Molecular beam epitaxy of gallium arsenide on 0.3°-misoriented epitaxial Si substrates

Abstract

APD (antiphase domain) free GaAs is grown by molecular beam epitaxy on an epitaxial (100)Si substrate with an offset angle of 0.3° without conventional high-temperature pretreatment. Reflection high energy electron diffraction (RHEED) demonstrates the presence of a double-domain reconstruction structure on the 0.3° misoriented Si substrate after pretreatment at 400–600°C. However, the GaAs epitaxial layers grown on these substrates by the two-step method were APD free. KOH etching and double crystal X-ray diffraction (DCXD) show the crystalline quality of GaAs grown on the epitaxial Si substrate is comparable to that of GaAs grown on conventional Si substrates heat-treated at 900°C. The evaluation by atomic force microscopy (AFM) shows the surface flatness of GaAs layer grown on the 0.3°-misoriented epi-substrate is much more superior to that grown on the epi-substrate with 2° offset.