Patent ID: 6034393
Filing Date: 2000-03-07
Classification: H01L

Abstract:
A nonvolatile semiconductor memory device using trench isolation, comprising:a silicon semiconductor substrate;a trench for said trench isolation formed as a line in a main surface of said semiconductor substrate;a first insulating film provided on said semiconductor substrate to fill said trench;a first gate electrode provided on said semiconductor substrate on both sides of said trench with a first oxide film interposed; anda second gate electrode formed on said first gate electrode with a second insulating film interposed therebetween; whereinan angle formed by a side wall surface of said trench and an upper surface of said semiconductor substrate is smaller than 90.degree. C.; andsaid first oxide film is formed of SiO.sub.x N.sub.y or a material containing SiO.sub.x N.sub.y.