METHOD FOR FABRICATING SEMICONDUCTOR STRUCTURES

摘要

High quality epitaxial layers of monocrystalline materials (26) can be grown overlying monocrystalline substrates (22) such as large silicon wafers by forming a compliant substrate for growing the monocrystalline layers. An accommodating buffer layer (24) comprises a layer of monocrystalline oxide spaced apart from a silicon wafer by an amorphous interface layer (28) of silicon oxide. The amorphous interface layer dissipates strain and permits the growth of a high quality monocrystalline oxide accommodating buffer layer. The accommodating buffer layer is lattice matched to both the underlying silicon wafer and the overlying monocrystalline material layer. Any lattice mismatch between the accommodating buffer layer and the underlying silicon substrate is taken care of by the amorphous interface layer. The surface of the underlying silicon wafer is prepared by the controlled growth and subsequent reduction of a surface oxide, and then by properly reconstructing the silicon surface by the deposition of a thin layer of an alkaline earth metal. Monocrystalline growth of the accommodating buffer layer is enhanced by an interrupted growth procedure.