Patent ID: 6756263
Filing Date: 2004-06-29
Classification: H01L,Y10S

Abstract:
A method of manufacturing a semiconductor device, comprising the steps of:forming a first oxide film on a main surface of a semiconductor substrate; forming a trench in an element-isolating region of said semiconductor substrate using said first oxide film as a mask; leaving said first oxide film on a first region while removing said first oxide film on a second region of said semiconductor substrate; forming an oxidation resistant film on said first oxide film left on said first region; forming a second oxide film on said second region with said first region covered with said oxidation resistant film; removing said first oxide film and said oxidation resistant film; forming a third oxide film on said first and second regions; forming a gate of a first transistor on said first region with said third oxide film interposed; and forming a gate of a second transistor on said second region with said second and third oxide films interposed.