Epitaxial growth of high purity GaAs in an argon atmosphere

Abstract

The epitaxial growth of high purity GaAs has been carried out successfully with a leak-free and corrosion resistant AsCl 3-Ga-Ar system. A background free carrier concentration of 7.35 × 10 12 cm -3, a mobility of 2.05 × 10 5 cm 2/V · s at 77 K, a peak mobility of 3.78 × 10 5 cm 2/V · s at 35 K and a thickness of 18.0 μm were achieved by careful control of growth conditions. The effects of deposition temperature on the growth rate and mobility at 77 K were investigated in H 2, N 2 and Ar systems respectively. It was found that the Ar system has an advantage over the N 2 system in growing high purity GaAs, especially in growing thinner epilayers. The residual impurities in high purity epilayers were investigated by IMMA and photoluminescence measurements. By these analyses one can see that the Si contamination is suppressed in the Ar system as effectively as in the N 2 system, and the dominat residual acceptor impurity of the high purity epilayer grown in the Ar system is carbon.