Heteroepitaxy of GaAs on CaF2/Si(111) By Surface Free Energy Modulation Method

Abstract

AbstractAn epitaxial GaAs layer was grown on a CaF2 (111) by means of surface free energy modulation of CaF2 by one-monolayer-height island formation. An additional low-temperature growth at a final stage of growth of the CaF2 layer on Si(111) produced high density islands whose height was one monolayer of CaF2. This surface structure contributed to enhance wettability of overgrown GaAs. Two-step growth sequence was also examined in order to grow GaAs layer on the modified CaF2/Si(111) with good crystallinity. The electron mobility of 2,000cm2/Vs in a Si doped GaAs layer (6×1017 cm−3) was obtained by the combination of the surface energy modulation method and the two-step growth method.