US4348577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High selectivity plasma etching method
Assignee: Mitsubishi Electric Corp
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Filing: 1980-09-03
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Granted: 1982-09-07
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Expires: 2000-09-03
Abstract
Abstract A parallel-plate type gas plasma etching apparatus for etching a workpiece having a multilayer structure having a high etch rate ratio. A pair of parallel-plate electrodes are disposed in a reactor. A workpiece to be etched is disposed upon one of the electrodes. The reactor is held at a predetermined pressure and an etching gas supplied thereto. Rf power is applied between the electrodes with the positive terminal of the rf generator being coupled to the electrode upon which the workpiece is disposed. The frequency of the rf power is 10 MHz or less.
Inventors
- 👤 Hiroyasu Toyoda
- 👤 Hiroyoshi Komiya
- 👤 Hideaki Itakura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:16
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
95 words
A method for preferentially etching a workpiece having a multilayer structure composed of layers of Si and SiO 2 , comprising the steps of: disposing a workpiece having layers of Si and SiO 2 upon a cathode plate of a pair of parallel-plate electrodes disposed in a reactor; providing etching gas to said reactor at a predetermined pressure; and applying rf power between said electrodes at a frequency of 400 kHz to 10 MHz with a high voltage terminal of said rf power generator coupled to said cathode plate upon which said workpiece is disposed.
Claim 2
Independent Claim
95 words
A method for preferentially etching a workpiece having a multilayer structure composed of layers of Si and SiO 2 , comprising the steps of: disposing a workpiece having layers of Si and SiO 2 upon a cathode plate of a pair of parallel-plate electrodes disposed in a reactor; providing etching gas to said reactor at a predetermined pressure; and applying rf power between said electrodes at a frequency of 400 kHz to 10 MHz with a high voltage terminal of said rf power generator coupled to said cathode plate upon which said workpiece is disposed.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said gas comprises CHF 3 .
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the pressure of said gas is 10 mTorr to 100 mTorr.
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) | 1985-09-06 | 1986-03-08 | 1986-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-06 | 1990-03-08 | 1990-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-06 | 1994-03-08 | 1994-09-07 | $7700.00 | Window Closed / Lapsed |