METHOD FOR FABRICATING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a semiconductor device is provided to suppress dishing phenomena during CMP process for forming contact plug by performing second CMP using as acid slurry after finishing first CMP using base slurry. CONSTITUTION: A device-isolation layer is formed on semiconductor device to define active region. A gate oxide layer is formed on the whole surface of structure. A conducting layer for gate electrode composed of a doped poly silicon layer and a tungsten silicide layer is formed on the oxide layer. After forming a mask insulating layer, a mask insulating pattern and a conducting layer pattern for gate electrode are formed. A high temperature oxide(HTO) layer is formed after an insulating spacer is formed on the sidewall of the pattern. An interlayer dielectrics(27) is formed to flatten the whole surface. A conducting layer for contact plug is formed to bury a contact hole. The interlayer dielectrics and the conducting layer are flattened by the first CMP using base slurry ranging pH 6 to 12. Second CMP is performed until the mask insulating layer is exposed, using acid slurry ranging pH 0.5 to 2.