US4439270A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the controlled etching of tapered vias in borosilicate glass dielectrics
Assignee: International Business Machines Corp
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Filing: 1983-08-08
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Granted: 1984-03-27
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Expires: 2003-08-08
Abstract
Abstract A process is disclosed for etching openings in a relatively thick layer of borosilicate glass while controlling the degree of taper of the sidewalls of the opening, the taper being in excess of about 45°. The process involves (1) depositing a layer of silicon nitride that contains silicon in an amount in excess of stoichoimetric in Si 3 N 4 , (2) densifying the silicon nitride layer, (3) depositing a layer of resist, (4) exposing and developing the layer of resist to define a desired pattern of openings in the borosilicate glass layer, (5) removing the exposed silicon nitride areas, and (6) subjecting the resultant exposed borosilicate glass surface to an etchant for the glass.
Inventors
- 👤 Jimmie L. Powell
- 👤 Charles L. Standley
- 👤 John Suierveld
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:06
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/082; C; C03; C03C; C03C15/00; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/73; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/945
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
A process for etching openings in a relatively thick layer of borosilicate glass while controlling the degree of taper of the side walls of the opening, the taper being in excess of about 45°, which process comprises: depositing a layer of silicon nitride that contains silicon in an amount in excess of stoichoimetric in Si 3 N 4 , densifying the silicon nitride layer, depositing a layer of resist, exposing and developing the layer of resist to define a desired pattern of openings in the borosilicate glass layer, removing the exposed silicon nitride areas, and subjecting the resultant exposed borosilicate glass surface to an etchant for the glass.
Claim 2
Dependent Claim
108 words
A process for etching openings in a relatively thick layer of borosilicate glass while controlling the degree of taper of the side walls of the opening, the taper being in excess of about 45°, which process comprises: depositing a layer of silicon nitride that contains silicon in an amount in excess of stoichoimetric in Si 3 N 4 , densifying the silicon nitride layer, depositing a layer of resist, exposing and developing the layer of resist to define a desired pattern of openings in the borosilicate glass layer, removing the exposed silicon nitride areas, and subjecting the resultant exposed borosilicate glass surface to an etchant for the glass.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the taper is at least about 45°.
Claim 4
Dependent Claim
15 words
The process of claim 1 wherein the taper is at least about 45° to 60°.
Claim 5
Dependent Claim
11 words
The process of claim 1 wherein the taper is about 50°.
Claim 6
Dependent Claim
20 words
The process of claim 1 wherein the refractive index of the densified silicon nitride layer is 2.3 to about 2.8.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein the refractive index of the densified silicon nitride layer is about 2.5.
References Cited (Backward Citations)
US3447984A
Cited
US3483108A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |