Provided is a semiconductor device, including a substrate including a pixel region, a gate structure on the substrate in the pixel region, wherein the gate structure comprises a gate dielectric layer and a gate conductive layer on the gate dielectric layer; a dielectric layer located over the substrate and the gate structure; and a contact located in the dielectric layer and electrically connected to the gate conductive layer. The contact includes a doped polysilicon layer in contact with the gate conductive layer; a metal layer located on the doped polysilicon layer, wherein a part of the metal layer is embedded in the doped polysilicon layer; a barrier layer located between the metal layer and the doped polysilicon layer; and a metal silicide layer located between the barrier layer and the doped polysilicon layer.