| abstract |
The present invention provides a semiconductor substrate and a method of making the same, whereby a GaAs family crystalline thin film with great quality is obtained by using inexpensive Si substrate with excellent heat dissipation feature. The semiconductor substrate comprises a single crystal Si substrate, an insulation layer disposed upon the substrate with an opened area, a Ge layer epitaxially grown upon the substrate of the opened area, and a GaAs layer epitaxially grown upon the Ge layer, wherein the Ge layer is formed by introducing a substrate into a CVD reaction chamber that can reach a decompression state of ultrahigh vacuum, performing a first epitaxial growth at a first temperature that can pyrolyze material gas, performing a second epitaxial growth at a second temperature that is higher than the first temperature, performing a first anneal upon an epitaxial layer performed with the first and the second epitaxial growth at a third temperature that does not reach Ge's melting point, and performing a second anneal at a fourth temperature that is higher than the third temperature. |