Patent ID: 8274117

Claim:
A semiconductor device, comprising: a semiconductor substrate; a first MISFET having a channel of a first conduction type and formed on the semiconductor substrate; a second MISFET having a channel of a second conduction type that is opposite to the first conduction type and formed on the semiconductor substrate; an isolation region between the first MISFET and the second MISFET; a first film having a first strain, the first film covering a region where the second MISFET is disposed but not a region where the first MISFET is disposed; a second film having a second strain whose type is opposite to a type of the first strain, the second film covering the region where the first MISFET is disposed but not the region where the second MISFET is disposed; and an interlayer insulating film disposed on the first film and the second film; and a conductive plug extending through the interlayer insulating film over the isolation region; wherein the second film includes a first portion which has a first thickness, a second portion which is provided over the isolation region at a side closer to the second MISFET and has a second thickness being thinner than the first thickness, and a third portion which is provided over the first film and the isolation region, wherein the first film includes a fourth portion which has a third thickness being thicker than the second thickness.