US Patent 7800202 Semiconductor device

In order to obtain substantially the same operating speed of a p-type MOS transistor and an n-type MOS transistor forming a CMOS circuit, the n-type MOS transistor has a three-dimensional structure having a channel region on both the (100) plane and the (110) plane and the p-type MOS transistor has a planar structure having a channel region only on the (110) plane. Further, both the transistors are substantially equal to each other in the areas of the channel regions and gate insulating films. Accordingly, it is possible to make the areas of the gate insulating films and so on equal to each other and also to make the gate capacitances equal to each other.