Mechanism of arsenic incorporation growth of gallium arsenide on gallium-covered surfaces

Abstract

Thin-film crystal growth of GaAs induced by the incorporation of As on Ga-covered GaAs surfaces was studied using two kinds of As sources, AsH3 and As4. The period required for completing the incorporation growth was investigated as a function of the As flux as well as of the substrate temperature. In order to measure the growth period, completion of incorporation growth was detected through a phase change in the surface reconstruction observed in the reflection high-energy electron-diffraction (RHEED) pattern. Further, the growth rate was obtained by dividing the growth thickness by the growth period. It is found that the As flux dependence of the growth rate is linear for the case of AsH3 while it is super-linear for the As4 case. The temperature dependence of the growth rate is explained as the result of competitive processes of the incorporation and desorption of As2 on the surface when AsH3 is used as the As source. © 1992.