Two-step silicidation process for fabricating a semiconductor device

摘要

A two-step silicidation process for fabricating a semiconductor device is disclosed. The method includes the following steps. Firstly, two trench isolation regions are formed in a semiconductor substrate. A gate oxide layer and a polysilicon layer and a barrier layer are formed. Patterning is carried out to etch portions of the barrier layer. The areas between the trench isolation regions and the gate region are respectively used as a source area and a drain area. First ions are implanted into the substrate. A dielectric layer is blanket formed and the dielectric layer is etched back to form dielectric spacer. The second ions are implanted into the substrate. The first silicide regions respectively are formed in the source area and the drain area. A poly-metal dielectric (PMD) layer is formed and is etched back. Finally, the second silicide region is formed on and in the polysilicon layer.