Method for forming an electrode of semiconductor device capacitor

A method for forming an electrode of semiconductor device capacitor is disclosed. The method comprises forming a dielectric layer on a semiconductor substrate and then using photolithographic method to etch a trench through the dielectric layer to expose specific part of the semiconductor substrate. A polysilicon layer is then formed over the dielectric layer and filled the trench. The polysilicon layer is patterned by a photoresist layer and etched back to the dielectric layer, then a polysilicon rod is formed. A spacer method is used to form an amorphized silicon spacer is sidewall of the polysilicon rod. The polysilicon rod is then implanted to form an amorphized polysilicon layer on top surface of the polysilicon rod. Final hemispherical grain silicon is formed on the spacer and the amorphized polysilicon layer to increase the surface area of the polysilicon rod. Thereby, an electrode of a semiconductor device capacitor is formed, and the capacitance of capacitor is enhanced.