Initial Stage and Domain Structure of GaAs Grown on Si(100) by Molecular Beam Epitaxy

Abstract

The initial stage of GaAs epitaxial growth on Si(100) has been studied by RHEED and AES. On exposure to a As₄ flux, the Si surface is covered with one or two monolayers of As which are stable up to 700°C, while Ga on Si desorbs even at 500°C. There are two kinds of Si-As reconstruction, which depend on the temperature of Si exposed to As₄ flux. One is 1×2 for high temperature (>600°C) and the other is 2×1 for low temperature (<450°C) when the Si substrate has 2×1 reconstruction. The surface reconstructions of GaAs grown on Si(100)-As 1×2 and Si(100)-As 2×1 are perpendicular to each other, which indicates that the domain direction of GaAs to Si substrate is different depending on the initial growth temperature.