METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device capable of controlling a film thickness of a silicon layer in a channel region without adding an extra step.SOLUTION: A method for manufacturing a semiconductor device comprises steps of: forming a silicon layer 12 on a semiconductor substrate 31 including a first and a second region by an epitaxial growth method; forming a gate oxide film 16 by oxidizing the silicon layer; removing the first gate oxide film in the second region while leaving the first gate oxide film in the first region; thickening the first gate oxide film in the first region and forming a second gate oxide film 18 by oxidizing the silicon layer in the second region; and forming a first gate electrode on the first gate oxide film and a second gate electrode on the second gate oxide film. After the first gate electrode and the second gate electrode are formed, the silicon layer 12 in the first region includes a first film thickness, and the silicon layer 22 in the second region includes a second film thickness thinner than the first film thickness.