US4342901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma etching electrode
Assignee: Axcelis Technologies Inc
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Filing: 1980-08-11
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Granted: 1982-08-03
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Expires: 2000-08-11
Abstract
Abstract A planar plasma etcher (10) wherein a plurality of projections (36, 136, 236) extend from one electrode (18), with each projection aligned with a wafer (22) placed on the second electrode (20) to provide uniform etching across the surface of each wafer. The surface of the projection facing the wafer can take several forms depending on etching conditions, including convex, concave or frusto-conical.
Inventors
- 👤 John Zajac
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:59
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32623; H01J37/32532; H01J37/32541
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
61 words
In a planar plasma etcher having a first electrode, and a second electrode spaced from the first and including means for receiving a plurality of wafers in a predetermined position or positions thereon; the improvement wherein the surface of said first electrode facing said second electrode is formed with a plurality of projections thereon and extending therefrom toward said second electrode.
Claim 2
Dependent Claim
61 words
In a planar plasma etcher having a first electrode, and a second electrode spaced from the first and including means for receiving a plurality of wafers in a predetermined position or positions thereon; the improvement wherein the surface of said first electrode facing said second electrode is formed with a plurality of projections thereon and extending therefrom toward said second electrode.
Claim 3
Dependent Claim
28 words
Apparatus as claimed in claim 1, in which each of said one or more projections is in substantial alignment with a corresponding one or more of said wafers.
Claim 4
Dependent Claim
19 words
Apparatus as claimed in claim 2, in which each of said projections is substantially circular in horizontal cross section.
Claim 5
Dependent Claim
46 words
Apparatus as claimed in claim 3, in which the surface of each of said projections facing said second electrode is formed with its center spaced a first predetermined distance from said second electrode and its circumferential edge spaced a second predetermined distance from said second electrode.
Claim 6
Dependent Claim
21 words
Apparatus as claimed in claim 4, in which the surface of each of said projections facing said second electrode is convex.
Claim 7
Dependent Claim
21 words
Apparatus as claimed in claim 4, in which the surface of each of said projections facing said second electrode is concave.
Claim 8
Dependent Claim
32 words
Apparatus as claimed in claim 4, in which each of said projections is formed as at least one frustum of a cone with its smaller diameter base disposed nearest said second electrode.
Claim 9
Dependent Claim
53 words
Apparatus as claimed in claim 7, in which each of said projections is formed as a plurality of frusta of cones stacked together with the base of smallest diameter nearest said second electrode and the larger diameter base of one frustum forming the smaller diameter base of the next frustum in the stack.
Claim 10
Dependent Claim
43 words
Apparatus as claimed in claims 3, 4, 5, 6, 7 or 8, in which said etcher is adapted to etch circular wafers, each of said projections having a major diameter at least as large as the diameter of the wafers to be etched.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-02 | 1986-02-01 | 1986-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-02 | 1990-02-01 | 1990-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-02 | 1994-02-01 | 1994-08-03 | $7700.00 | Window Closed / Lapsed |