US5057462A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compensation of lithographic and etch proximity effects
Assignee: Nokia Bell Labs
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Filing: 1989-09-27
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Granted: 1991-10-15
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Expires: 2009-09-27
Abstract
Abstract In the manufacture of integrated-circuit devices, patterned features are made on a substrate by etching a deposited layer. The pattern comprises features which are closely spaced, as well as others which are more isolated. Etching is in approximate conformance with a lithographically defined resist pattern which in turn is in approximate conformance with a desired pattern. A processing parameter such as, e.g., resist layer thickness is chosen such that an etched pattern is obtained which approximates a desired pattern more closely than a lithographically defined resist pattern.
Inventors
- 👤 Juli H. Eisenberg
- 👤 Larry B. Fritzinger
- 👤 Chong-Cheng Fu
- 👤 Taeho Kook
- 👤 Thomas M. Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 08:37
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; Y; Y10; Y10S; Y10S438/00; Y10S438/941; Y10S438/942; Y10S438/948
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
193 words
In the manufacture of integrated-circuit devices or of integrated-circuit projection masks, a process comprising selectively etching a layer of a desired material on a substrate, etching being in at least approximate conformance with a desired pattern which comprises a plurality of features, at least one of said features being in an environment in which lithographic as well as etch proximity effects are nonnegligible, etching being preceded by a step of lithographically producing a first pattern in a resist layer on said desired layer, said first pattern being in first approximate conformance with said desired pattern, and etching of said desired layer being such as to produce a second pattern in second approximate conformance with said first pattern, characterized in that the actual value of a processing parameter is chosen such that a lithographic proximity effect is at least partially compensated for by an etch proximity effect, and such that said actual value is at least approximately equal to an optimal value of said processing parameter, said optimal value being defined such that compensation of said lithographic proximity effect by said etch proximity effect is locally optimal; said processing parameter being resist layer thickness.
Claim 2
Dependent Claim
193 words
In the manufacture of integrated-circuit devices or of integrated-circuit projection masks, a process comprising selectively etching a layer of a desired material on a substrate, etching being in at least approximate conformance with a desired pattern which comprises a plurality of features, at least one of said features being in an environment in which lithographic as well as etch proximity effects are nonnegligible, etching being preceded by a step of lithographically producing a first pattern in a resist layer on said desired layer, said first pattern being in first approximate conformance with said desired pattern, and etching of said desired layer being such as to produce a second pattern in second approximate conformance with said first pattern, characterized in that the actual value of a processing parameter is chosen such that a lithographic proximity effect is at least partially compensated for by an etch proximity effect, and such that said actual value is at least approximately equal to an optimal value of said processing parameter, said optimal value being defined such that compensation of said lithographic proximity effect by said etch proximity effect is locally optimal; said processing parameter being resist layer thickness.
Claim 3
Dependent Claim
43 words
The method of claim 1, proximity effects being determined on the basis of the width of features in a packed environment and the width of isolated features, as developed in said resist layer and as etched in said layer of a desired material.
Claim 4
Dependent Claim
22 words
The method of claim 1 in which, at said optimal value, said lithographic proximity effect is canceled by said etch proximity effect.
Claim 5
Dependent Claim
12 words
The method of claim 1 in which etching is by plasma etching.
Claim 6
Dependent Claim
16 words
The method of claim 1 in which producing said first pattern comprises projecting a mask pattern.
Claim 7
Dependent Claim
13 words
The method of claim 1 in which said desired material comprises conductor material.
Claim 8
Dependent Claim
12 words
The method of claim 6 in which said conductor material comprises polysilicon.
Claim 9
Dependent Claim
24 words
The method of claim 6 in which said conductor material is selected from the group consisting of aluminum, tungsten, tungsten silicide, and tantalum silicide.
Claim 10
Dependent Claim
13 words
The method of claim 1 in which said desired material comprises a dielectric.
Claim 11
Dependent Claim
15 words
The method of claim 1 in which resist layer thickness is greater than 0.75 micrometer.
Claim 12
Dependent Claim
19 words
The method of claim 10 in which resist layer thickness is in the range from 0.9 to 1.1 micrometer.
Claim 13
Dependent Claim
204 words
In the manufacture of integrated-circuit devices or of integrated-circuit projection masks, a process comprising selectively etching a layer of a desired material on a substrate, etching being in at least approximate conformance with a desired pattern which comprises a plurality of features, at least one of said features being in an environment in which lithographic as well as etch proximity effects are nonnegligible, etching being preceded by a step of lithographically producing a first pattern in a resist layer on said desired layer, said first pattern being in first approximate conformance with said desired pattern, and etching of said desired layer being such as to produce a second pattern in second approximate conformance with said first pattern, characterized in that the actual value of a processing parameter is chosen such that a lithographic proximity effect is at least partially compensated for by an etch proximity effect, and such that said actual value is at least approximately equal to an optimal value of said processing parameter, said optimal value being defined such that compensation of said lithographic proximity effect by said etch proximity effect is locally optimal, said processing parameter being chosen from the group of: resist prebake time, resist prebake temperature, and developer temperature.
Claim 14
Dependent Claim
204 words
In the manufacture of integrated-circuit devices or of integrated-circuit projection masks, a process comprising selectively etching a layer of a desired material on a substrate, etching being in at least approximate conformance with a desired pattern which comprises a plurality of features, at least one of said features being in an environment in which lithographic as well as etch proximity effects are nonnegligible, etching being preceded by a step of lithographically producing a first pattern in a resist layer on said desired layer, said first pattern being in first approximate conformance with said desired pattern, and etching of said desired layer being such as to produce a second pattern in second approximate conformance with said first pattern, characterized in that the actual value of a processing parameter is chosen such that a lithographic proximity effect is at least partially compensated for by an etch proximity effect, and such that said actual value is at least approximately equal to an optimal value of said processing parameter, said optimal value being defined such that compensation of said lithographic proximity effect by said etch proximity effect is locally optimal, said processing parameter being chosen from the group of: resist prebake time, resist prebake temperature, and developer temperature.
References Cited (Backward Citations)
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