METHOD FOR IMPROVING DEFECT CAUSED BY CHEMICAL MECHANICAL POLISHING USING HARD MASK

摘要

PURPOSE: A method is provided to effectively reduce Pinocchio defects caused by CMP(Chemical Mechanical Polishing) by using a dual hard mask including a nitride and oxide hard mask. CONSTITUTION: A gate oxide layer(11), a gate polysilicon, a WSix layer(12), a nitride hard mask(13) and an oxide hard mask(14) are sequentially stacked on a substrate(10). A BPSG layer(16) is deposited on the resultant structure. A plug contact is formed to expose the substrate. A polysilicon layer is deposited on the plug contact. By CMP the polysilicon layer using a basic slurry, a polysilicon plug(17) is formed.