Patent ID: 8753962

Claim:
A method for producing an epitaxial wafer by epitaxially growing a silicon layer on a surface of a silicon wafer, the method comprising: using a mixed gas of trichlorosilane and dichlorosilane as source gas, and epitaxially growing the silicon layer within a temperature range of 1000 to 1100° C.; and preventing a haze level of the resulting epitaxial wafer from getting worse than a haze level of polished wafer, and making the resulting epitaxial wafer excellent in flatness; and the temperature region of the epitaxial growth is set in the range of 1040 to 1080° C., the haze level of the resulting epitaxial wafer is controlled in the range of 0.050 to 0.080 ppm when measured in DWN mode using a KLA-Tencor particle counter (SP-1), and the flatness is improved so that edge roll-off is within a range of −20 nm to +20 nm, and when the orientation dependence of epitaxial growth rate is evaluated with a film thickness of an epitaxial layer along an orientation of 45° relative to reference crystal orientation, given that a film thickness of the epitaxial layer along reference crystal orientation be taken as 1, the film thickness of the epitaxial layer along the orientation of 45° is controlled to be 0.985 or more.