Patent ID: 7767548

Claim:
A method for manufacturing a semiconductor wafer, comprising: (a) forming a SiGe mixed crystal layer and a first Si layer in this order on a surface of a silicon wafer; (b) forming a SiO 2 layer on top of the first Si layer, on a separately prepared support wafer which is prepared separately from the first Si layer, or on the first Si layer and the support wafer; (c) forming a layered product by stacking the silicon wafer and the support wafer with the SiO 2 layer being placed therebetween; (d) forming a second Si layer by thinning the silicon wafer of the layered product to a predetermined thickness; (e) implanting hydrogen ions, rare gas ions, or both hydrogen ions and rare gas ions, to form ionic concentration peaks in an area which includes an interface between the first Si layer and the SiO 2 layer, and also includes the first Si layer from the interface up to one half a thickness thereof; (f) carrying out a first heat treatment by maintaining the layered product in an inert gas atmosphere containing nitrogen or Argon gas at 450 to 600° C. for 15 to 600 minutes; and (g) carrying out a second heat treatment following the first heat treatment, by maintaining the layered product at 800 to 1000° C. for 15 to 300 minutes, thereby relaxing the SiGe mixed crystal layer and diffusing Ge through portions of the first Si layer and the second Si layer.