A semiconductor device according to the present disclosure includes a gate-all-around (GAA) transistor in a first device area and a fin-type field effect transistor (FinFET) in a second device area. The GAA transistor includes a plurality of vertically stacked channel members and a first gate structure over and around the plurality of vertically stacked channel members. The FinFET includes a fin-shaped channel member and a second gate structure over the fin-shaped channel member. The fin-shaped channel member includes semiconductor layers interleaved by sacrificial layers.