WAFER AND ITS MANUFACTURING METHOD, AND SEMICONDUCTOR SUBSTRATE AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a method for manufacturing a wafer by which the characteristic of an epitaxial film formed on the surface of the wafer can be made uniform and appropriate. SOLUTION: The method is used to manufacture a wafer 10 so that an epitaxial film is formed on its surface 11A. It includes a preparation step to prepare a wafer 15 whose front surface 15A and rear surface 15B are made flat; a convex-part formation step wherein a central convex 19 with a projecting central area is formed on the surface of the wafer prepared in the preparation step, and a peripheral convex 20 with a projecting peripheral area is formed on the rear surface thereof; and a grinding step wherein a pressure F is given to the front surface 18A and the rear surface 18B of the wafer 18 processed in the convex formation step, so as to cause any distortion in the wafer 18 and the front and rear surfaces are ground flat. The side of the front surface 11A has a convex bending shape, and when the wafer 10 is heated to form an epitaxial film on the front surface 11A, it is deformed and becomes flat. COPYRIGHT: (C)2007,JPO&INPIT