Metal Oxide Semiconductor Device and Method for Manufacturing the Same

A Metal Oxide Semiconductor device includes a semiconductor substrate; a gate electrode formed on the surface of the substrate, having an offset spacer on each side; source/drain electrodes in the substrate having lightly doped regions respectively; metal silicide located on the gate electrode and the source/drain electrodes; and first impurity ions and second impurity ions in the lightly doped regions. A method for manufacturing a Metal Oxide Semiconductor device includes forming a gate electrode on a semiconductor substrate; implanting first impurity ions and second impurity ions to form lightly doped regions; depositing a dielectric layer and etching the dielectric layer to form offset spacers; implanting the first impurity ions to form the source/drain electrodes; forming metal silicide on the surfaces of the gate electrode and the source/drain regions. This invention can effectively prevent metal nickel diffusion into the lightly doped regions.