Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)最新文献

{"title":"The technology and applications of selective oxidation of AlGaAs","authors":"K. Choquette, K. Geib, H. Hou, D. Mathes, R. Hull","doi":"10.1109/SIM.1998.785109","DOIUrl":"https://doi.org/10.1109/SIM.1998.785109","url":null,"abstract":"Wet oxidation of AlGaAs alloys, pioneered at the University of Illinois a decade ago, recently has been used to fabricate high performance vertical-cavity surface emitting lasers (VCSELs). The superior properties of oxide-confined VCSELs has stimulated interest in understanding the fundamentals of wet oxidation. We briefly review the technology of selective oxidation of III-V alloys, including the oxide microstructure and oxidation processing as well as describe its application to selectively oxidized VCSELs.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127944803","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}

{"title":"The 1.1 eV deep level in 4H-SiC","authors":"W. Mitchel, R. Perrin, J. Goldstein, M. Roth, S.R. Smith, J. Solomon, A. Evwaraye, H. Hobgood, G. Augustine, V. Balakrishna","doi":"10.1109/SIM.1998.785126","DOIUrl":"https://doi.org/10.1109/SIM.1998.785126","url":null,"abstract":"Temperature dependent Hall effect and optical absorption measurements of vanadium doped semi-insulating 4H-SiC samples are reported along with optical admittance spectroscopy measurements of related material. In addition to the deep donor and acceptor levels of substitutional vanadium, E/sub C/-1.6 eV and E/sub C/-0.7 eV respectively, we report an additional level at 1.1 eV. This level has been seen in undoped 4H-SiC by optical admittance spectroscopy which has also detected a similar level at E/sub C/-1.0 eV in 6H-SiC, and by temperature dependent Hall effect in vanadium doped material. Optical absorption measurements of the vanadium intra-center absorption show that this level is not either of the two substitutional vanadium levels. SIMS measurements support the hypothesis that the 1.1 eV level is a complex of vanadium and another impurity, possibly titanium.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124525204","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}

{"title":"Stresses in 3C-SiC films grown on Si substrates","authors":"C. Jacob, P. Pirouz","doi":"10.1109/SIM.1998.785124","DOIUrl":"https://doi.org/10.1109/SIM.1998.785124","url":null,"abstract":"C-Sic films were grown epitaxially on Si(OO1) substrates by an atmospheric pressure chemical vapor deposition method. The stresses in the films were determined by Raman spectroscopy and compared to data from load-deflection measurements on similar films. The films are tensile as grown and have a stress of 0.3 GPa, which is lower than the reported values for similar films. A possible explanation for the lower stresses as well as other observed trends is suggested. A. Introduction In order for 3C-Sic films epitaxially grown on Si substrates to be used in devices, it is important that the stresses in the films be well understood and controlled, as these stresses determine the flatness and usability of these wafers, as well as other subsequent device characteristics. These stresses do not arise from the lattice mismatch of 20%, but rather from the thermal mismatch of 8% and other factors. The lattice mismatch is accommodated within the first monolayer by the formation of misfit dislocations. However, the thermal coefficient mismatch cannot be avoided and the stresses develop as the film-substrate system cools down after growth. While a number of explanations have been offered in the past for these stresses in chemical vapor deposition (CVD) grown films (l), there is no clear quantitative explanation that explains all the data. B. Experimental Results The films were grown in an atmospheric pressure CVD (APCVD) reactor and the details of the growth have been previously reported (2). The stresses were measured by micro- Raman spectroscopy and compared with data on films grown in the same reactor and measured by a load-deflection technique (3). The calculations of stress are based on the work of Feng et al. (4). It is well known that stresses cause a shift in the Raman peaks. These stresses can be estimated from the shifts in the LO (longitudinal optical) and TO (transverse optical) phonon positions. The peak positions for the films are tabulated in Table 1. From these values, the stress was determined. A stress of 0.3M0.2 GPa was measured in a 0.3 pm thick film grown in the APCVD reactor at 1360 \"C. This value of stress is lower than the values on similar films obtained by the load-deflection technique (3). These films were all grown in the same reactor under identical conditions. The resolution of the micro-Raman measurements was lower than that of the load deflection technique and that could explain the higher stress value measured by Raman spectroscopy. It has already been established in the SiC/Si system, that there are no stresses due to the film-substrate lattice mismatch, because of the presence of misfit dislocations with the appropriate spacing at the interface. Thus, any residual stresses are due to the thermal mismatch and other intrinsic stresses. The thermal mismatch stresses (of) can be calculated for each film orientation, using","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131294810","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}

{"title":"Stoichiometry-dependent vacancy formation in n-doped GaAs","authors":"J. Gebauer, M. Lausmann, R. Krause-Rehberg","doi":"10.1109/SIM.1998.785093","DOIUrl":"https://doi.org/10.1109/SIM.1998.785093","url":null,"abstract":"The formation of vacancies in n-doped GaAs with variable stoichiometry was studied by means of positron annihilation. Highly Te-doped (n=1.5-5/spl times/10/sup 18/ cm/sup -3/) GaAs samples were annealed at high temperatures under variable arsenic vapor pressure (p/sub As/) and rapidly quenched to room temperature. We found that monovacancies exist in Te-doped GaAs regardless of the annealing conditions. In contrast, the vacancy concentration was found to be dependent on p/sub As/, i.e. on the stoichiometry. The vacancy concentration increases like p/sub As//sup 1/4/ and saturates at high As pressures (3-6 bar). This is a proof that the dominant vacancies in Te-doped As-rich GaAs are related to Ga vacancies, in agreement to theoretical results. Moreover, the vacancies were independently identified by using the Doppler broadening coincidence technique.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128959815","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}

{"title":"High resolution EL2 and resistivity topography of SI GaAs wafers","authors":"M. Wickert, R. Stibal, P. Hiesinger, W. Jantz, J. Wagner, M. Jurisch, U. Kretzer, B. Weinert","doi":"10.1109/SIM.1998.785068","DOIUrl":"https://doi.org/10.1109/SIM.1998.785068","url":null,"abstract":"The mesoscopic inhomogeneity of LEC grown semi-insulating (SI) GaAs wafers has been investigated with EL2/spl deg/ absorption topography (EAT), photoluminescence topography (PLT), point contact topography (PCT) and contactless resistivity mapping (COREMA). Significant progress with respect to sensitivity of EAT and lateral resolution of COREMA has been achieved. High resolution topograms of wafers cut from ingots subject to standard and modified annealing procedures are presented. Direct comparison of EL2/spl deg/ and resistivity topograms reveals significant differences in the mesoscopic contrast and a contrast reversal for modified annealing. These observations can be explained very satisfactorily by assuming mesoscopic inhomogeneity of the intrinsic acceptor concentration which is modified during annealing. A model involving generation of Ga vacancies by dissolution of As/sub Ga/ antisites and gettering of the interstitial As at precipitates is presented and discussed.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125666502","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}

{"title":"Photoluminescence at 1.5 /spl mu/m of heavily Er-doped insulating films on Si","authors":"S. Lanzerstorfer, J. Pedarnig, R. Gunasekaran, D. Bauerle, W. Jantsch","doi":"10.1109/SIM.1998.785101","DOIUrl":"https://doi.org/10.1109/SIM.1998.785101","url":null,"abstract":"A comparison of the photoluminescence (PL) properties of Er-doped SiO/sub 2/, soda-lime glass, and ZBLAN glass films fabricated by pulsed-laser deposition (PLD) is given. The PL yield depends strongly on the host material. Under identical growth conditions and the same erbium concentrations in the targets, films deposited from the soda lime and ZBLAN glass show more than an order of magnitude higher luminescence yield. This enhancement is attributed to a higher concentration of optically active erbium in the multicomponent glass environment. Temperature quenching of the PL yield is observed for SiO/sub 2/:Er. The PL yield of soda-lime glass:Er and ZBLAN:Er increases with increasing temperature. A room temperature external quantum efficiency of 2/spl times/10/sup -4/ was obtained for Er-doped soda-lime glass.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115812012","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}

{"title":"Growth of GaN and AlGaN by high temperature vapor phase epitaxy","authors":"S. Fischer, F. Anders, M. Theis, G. Steude, T. Christmann, D. Hofmann, B. Meyer","doi":"10.1109/SIM.1998.785066","DOIUrl":"https://doi.org/10.1109/SIM.1998.785066","url":null,"abstract":"We investigated the influence of the growth temperature on high temperature vapor phase epitaxy of GaN. An almost direct proportionality between the growth rate and the Ga vapor pressure is observed. At optimum conditions growth rates as high as 210 /spl mu/m/h (T=1150/spl deg/c) are achieved. The maximum growth rate is believed to be limited by the supply of ammonia and the starting composition of GaN. Under optimum GaN growth conditions AlGaN layers were grown starting from previously alloyed Al-Ga as well as from co-evaporation of Ga and Al. Adding Al leads to a significant reduction of growth rate and increases the homogeneity of the layers. However, in almost all cases phase separation is found. Besides the binary GaN and AlN phases an intermediate AlGaN phase appears.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128929667","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}

{"title":"LT GaAs delta-doped with In: enhanced As excess, In-Ga intermixing, As cluster array ordering","authors":"N. Bert, V. Chaldyshev, A. Suvorova, N. Faleev, A. E. Kunitsyn, Y. Musikhin, V. Preobrazhenskii, M. A. Putyato, B. Semyagin, P. Werner","doi":"10.1109/SIM.1998.785083","DOIUrl":"https://doi.org/10.1109/SIM.1998.785083","url":null,"abstract":"The effects of indium incorporation in GaAs grown by MBE at low substrate temperature (LT GaAs) have been studied. The 0.04% indium doping is shown to provide an increase in the As excess along with improved crystal quality. The In-Ga intermixing is found to enhance by almost two orders of magnitude due to a high point defect concentration in LT GaAs. The effective activation energy of the intermixing is determined from TEM measurements to be 1.1 eV. The As precipitation kinetics is found to be quicker in In-free regions than within the In-containing layers. Using these observations, we successfully formed a 30 nm period perfect superlattice consisting of thin (double cluster diameter) As cluster sheets separated by cluster-free LT GaAs spacers.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127056624","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}

{"title":"Step-controlled epitaxial growth of SiC and its conductivity control","authors":"H. Matsunami, T. Kimoto","doi":"10.1109/SIM.1998.785122","DOIUrl":"https://doi.org/10.1109/SIM.1998.785122","url":null,"abstract":"Polytype-controlled epitaxial growth of SiC is achieved by utilizing step-flow growth on off-oriented SiC(0001) substrates. High-quality of SiC epilayers has been elucidated through photoluminescence, Hall effect, and deep level analyses. The background doping level of undoped epilayers can be reduced down to 0.5/spl sim/2/spl times/10/sup 14/ cm/sup -3/. In-situ n- and p-type impurity doping from the 10/sup 15/ to 10/sup 19/cm/sup -3/ range has been realized. In ion implantation of nitrogen donors and aluminum/boron acceptors, high-temperature annealing is a key issue to obtain nearly perfect electrical activation. Vanadium ion implantation can successfully be applied to form semi-insulating SiC layers.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128269518","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}

{"title":"TEM/HREM of Ti/Al and WNi/Ti/Al ohmic contacts for n-AlGaN","authors":"S. Ruvimov, Z. Liliental-Weber, J. Washburn, D. Qiao, Q. Lui, S. Lau","doi":"10.1109/SIM.1998.785117","DOIUrl":"https://doi.org/10.1109/SIM.1998.785117","url":null,"abstract":"High resolution and analytical transmission electron microscopy was applied to characterize the microstructure of Al/Ti and W/Al/Ti ohmic contacts to AlGaN/GaN HFET structures. Formation of a 15-25 nm thick interfacial AlTi/sub 2/N layer appears to be essential for ohmic contract behavior indicating a tunneling contact mechanism. Contact resistance was found to depend on the structure and composition of the metal and AlGaN layers, and on atomic structure of the interface. Contact resistivity increases with Al fraction in the AlGaN layer.","PeriodicalId":253421,"journal":{"name":"Semiconducting and Insulating Materials 1998. Proceedings of the 10th Conference on Semiconducting and Insulating Materials (SIMC-X) (Cat. No.98CH36159)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132475140","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}