EP0142639A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for forming narrow images on semiconductor substrates
Assignee: International Business Machines Corp
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Filing: 1984-08-23
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Granted: —
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Expires: 2004-08-23
Abstract
Abstract A method for providing very narrow resolvable line widths on a semiconductor substrate surface involves initial overexposure of a positive working photo-resist (11) through a mask (14) so as to not only expose the portions (119) of the photoresist corresponding to the transparent areas (16) of the mask but to also expose the outer periphery of the photoresist areas (116) corresponding to the opaque areas (12) of the mask. Through subsequent processing, the areas of the substrate surface corresponding to the originally unexposed areas of the photoresist are made available for use in semi- conductorfabrication, such as areas to be oxidized to function as narrow electrical isolation areas.
Inventors
- 👤 Cheryl Beth Field
- 👤 Russell Charles Lange
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 23:02
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/10; G; G03; G03F; G03F7/00; G03F7/004; G03F7/022; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2041; H10W10/01; H10W10/011
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
187 words
A method for forming narrow images on a semiconductor substrate, characterized in that it comprises the steps of: (1) forming an insulating layer (15) on the surface of said semiconductor substrate (10); (2) coating said insulating layer with a layer of positive-working photoresist (11) which can be modified to provide a negative image; (3) imagewise exposing said photoresist through a mask (14) having opaque regions (12) at locations corresponding to said recessed oxide isolation locations on said substrate and having transparent regions (16) corresponding to locations not corresponding to said recessed oxide isolation locations on said substrate under exposure conditions to expose the portions (119) of said photoresist coextensive with said transparent regions and the periphery of the areas of the photoresist corresponding to the opaque regions of said mask; (4) processing said photoresist layer in a manner to remove by developing the areas (116) of said photoresist which were not imagewise exposed in step (3) above; and (5) etching the regions of said insulating layer corresponding to the removed portions (116) of said photoresist (15) to thereby uncover the corresponding portions (7) of the semiconductor substrate.
Claim 2
Independent Claim
187 words
A method for forming narrow images on a semiconductor substrate, characterized in that it comprises the steps of: (1) forming an insulating layer (15) on the surface of said semiconductor substrate (10); (2) coating said insulating layer with a layer of positive-working photoresist (11) which can be modified to provide a negative image; (3) imagewise exposing said photoresist through a mask (14) having opaque regions (12) at locations corresponding to said recessed oxide isolation locations on said substrate and having transparent regions (16) corresponding to locations not corresponding to said recessed oxide isolation locations on said substrate under exposure conditions to expose the portions (119) of said photoresist coextensive with said transparent regions and the periphery of the areas of the photoresist corresponding to the opaque regions of said mask; (4) processing said photoresist layer in a manner to remove by developing the areas (116) of said photoresist which were not imagewise exposed in step (3) above; and (5) etching the regions of said insulating layer corresponding to the removed portions (116) of said photoresist (15) to thereby uncover the corresponding portions (7) of the semiconductor substrate.
Claim 3
Dependent Claim
28 words
The method of Claim 1 wherein said positive working photoresist consists essentially of a phenol-formaldehyde resin, a naphthoquinone (1,2)diazide sulfonic acid ester sensitizer and a 1-hydroxyethy1-2-alk y limidazoline.
Claim 4
Dependent Claim
72 words
The method of Claim 1 or 2 wherein step (4) of Claim 1 comprises (A) heating the imagewise exposed photoresist layer (119) for a sufficient period of time to a sufficient temperature to render the exposed areas insoluble in alkaline developer; (B) subsequently blanket exposing the photoresist layer with actinic radiation and (C) removing the portions of the photoresist layer which were not exposed during the imagewise exposure with an alkaline developer.
Claim 5
Dependent Claim
31 words
The method of Claim 1 wherein the positive-working photoresist is a photoresist modified by the addition of a basic compound so as to provide a negative photoresist image on a substrate.
Claim 6
Dependent Claim
48 words
The method of Claim 1 wherein an unmodified positive photoresist, after imagewise exposure, is treated by ammonia vapor, in the presence of heat or followed by a heating step, to render the imagewise exposed areas less soluble in alkaline developer than the originally unexposed areas of the photoresist.
Claim 7
Dependent Claim
29 words
The method of Claim 1 wherein,folloking step (5),the uncovered portions (7) of said semiconductor substrate are oxidized to provide recessed oxide isolation regions (13) on said semiconductor substrate surface.
References Cited (Backward Citations)
No citation records indexed.
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