| 摘要 |
PURPOSE:To prevent an epitaxial wafer from cambering and to reduce the crack loss due to the camber of the epitaxial wafer in the elementary process by a method wherein the camber of both of the surface and the back surface of the Si substrate are balanced. CONSTITUTION:A P-type Ge layer 23, a P-type GaAs layer 24 and an N-type GaAs layer 25 are formed on a thin type Si substrate 22 utilizing an MO-CVD method. Moreover, the front and back of the epitaxial wafer are inversed in the reactor by an MO-CVD method and an Al layer 21 is formed. As the linear expansibility of Al is larger compared to that of Si, the Al shrinks when the temperature in the reactor is returned to the room temperature after the formation of the Al electrode 21 and the Al layer 21 works so that the back surface of the Si substrate 22 roughens, while the GaAS layers 24 and 25 and a GaAlAs layer 26 work so that the surface of the Si substrate 22 roughens. As a result, the work of the GaAs layers 24 and 25 and the GaAlAs layer 26 and the work of the layer 21 are balanced so as to become the same degree, thereby enabling to prevent the camper of the epitaxial wafer. |
