SEMICONDUCTOR DEVICE FABRICATION METHOD FOR PREVENTING OUT-DIFFUSION OF IMPURITIES

摘要

PURPOSE: A semiconductor device fabrication method is to prevent impurities implanted into the semiconductor device during a subsequent process from being out-diffused, thereby enhancing the refresh capability in dynamic random access memory(DRAM). CONSTITUTION: A semiconductor device fabrication method comprises the steps of: providing a semiconductor substrate having a trench(110) and a pad oxide, an etch stopper layer of nitride layer and an anti-reflective coating(ARC) layer stacked in the named order on the semiconductor substrate except the trench region; forming a first oxide layer(112) of annealed oxy-nitride on the side walls and the bottom face of the trench; forming a trench liner(114) and a high temperature oxide(116) in the named order on the resultant substrate including the trench; forming a planarizing oxide layer(118) on the high temperature oxide such that the trench is filled; removing the planarizing oxide layer and the ARC layer by chemical mechanical polishing(CMP) and thereafter removing the etch stopper layer; and forming a gate oxide of oxy-nitride on the resultant semiconductor substrate.