A Schottky barrier diode is provided, which includes a semiconductor substrate, a first well region, an isolation region, a silicide layer and a silicon oxide-containing layer. The first well region of a first conductivity type is in the semiconductor substrate. The isolation region is in the first well region. The silicide layer is laterally adjacent to the isolation region, and over and in contact with the first well region. The silicon oxide-containing layer is over and in contact with the isolation region.