Download or read book Study of Grown In Defects Verses Growth Parameters in GaAs and Al x Ga 1 x AS Epitaxial Films Grown by LPE and MOCVD Techniques written by Sheng S. Li and published by . This book was released on 1985 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model for describing the physical origins of the EL2 center in the GaAs is presented based on the kinetic reaction equations and the analysis of electric-field enhanced emission rates for the four different types of potential well. It has been shown that the EL2 center may be ascribed to two different types of native defect: One level (E sub c-0.83 eV) attributing to the antisite defect, As sub Ga or the antisite cluster, As sub Ga-As4 is designated as the EL2a electron trap, and the other level (E sub c-0.76 eV) attributing to the antisite-vacancy complex, As sub Ga-VAs is designated as the EL2b electron trap. The EL2a electron trap was found to be strongly dependent on the growht condition, e.g., AsH3/TMGa ratio, growth temperature growth rate(mainly at lower growth rate) and buffer layer. Second, the final transition state of electron emission from the DX center to the nonspherical conduction band minima in A1xGa1-xAs has been studied by capacitance-Voltage measurement and Deep level Transient Spectroscopy experiment. The results indicate that the conduction band minimum associated with the electron emission is the L band instead of the band which is the lowest conduction band. Analysis of th eelectric-field enhanced emission rate applied to the Coulombic and Yukawa potential well has further supported the fact that emission and capture of electron from the DX center is related to the L minimum in the conduction band.
Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1987 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1987 with total page 1256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1987 with total page 1260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1987 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metals Abstracts written by and published by . This book was released on 1982 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1989 with total page 874 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Corporate author written by and published by . This book was released on 1987 with total page 1028 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Growth In Defects and Transport Properties Versus Growth Parameters in III V Compound Semiconductors written by Sheng S. Li and published by . This book was released on 1982 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this research project are: (1) to investigate the grown-in deep level defects vs. growth parameters (e.g., growth temperature, growth rate, Ga/As ratio, and substrate orientations) in GaAs epilayers grown by liquid phase epitaxial (LPE) and vapor phase epitaxial (VPE) techniques, (2) to study the transport properties vs. growth parameters in the LPE and VPE grown GaAs, and (3) to study the effects of combined thermal and injection annealing on the grown-in defects in the VPE GaAs epilayers.
Download or read book Study of Grown in Defects and Radiation induced Defects in GaAs and AlxGa1xAs written by Weng-Lyang Wang and published by . This book was released on 1984 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this dissertation are (1) to conduct a detailed analysis of the grown-in defects and radiation induced defects in GaAs grown by the LEC, VPE, LPE, and MOCVD techniques under different growth and annealing conditions, (2) to identify the physical origins of the deep-level trap in GaAs, and (3) to determine the potential well of electron traps from analyzing the electric field enhanced emission rates deduced from the non-exponential DLTS data. A detailed theoretical and experimental study of the grown-in defects and radiation- induced defects in GaAs has been carried out in this dissertation; the main research accomplishments derived from this research are summarized as follows: (1) Theoretical and experimental studies of native point defects in GaAs grown by the LEC, VPE, LPE, and MOCVD techniques under different growing and annealing conditions have been made in this research, and the conclusions are listed as follows: (a) high purity GaAs material can be grown for the low arsenic pressure case under optimum cooling condition, (b) GaAs grown under a high arsenic pressure condition will produce more native point defects than lower xi arsenic pressure conditions, (c) arsenic antisite (AS--O defect only can be observed in GaAs grown under an As-rich or high arsenic pressure conditions; this defect can not be produced under low arsenic pressure condition. (2) A new defect model supported by the experimental data has been developed in this work to account for the physical origins of the EL2 electron trap in GaAs. It is shown that the EL2 electron trap may be attributed to two different types of native defects: One is identified as the EL2a (i.e., Ec-0.83eV) electron trap, and the other is designated as the EL2b (Ec-0.76eV) electron trap. The physical origin for the EL2a level is attributed to the doubly-charged arsenic antisite (i.e., AsGg ++) defect, whereas the physical origin for the EL2b electron trap is due to the arsenic-anti site-plus-arsenic vacancy complex (ie., AsGaV,). Based on this model, the relationship between the density of EL2a and EL2b trap levels and the As/Ga ratio in the MOCVD and VPE grown GaAs was established. (3) A theoretical model for the non-exponential DLTS response due to the field dependent emission rate of the trapped charge has been developed. A comparison of the theoretical calculation of the non-exponential DLTS response with the DLTS data for each trap level would allow us to determine the potential well of the trap involved. This method has been applied to identify the physical origins of the EL2a electron trap in GaAs.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science Abstracts written by and published by . This book was released on 1995 with total page 1990 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Growth Mechanisms and Electrical and Optical Properties of Epitaxial Al x Ga 1 x N Layers Grown by Atmospheric Pressure Metalorganic Chemical Vapor Deposition written by Keyvan Rahim Sayyah and published by . This book was released on 1986 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Epitaxial Crystal Growth written by E. Lendvay and published by Trans Tech Publications Ltd. This book was released on 1991-01-01 with total page 979 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 1st International Conference on Epitaxial Crystal Growth, Budapest, Hungary, April 1990
Download or read book Microstructural Investigation of Defects in Epitaxial GaAs Grown on Mismatched Ge and SiGe Si Substrates written by Boeckl John J. and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this dissertation we report on the structural quality of the GaAs/Ge interface for GaAs nucleation by solid source molecular beam epitaxy (MBE). Through feedback from these characterizations, optimized growth methods are established, demonstrating the ability to grow defect-free epitaxial GaAs films on Ge substrates. We also present data on the electrical activity associated with defects that result if the growth is not fully controlled. In theses studies we exploit a novel use of an electron beam induced current (EBIC) technique to show the electrical activity associated with anti-phase domains and inter-diffusion from regions as small as 100 nm. Integrating this GaAs MBE nucleation methodology on the SiGe graded substrates we show that the GaAs stoichiometry and material properties transfer without degradation from the higher threading dislocation density of the SiGe substrates. In these studies we show that fundamental defects such as; threading dislocation, anti-phase domains, and atomic inter-diffusion are controlled to a level that enables growth of extremely high quality GaAs device layers. Combined with the low TDD enabled by the SiGe graded buffer, record GaAs/Si minority carrier lifetimes in excess of 10 ns have been achieved. However, other larger scale defects are shown to have a limiting effect on large area device performance. One such morphological surface defect, known as the "bat", is generated during the UHVCVD SiGe growth. The defect was comprehensively studied and results indicate that the impact on GaAs device performance was due to dislocation clusters in MBE device layers. Comparison analysis with GaAs overgrowth via metal organic chemical vapor deposition (MOCVD) demonstrated this growth method produced fully-operational large-area device structure. A model relating surface growth rates to an incomplete lattice-mismatch relaxation predicts the formation of these clusters. While challenges remain for monolithic III/V optoelectronic integration on Si, it is clear that the demonstration of successful GaAs nucleation on the SiGe substrate represents a significant milestone on the path to the final goal of truly integrated III-V devices with Si integrated circuits.
