dans un deuxième temps, nous avons réalisé des capacités Métal/Diélectrique/Diamant afin de qualifier le comportement des diélectriques sur le matériau diamant. Leur comportement est problématique mais il s'agit à notre connaissance de la première étude poussée de capacités sur diamant. Le chapitre 4 revient sur la fabrication et la caractérisation de diodes Schottky protégées à l'aide de plaques de champ sur divers diélectriques, les résultats obtenus étant mitigés. Enfin, la conclusion revient sur les résultats importants de simulation, de gravure, de caractérisation des capacités et des diodes Schottky pour ensuite s'élargir et donner des perspectives de travail.
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36

Umana-Membreno, Gilberto A. « A study of gamma-radiation-induced effects in gallium nitride based devices ». University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0015.

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[Truncated abstract] Over the past decade, the group III-nitride semiconducting compounds (GaN, AlN, InN, and their alloys) have attracted tremendous research efforts due to their unique electronic and optical properties. Their low thermal carrier generation rates and large breakdown fields make them attractive for the development of robust electronic devices capable of reliable operation in extreme conditions, i.e. at high power/voltage levels, high temperatures and in radiation environments. For device applications in radiation environments, such as space electronics, GaN-based devices are expected to manifest superior radiation hardness and reliability without the need for cumber- some and expensive cooling systems and/or radiation shielding. The principle aim of this Thesis is to ascertain the level of susceptibility of current GaN-based elec- tron devices to radiation-induced degradation, by undertaking a detailed study of 60Co gamma-irradiation-induced defects and defect-related effects on the electrical characteristics of n-type GaN-based materials and devices . . . While the irradiation-induced effects on device threshold voltage could be regarded as relatively benign (taking into account that the irradiation levels employed in this study are equivalent to more than 60 years exposure at the average ionising dose rate levels present in space missions), the observed device instabilities and the degradation of gate current characteristics are deleterious effects which will have a significant impact on the performance of AlGaN/GaN HEMTs operating in radiation environments at low temperatures, a combination of conditions which are found in spaceborne electronic systems.
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37

Ding, Yi. « Quantum well state of cubic inclusions in hexagonal silicon carbide studied with ballistic electron emission microscopy ». Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1086207334.

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Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xv, 150 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Jonathan P. Pelz, Dept. of Physics. Includes bibliographical references (p. 144-150).
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38

Zhang, Teng. « Caractérisations des défauts profonds du SiC et pour l'optimisation des performances des composants haute tension ». Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEI108/document.

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En raison de l'attrait croissant pour les applications haute tension, haute tempé-rature et haute fréquence, le carbure de silicium (SiC) continue d'attirer l'attention du monde entier comme l'un des candidats les plus compétitifs pour remplacer le sili-cium dans le champ électrique de puissance. Entre-temps, il est important de carac-tériser les défauts des semi-conducteurs et d'évaluer leur influence sur les dispositifs de puissance puisqu'ils sont directement liés à la durée de vie du véhicule porteur. De plus, la fiabilité, qui est également affectée par les défauts, devient une question incontournable dans le domaine de l'électricité de puissance.Les défauts, y compris les défauts ponctuels et les défauts prolongés, peuvent introduire des niveaux d'énergie supplémentaires dans la bande passante du SiC en raison de divers métaux comme le Ti, le Fe ou le réseau imparfait lui-même. En tant que méthode de caractérisation des défauts largement utilisée, la spectroscopie à transitoires en profondeur (DLTS) est supérieure pour déterminer l'énergie d'activa-tion Ea , la section efficace de capture Sigma et la concentration des défauts Nt ainsi que le profil des défauts dans la région d'épuisement grâce à ses divers modes de test et son analyse numérique avancée. La détermination de la hauteur de la barrière Schottky (HBS) prête à confusion depuis longtemps. Outre les mesures expérimentales selon les caractéristiques I-V ou C-V, différents modèles ont été proposés, de la distribution gaussienne du HBS au modèle de fluctuation potentielle. Il s'est avéré que ces modèles sont reliés à l'aide d'une hauteur de barrière à bande plate Phi_BF . Le tracé de Richardson basé sur Phi_BF ainsi que le modèle de fluctuation potentielle deviennent un outil puissant pour la caractérisation HBS. Les HBSs avec différents contacts métalliques ont été caractéri-sés, et les diodes à barrières multiples sont vérifiées par différents modèles. Les défauts des électrons dans le SiC ont été étudiés avec des diodes Schottky et PiN, tandis que les défauts des trous ont été étudiés dans des conditions d'injec-tion forte sur des diodes PiN. 9 niveaux d'électrons et 4 niveaux de trous sont com-munément trouvés dans SiC-4H. Une relation linéaire entre le Ea extrait et le log(sigma) indique l'existence de la température intrinsèque de chaque défaut. Cependant, au-cune différence évidente n'a été constatée en ce qui concerne l'inhomogénéité de la barrière à l'oxyde d'éther ou le métal de contact. De plus, les pièges à électrons près de la surface et les charges positives fixes dans la couche d'oxyde ont été étudiés sur des MOSFET de puissance SiC par polarisation de porte à haute température (HTGB) et dose ionisante totale (TID) provoquées par irradiation. Un modèle HTGB-assist-TID a été établi afin d'ex-plain l'effet de synergie
Due to the increasing appeal to the high voltage, high temperature and high fre-quency applications, Silicon Carbide (SiC) is continuing attracting world’s attention as one of the most competitive candidate for replacing silicon in power electric field. Meanwhile, it is important to characterize the defects in semiconductors and to in-vestigate their influences on power devices since they are directly linked to the car-rier lifetime. Moreover, reliability that is also affected by defects becomes an una-voidable issue now in power electrics. Defects, including point defects and extended defects, can introduce additional energy levels in the bandgap of SiC due to various metallic impurities such as Ti, Fe or intrinsic defects (vacancies, interstitial…) of the cristalline lattice itself. As one of the widely used defect characterization method, Deep Level Transient Spectroscopy (DLTS) is superior in determining the activation energy Ea , capture cross section sigma and defect concentration Nt as well as the defect profile in the depletion region thanks to its diverse testing modes and advanced numerical analysis. Determination of Schottky Barrier Height (SBH) has been confusing for long time. Apart from experimental measurement according to I-V or C-V characteristics, various models from Gaussian distribution of SBH to potential fluctuation model have been put forward. Now it was found that these models are connected with the help of flat-band barrier height Phi_BF . The Richardson plot based on Phi_BF along with the potential fluctuation model becomes a powerful tool for SBH characterization. SBHs with different metal contacts were characterized, and the diodes with multi-barrier are verified by different models. Electron traps in SiC were studied in Schottky and PiN diodes, while hole traps were investigated under strong injection conditions in PiN diodes. 9 electron traps and 4 hole traps have been found in our samples of 4H-SiC. A linear relationship between the extracted Ea and log(sigma) indicates the existence of the intrinsic temper-ature of each defects. However, no obvious difference has been found related to ei-ther barrier inhomogeneity or contact metal. Furthermore, the electron traps near in-terface and fixed positive charges in the oxide layer were investigated on SiC power MOSFETs by High Temperature Gate Bias (HTGB) and Total Ionizing Dose (TID) caused by irradiation. An HTGB-assist-TID model was established in order to ex-plain the synergetic effect
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39

White, Brad Derek. « Cathodoluminescence spectroscopy studies of aluminum gallium nitride and silicon device structures as a function of irradiation and processing ». Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1141325302.

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40

Polischuk, Vladimir. « Etude et réalisation de structure à base de silicium poreux en vue de la détection de gaz ». Ecully, Ecole centrale de Lyon, 1999. http://www.theses.fr/1999ECDL0016.

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Ce travail de thèse visait à étudier les potentialités du silicium poreux comme support d'un élément sensible pour les capteurs de gaz. Afin de comprendre les mécanismes de formation du silicium poreux nous avons eu recours à l'électrochimie fondamentale de silicium. Ainsi, les mesures I-V de l'interface silicium/solution d'acide fluorhydrique ont mis en évidence deux mécanismes compétitifs : la formation électrochimique de l'oxyde de silicium et sa dissolution par HF. De même, la nature de l'oxyde de silicium est discutée dans le cadre des diagrammes d'équilibres tension-ph du système silicium-eau. Dans le but de développer de nouveaux capteurs de gaz, nous avons élaboré des couches de silicium poreux modifiées ultérieurement par un métal catalytique. Dans le cas des structures de type diode (Pd/Sp/Si), l'épaisseur de la couche de silicium poreux contrôle les processus de transport de courant. La quantité du palladium déposée influe beaucoup sur la sensibilité des structures sous gaz. Ainsi, ce sont les structures avec une couche ultramince de palladium qui présentent les meilleures réponses à l'hydrogène. En s'appuyant sur le modelé d'une hétérojonction métal/silicium poreux/si ayant une couche mince de silicium poreux, nous avons relie ce phénomène a la variation des porteurs libres de la zone de charge d'espace du silicium. La mesure de la différence de potentiel de contact nous a permis d'étudier l'effet de l'adsorption d'hydrogène sur la surface de palladium supporte sur du silicium poreux. Malgré nos attentes, les structures a base du silicium poreux ont montré une faible amélioration de la sensibilité par rapport aux structures traditionnelles Pd/SiO2/Si. Par contre, elles étaient plus performantes en ce qui concerne la cinétique, donc le temps de réponse deux fois plus rapide.
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41

Walker, Dennis Eugene. « The role of defects on Schottky and Ohmic contact characteristics for GaN and AlGaN/GaN high-electron mobility transistors ». Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1141766860.

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Kleider, Jean-Paul. « Etude des centres profonds du silicium amorphe hydrogène a-Si:H par des mesures d'admittances de diodes Schottky : caractérisation d'interfaces SI ::(X)-N ::(1-X):H/A-SI:H sur des structures MIS ». Paris 6, 1987. http://www.theses.fr/1987PA066015.

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DDétermination des caractéristiques du silicium amorphe hydrogène par mesure et analyse des admittances de diodes Schottky fournies sur ce matériau: densité d'états en-dessous et au niveau de fermi avec section de capture efficace des électrons et énergie d'activation du matériel.
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43

Cammack, Darren S. « The control of metal-nInGaAs and nInAlAs interfaces by cryogenic processing ». Thesis, Sheffield Hallam University, 1999. http://shura.shu.ac.uk/19420/.

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The physical and chemical properties of In- and Au- interfaces with In[0.53]Ga[0.47]As/InP(100) and In[0.52]Al[0.48]As(100) formed at room and low temperatures have been studied. Current-voltage measurements have indicated that In contacts to Ino[0.53]Ga[0.47]As(100) formed at 80K exhibit significantly higher Schottky barriers (&phis;b=0.45 eV) than In diodes formed at 294K (&phis;b=0.30 eV), whereas Au diodes formed on In[0.53]Ga[0.47]As(100) at either low temperature or room temperature exhibit Ohmic behaviour. The reactions occurring during interface formation at room and low temperatures have been investigated using soft X-ray photoemission spectroscopy (SXPS) and Transmission Electron Microscopy (TEM).The results presented show that In metallisation of In[0.53]Ga[0.47]As(100) at room temperature results in a predominantly three dimensional mode of growth, accompanied by the out-diffusion of As. Low temperature (125K) metallisation appears to reduce clustering and inhibit As out-diffusion. Examination of the resulting interfaces by TEM confirm the more uniform nature of the metal layers formed at low temperature. Metallisation temperature seems to have little effect on the formation of Au-In[0.53]Ga[0.47]As(100) interfaces, other than to reduce the extent of overlayer clustering, with As out-diffusion apparent for both low and room temperature Au deposition. Interfaces formed between In and In[0.52]Al[0.48]As(100) at both low and room temperature were relatively abrupt with no out-diffusion of substrate species into the metal overlayer. Low temperature metallisation again appeared to reduce overlayer clustering, with TEM studies showing a smaller grain size at low temperature. Au deposition onto In[0.52]Al[0.48]As(100) produced similar interfaces formed at room and low temperature. As diffuses into the Au overlayer to form an Au/As compound at both temperatures, resulting in an interface that is complex and reacted. The degree of overlayer clustering is also thought to be much less pronounced for Au deposition compared to In deposition. Barrier heights measured by SXPS during the study, show good agreement with reported current-voltage measurements for Au and In diodes formed on both In[0.53]Ga[0.47]As/InP(100) and In[0.52]Al[0.48]As(100). Possible mechanisms for the observed adaptation of the pinning position are discussed in the context of current models of Schottky barrier formation.
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Liao, Si-yu. « Caractérisation électrique et électro-optique de transistor à base de nanotube de carbone en vue de leur modélisation compacte ». Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14254/document.

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Afin de permettre de développer un modèle de mémoire non-volatile basée sur le transistor à nanotube de carbone à commande optique qui est utilisée dans des circuits électroniques neuromorphiques, il est nécessaire de comprendre les physiques électroniques et optoélectroniques des nanotubes de carbone, en particulier l’origine de l'effet mémoire que présente ces transistors. C’est dans ce contexte général que cette thèse s'intègre. Le travail est mené sur trois plans :• Caractériser électriquement et optoélectroniquement des structures de test des CNTFETs et des OG-CNTFETs.• Développer un modèle compact pour les contacts Schottky dans les transistors à nanotube de carbone de la façon auto-cohérente basé sur le diamètre et la nature du métal d’électrode en utilisant la méthode de la barrière effective avec les paramètres nécessaires calibrés.• Modéliser l'OG-CNTFET selon les régimes de fonctionnement, lecture, écriture, effacement ou programmation pour application à une mémoire non-volatile en intégrant le mécanisme de piégeage et dépiégeage à l’interface polymère/oxyde
This PhD thesis presents a computationally efficient physics-based compact model for optically-gated carbon nanotube field effect transistors (OG-CNTFETs), especially in the non-volatile memory application. This model includes memory operations such as “read”, “write”, “erase” or “program”, and “reset” which are modeled using trapping and detrapping mechanisms at the polymer/oxide interface. The relaxation of the memory state is taken into account. Furthermore, the self-consistent modeling of Schottky barriers at contacts between the carbon nanotube channel and metal electrodes is integrated in this model applying the effective Schottky barrier method. The Schottky contact model can be included in CNTFET based devices for a typical biasing range of carbon nanotube transistors. This compact model is validated by the good agreement between simulation results and experimental data (I-V characteristics). In the non-volatile memory application, this model can fully reproduce device behaviors in transient simulations. A prediction study of the key technological parameter, the CNT diameter variety is established to expect its impact on the transistor performance, and more importantly, on the memory operation. In the other hand, this thesis presents a preliminary electric characterization (I-V) of CNTFETs and OG-CNTFETs for the device modeling database. A preliminary optoelectronic characterization method is proposed
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Chern, Kevin Tsun-Jen. « GaInN/GaN Schottky Barrier Solar Cells ». Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/52899.

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GaInN has the potential to revolutionize the solar cell industry, enabling higher efficiency solar cells with its wide bandgap range spanning the entire solar spectrum. However, material quality issues stemming from the large lattice mismatch between its binary endpoints and questionable range of p-type doping has thus far prevented realization of high efficiency solar cells. Nonetheless, amorphous and multi-crystalline forms of GaInN have been theorized to exhibit a defect-free bandgap, enabling GaInN alloys at any indium composition to be realized. But the range of possible p-type doping has not yet been determined and no device quality material has been demonstrated thus far. Nonetheless, a Schottky barrier design (to bypass the p-type doping issue) on single-crystal GaInN can be used to provide some insight into the future of amorphous and micro-crystalline GaInN Schottky barrier solar cells. Through demonstration of a functional single crystalline GaInN Schottky barrier solar cell and comparison of the results to the best published reports for more conventional p-i-n GaInN solar cells, this work aims to establish the feasibility of amorphous and multi-crystalline GaInN solar cells.
Ph. D.
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46

Nguyen, Duy Minh. « Conception et caractérisation de diodes en SiC pour la détermination des coefficients d'ionisation ». Phd thesis, INSA de Lyon, 2011. http://tel.archives-ouvertes.fr/tel-00679281.

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Le carbure de silicium (SiC) possède plusieurs propriétés exceptionnelles comme une large bande interdite, un champ électrique critique et une vitesse de saturation des porteurs élevée pour remplacer le silicium (Si) dans des domaines de fonctionnement jusque-là inaccessibles avec le Si. Un nombre important de démonstrateurs des composants de puissance en SiC faisant état de performances remarquables ainsi que la disponibilité commerciale des composants en SiC confirment la maturité de la filière SiC et montrent les progrès technologiques réalisés au cours des dernières années. Cependant, il existe peu d'études sur les coefficients d'ionisation du SiC, lesquels sont pourtant indispensables pour prévoir précisément la tenue en tension des composants de puissance en SiC. Ce travail contribue donc à mieux déterminer ces coefficients. Pour cela, un bon nombre de diodes spécialement conçues pour la détermination des coefficients d'ionisation du SiC par la technique OBIC (Optical Beam Induced Current) ont été réalisées sur différents wafers de SiC-4H et de SiC-6H, deux polytypes courant du SiC. Cette technique repose sur un faisceau de laser ultraviolet qui génère des paires électrons-trous dans la zone de charge d'espace d'une diode sous test. La mesure du courant résultant permet d'accéder aux coefficients d'ionisation. A partir des mesures OBIC sur les diodes réalisées, nous avons pu déduire les coefficients pour ces deux polytypes du SiC. Plus particulièrement, les coefficients d'ionisation du SiC-4H sont déterminés dans une large gamme de champ électrique grâce aux mesures sur les différents dopages. Les paramètres des coefficients déterminés dans ce travail peuvent être utilisés en conception de dispositifs haute tension pour prédire plus précisément l'efficacité de leur protection périphérique.
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47

Najari, Montassar. « Modélisation compacte des transistors à nanotube de carbone à contacts Schottky et application aux circuits numériques ». Phd thesis, Université Sciences et Technologies - Bordeaux I, 2010. http://tel.archives-ouvertes.fr/tel-00560346.

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Afin de permettre le développement de modèles manipulables par les concepteurs, il est nécessaire de pouvoir comprendre le fonctionnement des nanotubes, en particulier le transport des électrons et leurs propriétés électroniques. C'est dans ce contexte général que cette thèse s'intègre. Le travail a été mené sur quatre plans : • Développement de modèles permettant la description des phénomènes physiques importants au niveau des dispositifs, • Expertise sur le fonctionnement des nano-composants permettant de dégager les ordres de grandeurs pertinents pour les dispositifs, les contraintes, la pertinence de quelques procédés de fabrication (reproductibilité, taux de défauts), • Collection de caractéristiques mesurées et développement éventuel d'expériences spécifiques, • Expertise et conception des circuits innovatifs pour l'électronique numérique avec ces nano-composants. Mots clés — Modélisation compacte, transistor Schottky à nanotube de carbone, simulation circuit, cellule mémoire SRAM, effet tunnel, WKB.
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48

Karisan, Yasir. « Full-wave Electromagnetic Modeling of Electronic Device Parasitics for Terahertz Applications ». The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1419019102.

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49

Diale, M. (Mmantsae Moche). « Schottky barrier diode fabrication on n-GaN for altraviolet detection ». Thesis, University of Pretoria, 2010. http://hdl.handle.net/2263/28143.

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There are many potential areas for the utilization of GaN-based nitride materials, including ultraviolet photodetectors. Ultraviolet photodetectors are used in the military for missile plume detection and space communications. Medically, ultraviolet photodiodes are used in monitoring skin cancer. Schottky barrier metal-semiconductor contacts are choice devices for the manufacture of ultraviolet photodiodes due to higher short wavelength sensitivity and fast response. They also require simple fabrication technology; suffer lower breakdown voltages, and record larger leakage currents at lower voltages as compared to p-n structures of the same semiconductor material. Thus the formation of a Schottky contact with high barrier height, low leakage current, and good thermal stability in order to withstand high temperature processing and operation are some of the most important factors in improving the performance of Schottky barrier photodiodes to be used for ultraviolet detection. The first stage of this study was to establish a chemical cleaning and etching technique. It was found that KOH was suitable in reducing C from the surface and that (NH4)2S further reduced the surface oxides. The next phase of the work was to select a metal that will allow UV light to pass through at a high transmission percentage: a combination of annealed Ni/Au was found to be ideal. The transmission percentage of this alloy was found to be above 80%. The next phase was the fabrication of Ni/Au Schottky barrier diodes on GaN to study the electrical characteristics of the diodes. Electrical characterization of the diodes showed that the dominant current transport mechanism was thermionic emission, masked by the effects of series resistance, which resulted from the condition of the GaN surface. Finally, we fabricated GaN UV photodiodes and characterized them in the optoelectronic station designed and produced during this research. Device responsivity as high as 31.8 mA/W for GaN and 3.8 mA/W for AlGaN were recorded. The calculated quantum efficiencies of the photodiodes were 11 % for GaN and 1.7 % for AlGaN respectively.
Thesis (PhD)--University of Pretoria, 2010.
Physics
unrestricted
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50

Daubriac, Richard. « Caractérisation de techniques d'implantations ioniques alternatives pour l'optimisation du module source-drain de la technologie FDSOI 28nm ». Thesis, Toulouse, INSA, 2018. http://www.theses.fr/2018ISAT0031/document.

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Durant ces dernières années, l’apparition de nouvelles architectures (FDSOI, FinFETs ou NW-FETs) et l’utilisation de nouveaux matériaux (notamment SiGe) ont permis de repousser les limites des performances des dispositifs MOS et de contourner l’effet canal court inhérent à la miniaturisation des composants. Cependant, pour toutes ces nouvelles architectures, la résistance de contact se dégrade au fil des nœuds technologiques. Celle-ci dépend fortement de deux paramètres physiques : la concentration de dopants actifs proches de la surface du semi-conducteur et de la hauteur de barrière Schottky du contact siliciuré. De multiples procédés avancés ont été proposé pour améliorer ces deux paramètres physiques (pré-amorphisation, recuit laser, ségrégation de dopants, etc…). Afin d’optimiser les conditions expérimentales de ces nouvelles techniques de fabrication, il est primordial de pouvoir caractériser avec fiabilité leur impact sur les deux grandeurs physiques citées. Dans le cadre de cette thèse, deux thématiques dédiées à l’étude de chacun des paramètres sont abordées, explicitant les méthodes de caractérisation développées ainsi que des exemples concrets d’applications. La première partie concerne l’étude de la concentration de dopants actifs proches de la surface du semi-conducteur. Dans cet axe, nous avons mis en place une méthode d’Effet Hall Différentiel (DHE). Cette technique combine gravures successives et mesures par effet Hall conventionnel afin d’obtenir le profil de concentration de dopants actifs en fonction de la profondeur. Nous avons développé et validé une méthode de gravure chimique et de mesure électrique pour des couches ultra-minces de SiGe et de Si dopées. Les profils de concentration générés ont une résolution en profondeur inférieure à 1 nm et ont permis d’étudier de façon approfondie dans les premiers nanomètres proches de la surface de couches fabriquées grâce à des techniques d’implantation et de recuit avancées comme par exemple, la croissance en phase solide activée par recuit laser. La deuxième partie porte sur la mesure de hauteurs de barrière Schottky pour des contacts siliciurés. Durant cette étude, nous avons transféré une technique se basant sur des diodes en tête bêche pour caractériser l’impact de la ségrégation de différentes espèces à l’interface siliciure/semi-conducteur sur la hauteur de barrière Schottky d’un contact en siliciure de platine. Cette méthode de mesure associée à des simulations physiques a permis d’une part, d’extrairer avec fiabilité des hauteurs de barrières avec une précision de 10meV et d’autre part, d’effectuer une sélection des meilleures conditions de ségrégation de dopants pour la réduction de la hauteur de barrière Schottky. Pour conclure, ce projet a rendu possible le développement de méthodes de caractérisation pour l’étude de matériaux utilisés en nanoélectronique. De plus, nous avons pu apporter des éclaircissements concernant l’impact de techniques d’implantation ionique alternatives sur des couches de Si et SiGe ultrafines, et ce, dans le but de réduire la résistance de contact entre siliciure et semi-conducteur dans le module source-drain de transistors ultimes
During the past few decades, the emergence of new architectures (FDSOI, FinFETs or NW-FETs) and the use of new materials (like silicon/germanium alloys) allowed to go further in MOS devices scaling by solving short channel effect issues. However, new architectures suffer from contact resistance degradation with size reduction. This resistance strongly depends on two parameters: the active dopant concentration close to the semi-conductor surface and the Schottky barrier height of the silicide contact. Many solutions have been proposed to improve both of these physical parameters: pre-amorphisation, laser annealing, dopant segregation and others. In order to optimize the experimental conditions of these fabrication techniques, it is mandatory to measure precisely and reliably their impact on cited parameters.Within the scope of this thesis, two parts are dedicated to each lever of the contact resistance, each time precising the developed characterization method and concrete application studies. The first part concerns the study of the active dopant concentration close to the semi-conductor surface. In this axis, we developed a Differential Hall Effet method (DHE) which can provide accurate depth profiles of active dopant concentration combining successive etching processes and conventional Hall Effect measurements. To do so, we validated layer chemical etching and precise electrical characterization method for doped Si and SiGe. Obtained generated profiles have a sub-1nm resolution and allowed to scan the first few nanometers of layers fabricated by advanced ion implantation and annealing techniques, like solid-phase epitaxy regrowth activated by laser annealing. In the second part, we focused on the measurement of Schottky barrier height of platinum silicide contact. We transferred a characterization method based on back-to-back diodes structure to measure platinum silicide contacts with different dopant segregation conditions. The electrical measurements were then fitted with physical models to extract Schottky barrier height with a precision of about 10meV. This combination between measurements and simulations allowed to point out the best ion implantation and annealing conditions for Schottky barrier height reduction.To conclude, thanks to this project, we developed highly sensitive characterization methods for nanoelectronics application. Moreover, we brought several clarifications on the impact of alternative ion implantation and annealing processes on Si and SiGe ultra-thin layers in the perspective of contact resistance reduction in FDSOI source-drain module
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