Insitu contact descum for self-aligned contact process

Claim 1

A method of forming a self-aligned contact opening with fewer process steps comprising the steps of: a) forming an insulating layer over a semiconductor structure; b) coating, exposing, and developing a photoresist layer over said insulating layer; said photoresist layer having a photoresist opening over said insulating layer; c) baking said photoresist layer; d) Performing, insitu in a dry etcher, a three stage etch process comprising (1) a first descum step, (2) a dry etch step and (3) a second descum step; 1) said first descum step removing any trace amount of said photoresist layer which remains in said photoresist opening; 2) said dry etch step etching said insulating layer using said photoresist layer as a mask forming a first contact opening; said dry etch step forming a polymer at least on the sidewalls of said first contact opening; 3) said second descum treatment removing said polymer remaining in said first contact opening; e) isotropically etching said insulating layer through said photoresist opening forming a second contact opening; f) removing said photoresist layer; and g) depositing a conductive layer in said second contact opening.

Claim 2

A method of forming a self-aligned contact opening with fewer process steps comprising the steps of: a) forming an insulating layer over a semiconductor structure; b) coating, exposing, and developing a photoresist layer over said insulating layer; said photoresist layer having a photoresist opening over said insulating layer; c) baking said photoresist layer; d) Performing, insitu in a dry etcher, a three stage etch process comprising (1) a first descum step, (2) a dry etch step and (3) a second descum step; 1) said first descum step removing any trace amount of said photoresist layer which remains in said photoresist opening; 2) said dry etch step etching said insulating layer using said photoresist layer as a mask forming a first contact opening; said dry etch step forming a polymer at least on the sidewalls of said first contact opening; 3) said second descum treatment removing said polymer remaining in said first contact opening; e) isotropically etching said insulating layer through said photoresist opening forming a second contact opening; f) removing said photoresist layer; and g) depositing a conductive layer in said second contact opening.

Claim 14

A method of forming a self-aligned contact comprising the steps of: a) forming an insulating layer over a semiconductor structure; said insulating layer having a thickness in a range of between about 2700 and 4000 Å and composed of a material selected from the group consisting of TetraEthylOrthoSilicate (TEOS), borophosphosilicate glass and oxide; b) coating, exposing, and developing a photoresist layer over said insulating layer; said photoresist layer having a photoresist opening over said insulating layer; said photoresist opening having an open dimension in a range of between about 1 and 3 μm; c) performing an after developer Inspection of said photoresist layer of said photoresist layer; d) baking said photoresist layer at a temperature in a range of between about 110° and 130° C. for a time in a range of between about 30 and 50 minutes; e) performing an insitu a first descum step removing any trace amount of said photoresist layer remaining in said photoresist opening; and removing between about 100 to 300 Å of said photoresist layer; f) performing a dry etch step RIE etching said insulating layer using said photoresist layer as a mask forming a first self aligned contact opening and forming a polymer on the sidewalls of said first self aligned contact opening and leaving a thin insulating layer portion on the bottom of said self aligned contact opening; said thin insulating layer portion having a thickness in a range of between about 100 and 700 Å; g) performing a second descum treatment removing said polymer remaining in said first self aligned contact opening; said first descum treatment, said dry etch step and said second descum treatment performed insitu in a dry etcher; h) isotropically etching said insulating layer through said photoresist opening to enlarge said first self aligned contact opening forming a second self aligned contact opening and removing said thin insulating layer portion; the isotropic etch of said insulating layer comprises a buffered oxide etch (BOE) comprised of a 10:1 HF etch for a time between about 1 and 2 minutes; i) removing said photoresist layer using an ashing process; j) depositing a conductive layer in said second self aligned contact opening.

Claim 15

A method of forming a self-aligned contact comprising the steps of: a) forming an insulating layer over a semiconductor structure; said insulating layer having a thickness in a range of between about 2700 and 4000 Å and composed of a material selected from the group consisting of TetraEthylOrthoSilicate (TEOS), borophosphosilicate glass and oxide; b) coating, exposing, and developing a photoresist layer over said insulating layer; said photoresist layer having a photoresist opening over said insulating layer; said photoresist opening having an open dimension in a range of between about 1 and 3 μm; c) performing an after developer Inspection of said photoresist layer of said photoresist layer; d) baking said photoresist layer at a temperature in a range of between about 110° and 130° C. for a time in a range of between about 30 and 50 minutes; e) performing an insitu a first descum step removing any trace amount of said photoresist layer remaining in said photoresist opening; and removing between about 100 to 300 Å of said photoresist layer; f) performing a dry etch step RIE etching said insulating layer using said photoresist layer as a mask forming a first self aligned contact opening and forming a polymer on the sidewalls of said first self aligned contact opening and leaving a thin insulating layer portion on the bottom of said self aligned contact opening; said thin insulating layer portion having a thickness in a range of between about 100 and 700 Å; g) performing a second descum treatment removing said polymer remaining in said first self aligned contact opening; said first descum treatment, said dry etch step and said second descum treatment performed insitu in a dry etcher; h) isotropically etching said insulating layer through said photoresist opening to enlarge said first self aligned contact opening forming a second self aligned contact opening and removing said thin insulating layer portion; the isotropic etch of said insulating layer comprises a buffered oxide etch (BOE) comprised of a 10:1 HF etch for a time between about 1 and 2 minutes; i) removing said photoresist layer using an ashing process; j) depositing a conductive layer in said second self aligned contact opening.

Claim 20

The method of forming a self-aligned contact opening with fewer process steps comprising the steps of: a) forming an insulating layer over a semiconductor structure; b) coating, exposing, and developing a photoresist layer over said insulating layer; said photoresist layer having a photoresist opening over said insulating layer; c) baking said photoresist layer; d) Performing, insitu in a dry etcher, a three stage etch process comprising (1) a first descum step, (2) a dry etch step and (3) a second descum step; 1) said first descum step removing any trace amount of said photoresist layer which remains in said photoresist opening; 2) said dry etch step etching said insulating layer using said photoresist layer as a mask forming a first contact opening; said dry etch step forming a polymer at least on the sidewalls of said first contact opening; and 3) said second descum treatment removing said polymer remaining in said first contact opening.

Claim 21

The method of forming a self-aligned contact opening with fewer process steps comprising the steps of: a) forming an insulating layer over a semiconductor structure; b) coating, exposing, and developing a photoresist layer over said insulating layer; said photoresist layer having a photoresist opening over said insulating layer; c) baking said photoresist layer; d) Performing, insitu in a dry etcher, a three stage etch process comprising (1) a first descum step, (2) a dry etch step and (3) a second descum step; 1) said first descum step removing any trace amount of said photoresist layer which remains in said photoresist opening; 2) said dry etch step etching said insulating layer using said photoresist layer as a mask forming a first contact opening; said dry etch step forming a polymer at least on the sidewalls of said first contact opening; and 3) said second descum treatment removing said polymer remaining in said first contact opening.