US3884696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positive photoresist comprising polysulfones formed by reacting vinyl aromatic hydrocarbons with sulfur dioxide
Assignee: AT&T Inc
•
Filing: 1974-03-05
•
Granted: 1975-05-20
•
Expires: 1994-03-05
Abstract
Abstract A technique is described for the generation of a patterned relief image in a sensitive positive photoresist comprising a polysulfone formed by reacting vinyl aromatic hydrocarbons with sulfur dioxide. Pattern generation is effected by exposure of the polysulfone to ultraviolet radiation of a wavelength within the range of 1,700-4,000 A. and selective removal of the exposed portion with a suitable solvent.
Inventors
- 👤 Murrae John Stanley Bowden
- 👤 Edwin Arthur Chandross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:42
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/039; C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/54; C07F9/5407
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
69 words
THE METHOD OF FORMING A PATTERNED RESIST ON THE SURFACE OF A SUBSTRATE WHICH COMPRISES EXPOSING A PORTION OF AN ARYLATED POLYSULFONE FILM ON SAID SUBSTRATE TO ULTRAVIOLET RADIATION HAVING A WAVELENGTH WITHIN THE RANGE OF 1,700-4,000 A FOR A TIME PERIOD SUFFICIENT TO LOWER THE MOLECULAR WEIGHT OF THE POLYSULFONE, AND SELECTIVELY REMOVING THE EXPOSED PORTION FROM SAID SUBSTRATE, SAID POLYSULFONE BEING SELECTED FROM THE GROUP CONSISTING OF
Claim 2
Independent Claim
69 words
THE METHOD OF FORMING A PATTERNED RESIST ON THE SURFACE OF A SUBSTRATE WHICH COMPRISES EXPOSING A PORTION OF AN ARYLATED POLYSULFONE FILM ON SAID SUBSTRATE TO ULTRAVIOLET RADIATION HAVING A WAVELENGTH WITHIN THE RANGE OF 1,700-4,000 A FOR A TIME PERIOD SUFFICIENT TO LOWER THE MOLECULAR WEIGHT OF THE POLYSULFONE, AND SELECTIVELY REMOVING THE EXPOSED PORTION FROM SAID SUBSTRATE, SAID POLYSULFONE BEING SELECTED FROM THE GROUP CONSISTING OF
Claim 3
Dependent Claim
13 words
Method in accordance with claim 1 wherein R is a 1.8 naphthylidene radical.
Claim 4
Dependent Claim
13 words
Method in accordance with claim 1 wherein said radical is a naphthyl radical.
Claim 5
Dependent Claim
13 words
Method in accordance with claim 1 wherein said radical is a phenyl radical.
Claim 6
Independent Claim
124 words
The method of forming a patterned resist on the surface of a substrate which comprises exposing a portion of a film of a polysulfone, made up of polymer chains having recurring -CH -SO2- linkages, on said substrate to sufficient radiation to lower the molecular weight of said exposed portion and selectively removing the exposed portion of lower molecular weight from said substrate, characterized in that the carbon atoms in said linkages in the initial polysulfone are bonded by one of their valences to the ring of an aromatic radical so as to render said linkages sensitive to ultraviolet radiation and characterized further in that the radiation to which said portions are exposed is ultraviolet radiation, said polysulfone being selected from the group consisting of
Claim 7
Independent Claim
124 words
The method of forming a patterned resist on the surface of a substrate which comprises exposing a portion of a film of a polysulfone, made up of polymer chains having recurring -CH -SO2- linkages, on said substrate to sufficient radiation to lower the molecular weight of said exposed portion and selectively removing the exposed portion of lower molecular weight from said substrate, characterized in that the carbon atoms in said linkages in the initial polysulfone are bonded by one of their valences to the ring of an aromatic radical so as to render said linkages sensitive to ultraviolet radiation and characterized further in that the radiation to which said portions are exposed is ultraviolet radiation, said polysulfone being selected from the group consisting of
References Cited (Backward Citations)
US3535137A
Cited
US3585118A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |