Method of fabricating a semiconductor device

A method for fabricating a semiconductor device having a contact plug, said method comprising the steps of:

• a first step of forming a polysilicon film and an insulation film on a semiconductor substrate, and then etching said polysilicon film and said insulation film to a prescribed shape, so as to form a gate electrode, after which an etching stopper is formed on substantially an entire surface of said substrate and an interlayer insulation film is formed over said entire surface thereof;
• a second step of forming a contact hole that reaches said semiconductor substrate in said interlayer insulation film, so as to cause a portion of said etching stopper on said semiconductor substrate to be exposed;
• a third step of removing substantially all of said exposed portion of said etching stopper on said semiconductor substrate;
• a fourth step of filling said contact hole to form a contact plug;
• a fifth step of removing substantially all a film that is deposited on said interlayer insulation film when said contact plug is formed, so as to expose said contact plug;
• a sixth step of etching substantially all of said interlayer insulation film and removing said etching stopper from at least a part of a top portion of said gate electrode;
• a seventh step of forming an interlayer insulation film over an entire surface of said substrate;
• an eighth step of etching said interlayer insulation film so as to expose at least a portion of said etching stopper on a diffusion layer of said semiconductor substrate and exposing at least a portion of said insulation film having said prescribed shape of said gate electrode, and etching said insulation film of said gate electrode to expose at least a portion of said polysilicon film, so as to form contact holes on said diffusion layer and said gate electrode;
• a ninth step of removing said etching stopper exposed on said diffusion layer;
• and a tenth step of filling said contact hole formed by said eighth step and said ninth step, so as to form said contact plugs.