Method of manufacturing semiconductor device

Claim 1

A method of manufacturing a semiconductor device comprising the steps of: forming on a semiconductor substrate a first interconnection pattern and a second interconnection pattern adjacent to each other, each with a first oxide film formed thereon; forming a second oxide film on said semiconductor substrate to cover sidewalls of said first and second interconnection patterns; forming a silicon nitride film as an etching stopper to cover said first and second interconnection patterns with said first and second oxide films interposed therebetween; forming an interlayer insulating film on said semiconductor substrate to cover said silicon nitride film; etching, using a resist pattern, a portion of said interlayer insulating film located between said first interconnection pattern and said second interconnection pattern until a surface of said silicon nitride film is exposed, to form a contact hole; removing said resist pattern; and dry-etching in a self-aligned manner a bottom of said contact hole employing mixed gas plasma containing CH 2 F 2 and O 2 with a mixture ratio of said O 2 to said CH 2 F 2 between 25 and 40%, to expose a surface of said semiconductor substrate.

Claim 2

A method of manufacturing a semiconductor device comprising the steps of: forming on a semiconductor substrate a first interconnection pattern and a second interconnection pattern adjacent to each other, each with a first oxide film formed thereon; forming a second oxide film on said semiconductor substrate to cover sidewalls of said first and second interconnection patterns; forming a silicon nitride film as an etching stopper to cover said first and second interconnection patterns with said first and second oxide films interposed therebetween; forming an interlayer insulating film on said semiconductor substrate to cover said silicon nitride film; etching, using a resist pattern, a portion of said interlayer insulating film located between said first interconnection pattern and said second interconnection pattern until a surface of said silicon nitride film is exposed, to form a contact hole; removing said resist pattern; and dry-etching in a self-aligned manner a bottom of said contact hole employing mixed gas plasma containing CH 2 F 2 and O 2 with a mixture ratio of said O 2 to said CH 2 F 2 between 25 and 40%, to expose a surface of said semiconductor substrate.

Claim 6

A method of manufacturing a semiconductor device, comprising the steps of: forming on a semiconductor substrate a first interconnection pattern and a second interconnection pattern adjacent to each other, each with a first oxide film formed thereon; forming a second oxide film on said semiconductor substrate to cover sidewalls of said first and second interconnection patterns; forming a silicon nitride film as an etching stopper to cover said first and second interconnection patterns with said first and second oxide films interposed therebetween; forming an interlayer insulating film on said semiconductor substrate to cover said silicon nitride film; etching, using a resist pattern, a portion of said interlayer insulating film located between said first interconnection pattern and said second interconnection pattern until a surface of said silicon nitride film is exposed, to form a contact hole; removing said resist pattern; etching said silicon nitride film at a bottom of said contact hole in a self-aligned manner to expose a surface of said second oxide film; and etching said second oxide film at the bottom of said contact hole in a self-aligned manner by setting etch selectivity of said first oxide film to said silicon nitride film to at most 1, to expose a surface of said semiconductor substrate.

Claim 7

A method of manufacturing a semiconductor device, comprising the steps of: forming on a semiconductor substrate a first interconnection pattern and a second interconnection pattern adjacent to each other, each with a first oxide film formed thereon; forming a second oxide film on said semiconductor substrate to cover sidewalls of said first and second interconnection patterns; forming a silicon nitride film as an etching stopper to cover said first and second interconnection patterns with said first and second oxide films interposed therebetween; forming an interlayer insulating film on said semiconductor substrate to cover said silicon nitride film; etching, using a resist pattern, a portion of said interlayer insulating film located between said first interconnection pattern and said second interconnection pattern until a surface of said silicon nitride film is exposed, to form a contact hole; removing said resist pattern; etching said silicon nitride film at a bottom of said contact hole in a self-aligned manner to expose a surface of said second oxide film; and etching said second oxide film at the bottom of said contact hole in a self-aligned manner by setting etch selectivity of said first oxide film to said silicon nitride film to at most 1, to expose a surface of said semiconductor substrate.

Claim 10

A method of manufacturing a semiconductor device, comprising the steps of: forming on a semiconductor substrate a first interconnection pattern and a second interconnection pattern adjacent to each other, each with a first oxide film formed thereon; forming a second oxide film on said semiconductor substrate to cover both sidewalls of both of said first and second interconnection patterns; forming sidewall spacers made of a third oxide film on the both sidewalls of said first interconnection pattern and the both sidewalls of said second interconnection pattern; forming a silicon nitride film as an etching stopper to cover said first and second interconnection patterns with said first, second and third oxide films interposed therebetween; forming an interlayer insulating film on said semiconductor substrate to cover said silicon nitride film; etching, using a resist pattern, a portion of said interlayer insulating film located between said first interconnection pattern and said second interconnection pattern until a surface of said silicon nitride film is exposed, to form a contact hole; removing said resist pattern; and etching a bottom of said contact hole in a self-aligned manner to expose a surface of said semiconductor substrate.

Claim 11

A method of manufacturing a semiconductor device, comprising the steps of: forming on a semiconductor substrate a first interconnection pattern and a second interconnection pattern adjacent to each other, each with a first oxide film formed thereon; forming a second oxide film on said semiconductor substrate to cover both sidewalls of both of said first and second interconnection patterns; forming sidewall spacers made of a third oxide film on the both sidewalls of said first interconnection pattern and the both sidewalls of said second interconnection pattern; forming a silicon nitride film as an etching stopper to cover said first and second interconnection patterns with said first, second and third oxide films interposed therebetween; forming an interlayer insulating film on said semiconductor substrate to cover said silicon nitride film; etching, using a resist pattern, a portion of said interlayer insulating film located between said first interconnection pattern and said second interconnection pattern until a surface of said silicon nitride film is exposed, to form a contact hole; removing said resist pattern; and etching a bottom of said contact hole in a self-aligned manner to expose a surface of said semiconductor substrate.