| 摘要 |
The selective growth of a semiconductor film is disclosed while preventing concentrations at the time of a growth of a SiGe epitaxial layer to form a SiGe layer free from defects. In a UHV-CVD apparatus, after a substrate for growth is fitted, a substrate temperature is set to 650 DEG C, disilane is irradiated onto a surface of the substrate, and the irradiation is finished before Si clusters are formed on an oxide film. Chlorine is irradiated, thereby removing Si atoms on the oxide film. These steps are repeatedly performed, thereby forming a Si epitaxial layer. The substrate temperature is lowered to 550 DEG C, irradiation of disilane and germane and irradiation of chlorine are repeatedly performed, thereby forming a SiGe epitaxial layer. While keeping the substrate temperature at 550 DEG C, disilane is irradiated, thereby forming Si cover layer. The substrate temperature is elevated to 650 DEG C and the a Si epitaxial layer is formed by the same steps as those for the formation of the former Si epitaxial layer. The epitaxial step is repeatedly performed similarly, thereby forming a Si/SiGe super lattice structure. <IMAGE> |
