| 摘要 |
PROBLEM TO BE SOLVED: To prevent the mixture of a carrier producing impurity in a spacer layer on an area containing the impurity at a high concentration caused by the residual partial pressure of a dopant gas. SOLUTION: In an HCMOS, an n-type SiGe heavily-doped layer 4, an SiGe spacer layer 5, and an Si n-channel layer 6 are provided in this order on an SiGe buffer layer 3. The percentages composition of Ge in the buffer layer 3 and spacer layer 4 are 10% and that of Ge in the heavily-doped layer 4 is 20%. Since the impurity concentration in an SiGe layer can be reduced to about 1/5, when the percentage composition of Ge in the layer is reduced to 10% from 20%, the concentration of a carrier producing impurity in the spacer layer 5 can be reduced.
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