摘要 |
PROBLEM TO BE SOLVED: To effectively prevent diffusion of impurity, such as boron, by doping impurity, such as carbon, in a desired region with high accuracy during a growth step of silicon-germanium mixed crystal film. SOLUTION: When a silicon-germanium mixed crystal film is grown on a substrate 2 by introducing silicon raw gas, germanium raw gas, boron raw gas, and carbon raw gas to a reactive chamber 1, the carbon raw gas is introduced prior to the boron raw gas. The feeding timing of the carbon raw gas from a gas container 16 is prior to the feeding timing of the boron raw gas from a gas container 15, and thereby there is no gap between the taking-in of carbon and boron to the silicon-germanium mixed crystal film. In this way, the concentration of carbon is higher than that of boron in an arbitrary depth region of the silicon-germanium mixed crystal film, so that the diffusion of boron in a thermal process after formation of the base layer can be prevented effectively. COPYRIGHT: (C)2007,JPO&INPIT
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