A semiconductor device includes a plurality of first cells having a first cell height, and a plurality of second cells having a second cell height. Each of the first cells has a first MIS transistor of a first conductivity type, and a substrate contact region of a second conductivity type. Each of the second cells has a second MIS transistor of the first conductivity type, a power supply region of the first conductivity type, and a first extended region of the first conductivity type that is silicidated at a surface thereof. The first cell height is greater than the second cell height.