Patent ID: 8748279

Claim:
A method of manufacturing a semiconductor device, comprising the steps of: forming an isolation trench in a semiconductor substrate; depositing a layer of an insulating material on the semiconductor substrate; removing the insulating material from the semiconductor substrate, the insulating material remaining in the isolation trench; forming a gate oxide on the semiconductor substrate; depositing a poly-silicon layer on said gate oxide; causing said silicon layer to become planar by performing a chemical mechanical planarization processing on said poly-silicon layer, comprising applying a grinding head having a down force of from about 1 psi to about 3 psi, and a rotating platen having a rotating speed of from 50 rpm to 110 rpm, using a CeO 2 based slurry for grinding having a mass concentration of less than 40% CeO 2 ; cleaning the surface of said poly-silicon layer; and forming a poly-silicon gate with said poly-silicon layer, wherein said cleaning comprises: cleaning the surface of said poly-silicon layer using an alkaline solution having a temperature higher than 60 degrees centigrade, thereby removing particles remaining on the surface of said poly-silicon layer.