| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device, capable of preventing etching residue of a semiconductor layer, when forming a back gate structure or a double gate structure on a semiconductor substrate by the SBSI method. SOLUTION: By having the germanium concentration of a first SiGe layer 12a, formed on a semiconductor substrate 11, set up lower than the germanium concentration of a second SiGe layer 13a formed in the upper part, the etching rates of the first SiGe layer 12a and the second SiGe layer 13a are made almost the same. With such a composition, while high-speed etching of Si layer is prevented, the etching residue of the SiGe layer 13a and the like, selective etching is made possible in the SiGe layers 12a and 13a of multilayer structure. COPYRIGHT: (C)2008,JPO&INPIT
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