Method of manufacturing a semiconductor device

摘要

The present invention provides a method of manufacturing a semiconductor device to prevent the generation of crystalline defects due to shorting between interconnects resulting from etch residue as a result of the generation of vertical bird's beaks on top of the trench during field oxidation layer formation. The method includes forming an epitaxial layer over a semiconductor substrate, depositing a first SiO2 layer, an SiN layer and a second SiO2 layer in that order upon said epitaxial layer and forming a trench from the second SiO2 layer extending into the semiconductor substrate. A third SiO2 layer is formed coating said trench with a region of said third Si02 layer removed adjacent to said first SiO2 layer to expose a portion of said epitaxial layer within said trench. The trench is then filled with a first polysilicon layer to coat the third SiO2 layer and the first SiO2 layer followed by removal of the second SiO2 layer and the SiN layer and finally, the first SiO2 layer is oxidized to a depth extending into the trench corresponding to the exposed portion of the epitaxial layer so as to form a field oxide layer.