US4853081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for removing contaminant
Assignee: International Business Machines Corp
•
Filing: 1987-10-30
•
Granted: 1989-08-01
•
Expires: 2007-10-30
Abstract
Abstract Contaminant is removed from the interior of the holes in the vicinity of preselected locations by etching in a gaseous plasma wherein the sheath voltage is controlled in order to direct ions of the plasma to contact the interior of the holes in the vicinity of the preselected locations.
Inventors
- 👤 Walter E. Mlynko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:07
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/0011; H05K3/0055; H05K2203/00; H05K2203/09; H05K2203/095; H05K2203/10; H05K2203/105; H05K3/40; H05K3/42; H05K3/429
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
114 words
A process for removing contaminant from holes located in a substrate and having an entrance, outer edges and interior walls which comprises etching said holes having contaminant present on the interior walls of the holes in a gaseous plasma to selectively remove contaminant from the interior of the holes in preselected locations within said holes whereby a sheath voltage is generated between said substrate and said plasma by controlling the value of the sheath voltage to direct ions of the plasma in a curved path to contact the interior of said holes in the vicinity of said preselected locations in order to selectively remote contaminant therefrom without overetching the outer edges of the holes.
Claim 2
Dependent Claim
114 words
A process for removing contaminant from holes located in a substrate and having an entrance, outer edges and interior walls which comprises etching said holes having contaminant present on the interior walls of the holes in a gaseous plasma to selectively remove contaminant from the interior of the holes in preselected locations within said holes whereby a sheath voltage is generated between said substrate and said plasma by controlling the value of the sheath voltage to direct ions of the plasma in a curved path to contact the interior of said holes in the vicinity of said preselected locations in order to selectively remote contaminant therefrom without overetching the outer edges of the holes.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein said preselected locations are interplanes.
Claim 4
Dependent Claim
43 words
The process of claim 1 wherein said sheath voltage is varied from a first value to a second value to cause ions of the plasma to contact first preselected locations within said holes and then to contact second preselected locations within said holes.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein the aspect ratio of said holes is at least about 3:1.
Claim 6
Dependent Claim
17 words
The process of claim 1 wherein the aspect ratio of said holes is at least about 9:1.
Claim 7
Dependent Claim
35 words
The process of claim 1 wherein the sheath voltage is controlled so that said ions of the plasma do not contact the interior of the holes in the vicinity of the entrance of the holes.
Claim 8
Dependent Claim
17 words
The process of claim 1 wherein said gaseous plasma is formed from oxygen and a fluorinated compound.
Claim 9
Dependent Claim
41 words
The process of claim 7 wherein the fluorinated compound is selected from the group of CF 4 , C 2 F 6 , CFCl 3 , CF 3 Cl, SF 6 , NF 3 , and CCl 2 F 2 .
Claim 10
Dependent Claim
13 words
The process of claim 7 wherein said fluorinated compound is CF 4 .
Claim 11
Dependent Claim
13 words
The process of claim 1 wherein said holes are located in dielectric substrate.
Claim 12
Dependent Claim
13 words
The process of claim 10 wherein said dielectric substrate is an epoxy substrate.
References Cited (Backward Citations)
US4012307A
Cited
US4162932A
Cited
US4328081A
Cited
US4425210A
Cited
US4540464A
Cited
US4496420A
Cited
US4544439A
Cited
US4615763A
Cited
US4599134A
Cited
US4667058A
Cited
US4654115A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-31 | 1993-01-30 | 1993-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-31 | 1997-01-30 | 1997-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-31 | 2001-01-30 | 2001-08-01 | $7700.00 | Window Closed / Lapsed |