SEMICONDUCTOR SUBSTRATE AND METHOD FOR MANUFACTURING SEMICONDUCTOR SUBSTRATE

摘要

Disclosed is a high-quality GaAs crystalline thin film wherein a low-cost Si substrate having excellent heat dissipating characteristics is used. The semiconductor substrate is provided with a single crystal Si substrate, an insulating layer which is formed on the substrate and has an opening region, a Ge layer epitaxially grown on the substrate in the opening region, and a GaAs layer epitaxially grown on the Ge layer. The Ge layer is formed by introducing the substrate into a CVD reaction chamber which can be brought into an ultrahigh vacuum depressurized state, performing first epitaxial growth at a first temperature at which a material gas can be thermally decomposed, performing second epitaxial growth at a second temperature higher than the first temperature, performing first annealing to the epitaxial layer formed by the first and the second epitaxial growth, at a third temperature not reaching the melting point of Ge, and performing second annealing at a fourth temperature lower than the third temperature.