US4371608A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resist system having increased light response
Assignee: IONOMET COMPANY Inc
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Filing: 1981-06-22
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Granted: 1983-02-01
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Expires: 2001-06-22
Abstract
Abstract A chalcogenide such as As 2 S 3 is coated on a substrate at a very low rate of deposition in a vacuum evaporator and is coated with a thin silver layer. The silver coated layer is exposed to illumination in a quantity insufficient to form an etchable layer by conventional techniques and the silver is increased by treatment with a silver-containing agent capable of depositing silver on the image, preferably in the presence of radiation. NaAgSO 3 is a presently preferred agent. The resulting image-bearing layer is photo-doped by exposure to band-gap radiation and the member is then etched.
Inventors
- 👤 Amitabha Das
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:15
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/0042; G03F7/0044; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/924; Y10S438/97
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
181 words
A process of microlithography for preparing an element useful in the production of semiconductor devices comprising coating a thin layer of silver on a chalcogenide surface on a semiconductor element substrate, exposing the silver-coated chalcogenide layer to activating radiation in a pattern corresponding to the desired semiconductor device pattern on the substrate in a radiation time and intensity of about 5 milliJoules per square centimeter to form a weak silver image insufficient to form a fully etchable chalcogenide, removing silver from the background areas of the chalcogenide surface, treating the chalcogenide surface with a desensitizing agent to neutralize the chalcogenide surface against the subsequent silver deposition thereon from a silver-containing agent, intensifying the silver image pattern on the chalcogenide with an intensifying agent containing depositable silver to deposit additional silver material on the silver image areas on the chalcogenide, and driving the silver image into the chalcogenide by suitable radiation to form an etch resistant cap on the chalcogenide in the image areas, whereby there is formed an etchable image on the chalcogenide surface corresponding to a desired semiconductor device pattern.
Claim 2
Dependent Claim
181 words
A process of microlithography for preparing an element useful in the production of semiconductor devices comprising coating a thin layer of silver on a chalcogenide surface on a semiconductor element substrate, exposing the silver-coated chalcogenide layer to activating radiation in a pattern corresponding to the desired semiconductor device pattern on the substrate in a radiation time and intensity of about 5 milliJoules per square centimeter to form a weak silver image insufficient to form a fully etchable chalcogenide, removing silver from the background areas of the chalcogenide surface, treating the chalcogenide surface with a desensitizing agent to neutralize the chalcogenide surface against the subsequent silver deposition thereon from a silver-containing agent, intensifying the silver image pattern on the chalcogenide with an intensifying agent containing depositable silver to deposit additional silver material on the silver image areas on the chalcogenide, and driving the silver image into the chalcogenide by suitable radiation to form an etch resistant cap on the chalcogenide in the image areas, whereby there is formed an etchable image on the chalcogenide surface corresponding to a desired semiconductor device pattern.
Claim 3
Dependent Claim
28 words
The process of claim 1, wherein the step of intensifying the silver image is carried out in the presence of radiation less than about one micron wave length.
Claim 4
Dependent Claim
13 words
The process of claim 1, wherein the intensifying agent is NaAgSO 3 .
Claim 5
Dependent Claim
15 words
The process of claim 1, wherein the intensifying agent is NaAg(NO 2 ) 2 .
Claim 6
Dependent Claim
23 words
The process of claim 1, wherein the thin silver layer on the chalcogenide is formed thereon by chemical reduction of a silver salt.
Claim 7
Dependent Claim
22 words
The process of claim 1, wherein the background, non-image areas are neutralized by immersing the surface in a solution of potassium dichromate.
Claim 8
Dependent Claim
14 words
The process of claim 1, wherein the chalcogenide is As 2 S 3 .
Claim 9
Dependent Claim
143 words
In a process of preparing a photo-doped chalcogenide layer on a substrate for the manufacture of semiconductor devices, the steps comprising coating a thin layer of silver on a chalcogenide surface on a semiconductor wafer, exposing the silver layer to activating radiation in a pattern corresponding to a desired semiconductor device pattern to form a weak silver image insufficient to form a fully etchable chalcogenide, desensitizing the background, non-image areas to neutralize the chalcogenide surface against subsequent deposition thereon from a silver-containing agent, intensifying the silver image in the exposed image areas by treating the layer with an intensifying agent containing depositable silver to deposit additional silver material on the silver-containing image areas to form an image of increased silver, and driving the silver image into the chalcogenide by suitable radiation to form an etch-resistant cap on the chalcogenide in the image areas.
Claim 10
Dependent Claim
143 words
In a process of preparing a photo-doped chalcogenide layer on a substrate for the manufacture of semiconductor devices, the steps comprising coating a thin layer of silver on a chalcogenide surface on a semiconductor wafer, exposing the silver layer to activating radiation in a pattern corresponding to a desired semiconductor device pattern to form a weak silver image insufficient to form a fully etchable chalcogenide, desensitizing the background, non-image areas to neutralize the chalcogenide surface against subsequent deposition thereon from a silver-containing agent, intensifying the silver image in the exposed image areas by treating the layer with an intensifying agent containing depositable silver to deposit additional silver material on the silver-containing image areas to form an image of increased silver, and driving the silver image into the chalcogenide by suitable radiation to form an etch-resistant cap on the chalcogenide in the image areas.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-31 | 1986-08-02 | 1987-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-31 | 1990-08-02 | 1991-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-31 | 1994-08-02 | 1995-02-01 | $7700.00 | Window Closed / Lapsed |