Patent ID: 8394693

Claim:
A method for manufacturing a semiconductor device, comprising: forming a first MISFET having a channel of a first conduction type in a first active region of a semiconductor substrate; forming a second MISFET having a channel of a second conduction type that is opposite to the first conduction type in a second active region that is separated from the first active region in an in-plane direction; forming a first film having a strain on the semiconductor substrate so as to cover the first MISFET and the second MISFET; patterning the first film such that the first film in a region where the first MISFET is disposed is removed and the first film in a region where the second MISFET is disposed is left; forming a second film having a strain that is opposite to the first, over the semiconductor substrate so as to cover the first MISFET and the patterned first film; thinning an exposed portion of the second strain film by etching the exposed portion to an intermediate position in a thickness direction of the second film, using a first mask pattern that covers the region where the first MISFET is disposed but not the region where the second MISFET is disposed; and removing the second film in the region where the second MISFET is disposed, using a second mask pattern that covers the region where the first MISFET is disposed but not the region where the second MISFET is disposed, after thinning a part of the second film, wherein one of the first mask pattern and the second mask pattern overlaps with at least a part of an edge of the patterned first film and the other one of the first mask pattern and the second mask pattern is separated from the edge in an in-plane direction; and wherein, when removing the second film in the region where the second MISFET is disposed, the second film is removed such that a part of the second film is left in a region that has been covered with only one of the first mask pattern and the second mask pattern.