US4877718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positive-working photosensitive polyimide operated by photo induced molecular weight changes
Assignee: International Business Machines Corp
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Filing: 1988-09-26
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Granted: 1989-10-31
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Expires: 2008-09-26
Abstract
Abstract An insoluble photosensitive polyimide having the formula ##STR1## can be exposed by a pattern of light to render the exposed areas soluble. The exposed areas can then be dissolved using a solvent to leave the pattern which can be used directly as an insulator layer in a semiconductor device. A process for preparing the photosensitive soluble polyimide utilizes maleic anhydride which is irradiated by ultraviolet light to form a cyclobutane unit which is reacted with oxydianiline to form polymic acid. The polymic acid is cured using heat into the photosensitive soluble polyimide.
Inventors
- 👤 James A. Moore
- 👤 Andrew N. Dasheff
- 👤 Frank B. Kaufman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:28
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/039; Y; Y10; Y10S; Y10S430/00; Y10S430/1053; Y10S430/1055; Y10S430/106; Y10S430/107
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
61 words
A method of forming a patterned layer for a semiconductor structure comprising: forming a layer of insoluble polyimide having the formula: ##STR5## irradiating the layer with a pattern of ultraviolet light to produce exposed and unexposed areas in the layer, the exposed areas becoming soluble; and dissolving the exposed areas from the layer using a solvent to form the patterned layer.
Claim 2
Independent Claim
61 words
A method of forming a patterned layer for a semiconductor structure comprising: forming a layer of insoluble polyimide having the formula: ##STR5## irradiating the layer with a pattern of ultraviolet light to produce exposed and unexposed areas in the layer, the exposed areas becoming soluble; and dissolving the exposed areas from the layer using a solvent to form the patterned layer.
Claim 3
Dependent Claim
14 words
A method according to claim 1 wherein the solvent is a polar aprotic solvent.
Claim 4
Dependent Claim
35 words
A method according to claim 1 including irradiating the layer with ultraviolet light having a wavelength from about 230 to 254 nm and an incident dosage of from about 10 to 1000 mJ/cm 2 .
Claim 5
Dependent Claim
42 words
A method according to claim 1 wherein the insoluble polyimide is formed by irradiating maleic anhydride to form cyclobutane tetracarboxylic dianhydride, reacting the cyclobutane tetracarboxylic dianhydride with oxydianiline to form polyamic acid and curing the polyamic acid to form the insoluble polyimide.
Claim 6
Dependent Claim
18 words
A method according to claim 4 including curing the polyamic acid into polyimide by heating the polyamic acid.
Claim 7
Dependent Claim
30 words
A method according to claim 5 including reacting the cyclobutane tetracarboxylic dianhydride with the oxydianiline in the presence of a solvent chosen from a group consisting of dimethylformamide and dimethylacetamide.
References Cited (Backward Citations)
US4112139A
Cited
US4568632A
Cited
US4579809A
Cited
US4414059A
Cited
EP0130481A1
Cited
US4508749A
Cited
US4612275A
Cited
US4655874A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |