Formation of GaAs and Ga_1−xAl_xAs (0 ≤ x ≤ 0.3) layers on GaAs (111)A substrate by organometallic vapor phase epitaxy

Abstract

The GaAs and Ga 1−x Al x As (0 ⩽ x ⩽ 0.3) epitaxial growth on GaAs (111)A substrate was carried out by organometallic vapor phase epitaxy at total pressure ∼70 Torr. The regime of quantitative modulation of trimethyl gallium, Ga(CH 3 ) 3 , gas flow was applied to optimize the atomic ratio between A III and B V , while the tangential and normal parameters of the growth rate were comparable. Deposited GaAs and Ga 1−x Al x As (0 ⩽ x ⩽ 0.3) layers with crystallographic orientation of (111)A were obtained at ∼0.1-0.2 Torr of arsine, AsH 3 , pressure and low crystallization temperature ∼570-620 °C. Proposed optimization of the B V /A III relationship and reaction conditions resulted in a smooth surface of the deposited layers. Using the technological approach, a si-GaAs/n-GaAs:Si/p-GaAlAs:Zn/p + -GaAs:Zn hetero-structure was successfully synthesized. Structural and electrical properties of the prepared epitaxial structure were studied by high-resolution x-ray diffraction and electrochemical capacitance-voltage profiling. Obtained experimental results confirmed excellent crystal and interfacial quality as well as steep transitions in charge carrier concentration through the deposited layers.