| 摘要 |
The present invention is a method for producing a semiconductor substrate, including steps of forming a SiGe gradient composition layer and a SiGe constant composition layer on a Si single crystal substrate, flattening a surface of the SiGe constant composition layer, removing a natural oxide film on the flattened surface of the SiGe constant composition layer, and forming a strained Si layer on the surface of the SiGe constant composition layer from which the natural oxide film has been removed, wherein the formation of the SiGe gradient composition layer and the formation of the SiGe constant composition layer are performed at a temperature T1 that is higher than 800° C., the removal of the natural oxide film from the surface of the SiGe constant composition layer is performed in a reducing atmosphere through a heat treatment at a temperature T2 that is equal to or higher than 800° C. and lower than the temperature T1, and the formation of the strained Si layer is performed at a temperature T3 that is lower than the temperature T1. This method enables epitaxial growth of the strained Si layer on the flattened SiGe layer without degrading surface flatness of the SiGe layer. |
