A method of fabricating a semiconductor device includes the following steps. A substrate is provided. The substrate includes a pixel region having a first conductive region and a logic region having a second conductive region. A dielectric layer is formed on the substrate to cover the first conductive region. A first contact opening is formed in the dielectric layer to expose the first conductive region. A doped polysilicon layer is sequentially formed in the first contact opening. A first metal silicide layer is formed on the doped polysilicon layer. A second contact opening is formed in the dielectric layer to expose the second conductive region. A barrier layer and a metal layer are respectively formed in the first contact opening and the second contact opening.