US4749589A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of surface treatment
Assignee: Nortel Networks Ltd
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Filing: 1985-12-10
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Granted: 1988-06-07
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Expires: 2005-12-10
Abstract
Abstract In a pulsed plasma process for surface treatment of a substrate the containing reactor vessel (11) has an inner cross-section conforming to the substrate geometry so as to confine the intense plasma region to the substrate surface (12). Preferably this region should be within 15 to 20 mm of the surface. Advantageously the inner surface is provided by a demountable insert (13).
Inventors
- 👤 Rudolf A. H. Heinecke
- 👤 Sureshchandra M. Ojha
- 👤 Ian P. Llewellyn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:54
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32458; H01J37/02; H01J37/16; H01J37/32623
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
In a method of surface treatment of a substrate body by exposing the body surface to a pulsed radio frequency plasma discharge wherein the plasma is subjected to a pulsed power of 200 to 250 watts per square centimeter of the body surface whereby the plasma is substantially completely dissociated during each said pulse, the improvement comprising confining the plasma discharge to a region having a cross section configuration corresponding to the shape of the substrate body and adjacent the body surface, said region extending to a distance of 15 to 25 mm from the body surface.
Claim 2
Dependent Claim
97 words
In a method of surface treatment of a substrate body by exposing the body surface to a pulsed radio frequency plasma discharge wherein the plasma is subjected to a pulsed power of 200 to 250 watts per square centimeter of the body surface whereby the plasma is substantially completely dissociated during each said pulse, the improvement comprising confining the plasma discharge to a region having a cross section configuration corresponding to the shape of the substrate body and adjacent the body surface, said region extending to a distance of 15 to 25 mm from the body surface.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1 wherein the plasma discharge is maintained at a pressure of 1 to 1000 mtorr.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 1 wherein the plasma discharge is further confined by an applied magnetic field.
Claim 5
Dependent Claim
22 words
A method as claimed in claim 1 wherein the plasma discharge is confined in a shaped insert contained in a reactor vessel.
References Cited (Backward Citations)
GB785878A
Cited
GB854989A
Cited
GB1153787A
Cited
GB1544172A
Cited
GB2105729A
Cited
EP0095200A2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-07 | 1991-12-07 | 1992-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-07 | 1995-12-07 | 1996-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-07 | 1999-12-07 | 2000-06-07 | $7700.00 | Window Closed / Lapsed |