Patent ID: 6235626
Filing Date: 2001-05-22
Classification: H01L

Abstract:
A method of forming a gate recess in an insulating film on a substrate for depositing a gate electrode film being in contact with a part of said substrate and also extending at least within said gate recess, said method comprising the steps of:forming an etching mask pattern with a first opening pattern on said insulating film;carrying out a first anisotropic etching process by use of said etching mask pattern at a first selective ratio of said etching mask pattern to said insulating film, thereby to form a first recessed portion having a bottom which lies at a first level higher than an interface level between said insulating film and said substrate; andcarrying out a second anisotropic etching process by use of said etching mask pattern again at a second selective ratio of said etching mask pattern to said insulating film, wherein said second selective ratio is higher than said first selective ratio, thereby to form a gate recess which comprises a second recessed portion both having a bottom which lies at said interface level and having first side walls of a first oblique angle and a third recessed portion both having a bottom united with a top of said second recessed portion and having second side walls of a second oblique angle which is smaller than said first oblique angle.