Method of manufacturing a semiconductor device contact structure using lift

A method of manufacturing a contact structure in a semiconductor device utilizing lift-off for forming a submicron opening, comprising the steps of:

• forming an SiO.sub.2 layer on a semiconductor substrate;
• forming a negative resist layer sensitive to electron beams on said SiO.sub.2 layer;
• applying electron beams onto a predetermined region of said negative resist layer to draw a pattern thereon corresponding to said submicron opening to be formed;
• removing unnecessary portions of said negative resist layer by using a developer, thereby forming on a position where said submicron opening is to be formed a remaining pattern resist layer which consists of one layer and has a constant width substantially the same as that of said submicron opening;
• forming an Si.sub.3 N.sub.4 layer on the entire region of said SiO.sub.2 layer and said remaining pattern resist layer, said Si.sub.3 N.sub.4 layer being formed by sputtering such that said remaining pattern resist layer has a thickness five to ten times larger than that of said Si.sub.3 N.sub.4 layer;
• simultaneously removing said remaining pattern resist layer and that part of said Si.sub.3 N.sub.4 layer which is formed thereon, thereby forming said submicron opening in said Si.sub.3 N.sub.4 layer;
• dry-etching said SiO.sub.2 layer through said submicron opening using said Si.sub.3 N.sub.4 layer as a mask, so as to expose that region of said semiconductor substrate which corresponds to said submicron opening;
• and
• forming a metal electrode in said submicron opening and on said Si.sub.3 N.sub.4 layer such that it is brought into contact with said exposed region of said semiconductor substrate.