(The) electrical and optical characteristrics of carbon doped GaAs epilayers grown by low pressure MOCVD = 저압 유기금속화학증착법으로 성장한 탄소 도핑된 갈륨비소 에피층의 전기 및 광학적 특성

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The carbon (C) doping characteristics of GaAs epilayers have been investigated by varying the growth parameters of V/III ratio and growth temperature. Heavily carbon doped GaAs epilayers were obtained by reducing the V/III ratio down to 1 or using $CCl_4$ gas sources. All epilayers were grown by low-pressure and atmospheric-pressure metalorganic chemical vapor deposition (MOCVD). The temperature dependence of electrical properties of C doped GaAs epilayers have been investigated by Van der Pauw Hall analysis. The empirical relation of Hall mobility appropriate for C doped GaAs was obtained using the simple expression by Hilsum with some modified parameters. For C doped GaAs epilayers of p of $4.25\times{10^{19}}\;cm^{-3}$ and $1.01\times10^{20}\; cm^{-3}$, the mobilities were nearly constant at low temperature range ($T<100$ K), however they were decreased at high temperature range ($T>100$ K) due to optical phonon scattering. The temperature dependence of mobility has been analyzed using a simple analytical equation in degenerate limit and constant effective mass. There was no compensation in C doped GaAs epilayer of p of $4.25\times10^{19}\; cm^{-3}$, however there was a little compensation ($N_d/N_a=0.02$) in the epilayer with heavy doping concentration of $p=1.01\times10^{20}\; cm^{-3}$. The (400) diffraction peak of the C doped GaAs epilayer was splitted from the substrate GaAs peak. The measured angular separation was 191.25 arc sec for C doped GaAs with hole concentration of $9\times10^{19}\; cm^{-3}$. The lattice constant decreased with increasing the hole concentration due to strain by the incorporation of carbon, which has a smaller covalent radius than gallium and arsenic. The relationship between the hole concentration and the critical layer thickness ($L_c$) by the excess stress and Matthews- Blakeslee model was also discussed. It was calculated for both pure case and 10 \% compensated case. The excess stress model is more agreeable for C doped GaA...
Lee, Choo-ChonMin, Suk-Ki이주천민석기
Description
한국과학기술원 : 물리학과,
Publisher
한국과학기술원
Issue Date
1994
Identifier
68893/325007 / 000845514
Language
eng
Description

학위논문(박사) - 한국과학기술원 : 물리학과, 1994.2, [ v, 127, 8 p. ]

URI
http://hdl.handle.net/10203/47474