US3767490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for etching organic coating layers
Assignee: International Business Machines Corp
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Filing: 1971-06-29
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Granted: 1973-10-23
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Expires: 1991-06-29
Abstract
Abstract Polyimide and other relatively inert organic insulating layers may be selectively etched by applying a masking layer to the polyimide in a desired pattern, then contacting the unmasked portions of the polyimide with ozone at an elevated temperature. When the polyimide overlies aluminum films, such as in the passivation of integrated circuits, the ozone etches the polyimide down to the aluminum film, but does not attack the aluminum. If a photoresist is utilized as the masking layer, the ozone removes the photoresist at the same time it etches the unmasked portions of the polyimide.
Inventors
- 👤 G Alberts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:44
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; G; G03; G03F; G03F7/00; G03F7/26; G03F7/42; H10W; H10W20/00; H10W20/40
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
11 words
The process of claim 1 in which said substrate comprises aluninum.
Claim 2
Dependent Claim
120 words
In the fabrication of an integrated circuit, the improvement comprising: A. forming aluminum lines for electrically interconnecting portions of said circuit, B. applying a polyimide passivation layer over said aluminum lines and said circuit, C. forming a photoresist masking layer over said polyimide passivating layer except where contact to said aluminum interconnections is desired, and D. contacting unmasked portions of said polyimide passivating layer and said photoresist masking layer with ozone for a sufficient time to remove the unmasked portions of said polyimide passivating layer and said photoresist masking layer, whereby said aluminium interconnections are exposed at the unmasked areas of said polyimide passivating layer, and said polyimide passivating layer remains where it was covered by said photoresist masking layer.
Claim 3
Dependent Claim
106 words
A process for the selective removal of an organic coating material selected from the group consisting of polyimide, a phenolic resin and an acrylic resin from a metal film which is free of attack by ozone, which comprises forming a photoresist masking layer over selected areas of said organic coating material, and contacting unmasked portions of said organic coating material and said photoresist masking layer with ozone for a sufficient time to remove the unmasked portions of said organic coating material from said metal film, whereby complete removal of unmasked organic coating material and said photoresist masking layer is achieved while maintaining said metal filM intact.
Claim 4
Dependent Claim
14 words
The process of claim 4 in which said metal film is an aluminum film.
Claim 5
Dependent Claim
13 words
The process of claim 4 in which said organic coating material comprising polyimide.
References Cited (Backward Citations)
US2443373A
Cited
US3705055A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |