F. Demangeot, J. Frandon, M. Renucci, B. Beaumont, P. Gibart
GaN layers grown on sapphire (0001) substrates were studied at room temperature by Raman Spectroscopy. Directional dependance of frequency and polarization properties of the extraordinary modes, resulting from the anisotropic wurtzite, was evidenced by macro- and micro-Raman measurements. Second order Raman spectra were recorded and their completely symmetric component was analyzed in terms of phonon density of states. Due to the lack of phonon spectrum calculations, use was made of available q-dispersion curves of the closely related ZnO compound for phonon assignment.
{"title":"Phonon dispersion in gallium nitride","authors":"F. Demangeot, J. Frandon, M. Renucci, B. Beaumont, P. Gibart","doi":"10.1109/SIM.1996.570889","DOIUrl":"https://doi.org/10.1109/SIM.1996.570889","url":null,"abstract":"GaN layers grown on sapphire (0001) substrates were studied at room temperature by Raman Spectroscopy. Directional dependance of frequency and polarization properties of the extraordinary modes, resulting from the anisotropic wurtzite, was evidenced by macro- and micro-Raman measurements. Second order Raman spectra were recorded and their completely symmetric component was analyzed in terms of phonon density of states. Due to the lack of phonon spectrum calculations, use was made of available q-dispersion curves of the closely related ZnO compound for phonon assignment.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134002014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Fang, D. Look, S. Kuisma, K. Saarinen, P. Hautojarvi
Point defects and the main electron traps in undoped semi-insulating GaAs grown by vertical gradient freeze and high- and low-pressure liquid encapsulated Czochralski techniques have been studied by positron annihilation (PAS) and thermally stimulated current (TSC) spectroscopies, respectively. We find good correlations between the concentrations of the TSC traps T/sub 2/ (0.63 eV) and T/sub 5/ (0.35 eV), and the PAS identified-defects As/sub Ga/ and V/sub As/, respectively. A good correlation between the concentration of intrinsic acceptors (V/sub Ga/ and Ga/sub As/) measured by PAS, and the total acceptor concentration measured by infrared absorption, is also found.
{"title":"Point defects in undoped semi-insulating GaAs: correlation between thermally stimulated current and positron annihilation spectroscopies","authors":"Z. Fang, D. Look, S. Kuisma, K. Saarinen, P. Hautojarvi","doi":"10.1109/SIM.1996.570928","DOIUrl":"https://doi.org/10.1109/SIM.1996.570928","url":null,"abstract":"Point defects and the main electron traps in undoped semi-insulating GaAs grown by vertical gradient freeze and high- and low-pressure liquid encapsulated Czochralski techniques have been studied by positron annihilation (PAS) and thermally stimulated current (TSC) spectroscopies, respectively. We find good correlations between the concentrations of the TSC traps T/sub 2/ (0.63 eV) and T/sub 5/ (0.35 eV), and the PAS identified-defects As/sub Ga/ and V/sub As/, respectively. A good correlation between the concentration of intrinsic acceptors (V/sub Ga/ and Ga/sub As/) measured by PAS, and the total acceptor concentration measured by infrared absorption, is also found.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"184 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134360309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noise characteristics are evaluated for SiGe/Si based n-channel HEMTs and p-channel MOSFETs. The analysis is based on a self-consistent solution of Schroedinger and Poisson's equations. The model predicts a superior minimum noise figure for an n-channel HEMT at 77 K. p-channel MOSFETs behave similar to n-channel devices operating at 300 K. The minimum noise figure decreases with increasing quantum well (QW) width for both n- and p-channel devices. However, the p-channel devices are less sensitive to QW width variation. Minimum noise temperature behaves similarly. As observed, a range of doped epilayer thickness exists where the minimum noise figure is a minimum for both n- and p-channel FETs.
{"title":"Noise performance of Si/Si/sub 1-x/Ge/sub x/ n-channel HEMTs and p-channel FETs","authors":"Kuo-Wei Liu, A. Anwar","doi":"10.1109/SIM.1996.571084","DOIUrl":"https://doi.org/10.1109/SIM.1996.571084","url":null,"abstract":"Noise characteristics are evaluated for SiGe/Si based n-channel HEMTs and p-channel MOSFETs. The analysis is based on a self-consistent solution of Schroedinger and Poisson's equations. The model predicts a superior minimum noise figure for an n-channel HEMT at 77 K. p-channel MOSFETs behave similar to n-channel devices operating at 300 K. The minimum noise figure decreases with increasing quantum well (QW) width for both n- and p-channel devices. However, the p-channel devices are less sensitive to QW width variation. Minimum noise temperature behaves similarly. As observed, a range of doped epilayer thickness exists where the minimum noise figure is a minimum for both n- and p-channel FETs.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132235941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Marcon, S. Koumetz, K. Ketata, M. Ketata, P. Launay
Be diffusion during post-growth annealing has been studied in InGaAs epitaxial layers. To explain the observed concentration profiles, two models have been proposed. A good agreement has been obtained between experimental and calculated data. The point defect concentration in epitaxial layers during diffusion in InGaAs is also discussed.
{"title":"Be diffusion in InGaAs epitaxial layers during rapid thermal annealing: an effective diffusivity approach and a nonequilibrium model","authors":"J. Marcon, S. Koumetz, K. Ketata, M. Ketata, P. Launay","doi":"10.1109/SIM.1996.570937","DOIUrl":"https://doi.org/10.1109/SIM.1996.570937","url":null,"abstract":"Be diffusion during post-growth annealing has been studied in InGaAs epitaxial layers. To explain the observed concentration profiles, two models have been proposed. A good agreement has been obtained between experimental and calculated data. The point defect concentration in epitaxial layers during diffusion in InGaAs is also discussed.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133969891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Valakh, B. N. Romaniuk, V. Artamonov, N. Klyui, A. Pérez‐Rodríguez, L. Calvo‐Barrio, C. Serre, J. Morante, B. Dietrich
The effect of thermal annealing and C/sup +/ implantation on the Raman spectra of Si/sub 1-x/Ge/sub x/ (x=0.22, 0.29) strained layers grown on Si is investigated. For the annealed samples, relaxation is only observed after annealing at temperatures higher than 800/spl deg/C. However, full relaxation is not achieved even after annealing at 1050/spl deg/C. Samples annealed at this temperature show a residual stress in the range of 8 Kbars. For the implanted samples (with C peak concentration close to 2%), there is not a substantial shift of the Si-Si mode, in spite of the significant stress compensation in the layers. The strong lattice microdistortion near the C atoms is likely the main reason of this effect.
{"title":"Raman scattering analysis of SiGe annealed and implanted layers","authors":"M. Valakh, B. N. Romaniuk, V. Artamonov, N. Klyui, A. Pérez‐Rodríguez, L. Calvo‐Barrio, C. Serre, J. Morante, B. Dietrich","doi":"10.1109/SIM.1996.571086","DOIUrl":"https://doi.org/10.1109/SIM.1996.571086","url":null,"abstract":"The effect of thermal annealing and C/sup +/ implantation on the Raman spectra of Si/sub 1-x/Ge/sub x/ (x=0.22, 0.29) strained layers grown on Si is investigated. For the annealed samples, relaxation is only observed after annealing at temperatures higher than 800/spl deg/C. However, full relaxation is not achieved even after annealing at 1050/spl deg/C. Samples annealed at this temperature show a residual stress in the range of 8 Kbars. For the implanted samples (with C peak concentration close to 2%), there is not a substantial shift of the Si-Si mode, in spite of the significant stress compensation in the layers. The strong lattice microdistortion near the C atoms is likely the main reason of this effect.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"177 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132995577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Neubert, M. Seifert, P. Rudolph, K. Trompa, M. Pietsch
The purpose of this paper is to show the current stage of development of the Vapour Pressure Controlled Czochralski Method (VCZ) at the Institute of Crystal Growth (IKZ) in Berlin. First 3" s.i. GaAs crystals, grown in our laboratory, will be presented. The paper briefly summarizes investigations on i) crystal perfection i.e., etch pit density (EPD), cell structure, precipitates and, ii) electrical data, The properties of the crystals are acceptable for s.i. GaAs. An average EPD in the range from 1 to 2/spl times/10/sup 4/ cm/sup -2/ is just achieved but, does not yet match the requirements of very low EPD material.
{"title":"First results of s.i. GaAs single crystal growth applying the vapour pressure controlled Czochralski method","authors":"M. Neubert, M. Seifert, P. Rudolph, K. Trompa, M. Pietsch","doi":"10.1109/SIM.1996.570868","DOIUrl":"https://doi.org/10.1109/SIM.1996.570868","url":null,"abstract":"The purpose of this paper is to show the current stage of development of the Vapour Pressure Controlled Czochralski Method (VCZ) at the Institute of Crystal Growth (IKZ) in Berlin. First 3\" s.i. GaAs crystals, grown in our laboratory, will be presented. The paper briefly summarizes investigations on i) crystal perfection i.e., etch pit density (EPD), cell structure, precipitates and, ii) electrical data, The properties of the crystals are acceptable for s.i. GaAs. An average EPD in the range from 1 to 2/spl times/10/sup 4/ cm/sup -2/ is just achieved but, does not yet match the requirements of very low EPD material.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"174 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116332295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Kamiński, M. Pawłowski, R. Cwirko, M. Palczewska, R. Kozłowski
Deep levels in undoped semi-insulating (SI) GaAs and Fe-doped SI InP investigated by photoinduced transient spectroscopy (PITS). It is demonstrated that the resolution of this method can be improved by direct computer fitting of digitally recorded photocurrent decays.
{"title":"Characterisation of deep-level defects in semi-insulating GaAs and InP by high resolution photoinduced transient spectroscopy (HRPITS)","authors":"P. Kamiński, M. Pawłowski, R. Cwirko, M. Palczewska, R. Kozłowski","doi":"10.1109/SIM.1996.570926","DOIUrl":"https://doi.org/10.1109/SIM.1996.570926","url":null,"abstract":"Deep levels in undoped semi-insulating (SI) GaAs and Fe-doped SI InP investigated by photoinduced transient spectroscopy (PITS). It is demonstrated that the resolution of this method can be improved by direct computer fitting of digitally recorded photocurrent decays.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"26 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116215199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Comparisons have been made of the frequency dependence of the backgate admittance of GaAs structures prepared by MBE on undoped buffer layers prepared at high and low temperatures and of ion implanted structures. A model is offered to explain extra capacitive currents at low frequencies. Inductive and negative resistance behaviours which appear to be related have not been explained. None of these phenomena were apparent in the LT based structures.
{"title":"Observations of low frequency admittance between isolated GaAs structures formed by ion implantation and by epitaxy on epitaxial buffer layers prepared at high and low temperatures","authors":"F. Boroumand, A. Khalid, M. Hopkinson, J. Swanson","doi":"10.1109/SIM.1996.570876","DOIUrl":"https://doi.org/10.1109/SIM.1996.570876","url":null,"abstract":"Comparisons have been made of the frequency dependence of the backgate admittance of GaAs structures prepared by MBE on undoped buffer layers prepared at high and low temperatures and of ion implanted structures. A model is offered to explain extra capacitive currents at low frequencies. Inductive and negative resistance behaviours which appear to be related have not been explained. None of these phenomena were apparent in the LT based structures.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125292567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Rezzoug, F. Ducroquet, G. Guillot, L. Giraudet, J.P. Praseuth
Electron traps in AlInAs/In/sub .52/(Ca/sub 1-x/Al/sub x/)/sub .48/As (x=0.3) heterostructures are investigated by deep level transient spectroscopy. Two dominant traps with activation energies of 0.31 and 0.59 eV are observed in quaternary and ternary layers respectively. Both these levels are supposed to be intrinsic defects from the same origin. Another defect at E/sub c/-0.4 eV is detected at the AlInAs/InCaAlAs interface. The concentration of this trap is found to be non uniformly distributed on the wafer and possible impurity contamination is suggested.
{"title":"Deep trap characterization of Al./sub 48/In./sub 52/As/In/sub .52/(Ga/sub .7/Al/sub .3/)/sub .48/As heterostructures","authors":"K. Rezzoug, F. Ducroquet, G. Guillot, L. Giraudet, J.P. Praseuth","doi":"10.1109/SIM.1996.571102","DOIUrl":"https://doi.org/10.1109/SIM.1996.571102","url":null,"abstract":"Electron traps in AlInAs/In/sub .52/(Ca/sub 1-x/Al/sub x/)/sub .48/As (x=0.3) heterostructures are investigated by deep level transient spectroscopy. Two dominant traps with activation energies of 0.31 and 0.59 eV are observed in quaternary and ternary layers respectively. Both these levels are supposed to be intrinsic defects from the same origin. Another defect at E/sub c/-0.4 eV is detected at the AlInAs/InCaAlAs interface. The concentration of this trap is found to be non uniformly distributed on the wafer and possible impurity contamination is suggested.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128706960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The properties of InAlAs layers grown lattice matched to InP by molecular beam epitaxy (MBE) were investigated. For a large range of growth conditions (temperature, V/III beam equivalent pressure ratio, doping level), we have detected 3 deep electron trap families E1, E2, and E3 in the material bandgap. The presence of these traps give rise to a defect-assisted tunneling current in the space-charge region of Schottky diodes at low forward and reverse biases. The observed low frequency l/fl in reverse bias is interpreted in terms of fluctuations of the Schottky barrier height.
{"title":"Current-voltage and low frequency noise measurements on LT-InAlAs grown by MBE","authors":"C. Meva'a, P. Rojo-Romeo, X. Letartre","doi":"10.1109/SIM.1996.570932","DOIUrl":"https://doi.org/10.1109/SIM.1996.570932","url":null,"abstract":"The properties of InAlAs layers grown lattice matched to InP by molecular beam epitaxy (MBE) were investigated. For a large range of growth conditions (temperature, V/III beam equivalent pressure ratio, doping level), we have detected 3 deep electron trap families E1, E2, and E3 in the material bandgap. The presence of these traps give rise to a defect-assisted tunneling current in the space-charge region of Schottky diodes at low forward and reverse biases. The observed low frequency l/fl in reverse bias is interpreted in terms of fluctuations of the Schottky barrier height.","PeriodicalId":391894,"journal":{"name":"Proceedings of Semiconducting and Semi-Insulating Materials Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130681590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：