Patent ID: 8071444
Filing Date: 2011-12-06
Classification: H01L

Abstract:
1. A method of manufacturing a nonvolatile semiconductor memory, comprising: forming a first insulating film on a semiconductor substrate; forming a first electrode layer, which becomes a charge accumulating layer, on the first insulating film; etching the first electrode layer, the first insulating film and the semiconductor substrate with prescribed gaps along a first direction, thereby forming a first trench; oxynitriding an inner wall and a bottom surface of the first trench; forming a buried insulating film where the first trench is buried; forming a second insulating film on the buried insulating film and the first electrode layer; forming a second electrode layer, which becomes a control gate electrode, on the second insulating film; forming a third insulating film on the second electrode layer; etching the third insulating film, the second electrode layer, the second insulating film and the first electrode layer with prescribed gaps along a second direction orthogonal to the first direction, thereby forming a second trench; oxidizing an inner wall of the second trench; and implanting an impurity into the semiconductor substrate, with the third insulating film serving as a mask, thereby forming an impurity dispersion region.