Abstract Heteroepitaxial growth of Si-based semiconductor materials has become an efficient method for high-performance group-IV and III-V optoelectronic and electronic devices. As-manufactured epi-ready Si wafers frequently retain molecular residues even after high-temperature thermal deoxidation. Consequently, additional surface conditioning can be required to achieve the cleanliness and morphology necessary for high-quality epitaxial growth. This study evaluates the effectiveness of Ar plasma pre-treatment for surface preparation of Si substrates, which is used as a platform for heteroepitaxial growth of group-IV and III-V materials in molecular beam epitaxy systems. In this paper, a brief Ar plasma exposure (3 minutes at 30 SCCM) effectively removed native oxides and preserved atomically smooth surfaces, with root-mean-square roughness below 0.25 nm. Ge layers grown on plasma-treated offcut Si substrates exhibited a threading dislocation density of 6.9 × 10 7 cm -2 , representing a ~55% reduction compared to non-treated substrates (1.3 × 10 8 cm -2 ). These findings demonstrate that Ar plasma pre-treatment provides a reliable and thermally efficient pathway for enhancing Si surface quality and supporting low-defect heteroepitaxial growth.
Zhang et al. (Mon,) studied this question.