Semiconductor device

A semiconductor device, comprising:

• a substrate, comprising a pixel region and a logic region;
• a first gate structure comprising a first gate conductive layer over the substrate in the pixel region;
• a second gate structure comprising a second gate conductive layer over the substrate in logic region;
• a dielectric layer located on the substrate, the first gate structure and the second gate structure;
• a first contact located in the dielectric layer and electrically connected to the first conductive layer;
• a second contact located in the dielectric layer and electrically connected to the second conductive layer, wherein the first contact is different from the second contact, and the first contact comprises:
• a doped polysilicon layer in contact with the first conductive layer;
• a first metal layer located on the doped polysilicon layer, wherein a part of the first metal layer is embedded in the doped polysilicon layer;
• a first barrier layer located between the first metal layer and the doped polysilicon layer;
• and
• a first metal silicide layer located between the first barrier layer and the doped polysilicon layer.

A contact, comprising:

• a doped polysilicon layer embedded in a dielectric layer over and in contact with a polysilicon gate layer;
• a metal layer located on the doped polysilicon layer, wherein a bottom part of the metal layer is embedded in the doped polysilicon layer;
• a barrier layer located between a bottom surface of the metal layer and a top surface the doped polysilicon layer and located between a sidewall of the metal layer and the dielectric layer;
• and
• a metal silicide layer located between a bottom surface of the barrier layer and the top surface of the doped polysilicon layer.