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US4155866A
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Method of controlling silicon wafer etching rates-utilizing a diazine catalyzed etchant
Assignee: International Business Machines Corp
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Filing: 1978-04-24
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Granted: 1979-05-22
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Expires: 1998-04-24
Abstract
Abstract A method for controlling the etch rate of a quaternary etchant comprising ethylene diamine, water, pyrocatechol and a diazine. The etching rate is catalyzed and controlled by controlling the amount of the diazine present in the etchant. A method for the controlled etching of silicon is also disclosed.
Inventors
- 👤 Melvin Berkenblit
- 👤 Dennis C. Green
- 👤 Frank B. Kaufman
- 👤 Arnold Reisman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 04:06
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/126; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/644
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
47 words
A method for etching silicon including the steps of: (a) preparing an etch solution comprising ethylenediamine, pyrocatechol, water and a predetermined amount of a diazine, (b) applying said etch solution to said silicon at a temperature and for a time sufficient to effect the desired etch pattern.
Claim 2
Independent Claim
47 words
A method for etching silicon including the steps of: (a) preparing an etch solution comprising ethylenediamine, pyrocatechol, water and a predetermined amount of a diazine, (b) applying said etch solution to said silicon at a temperature and for a time sufficient to effect the desired etch pattern.
Claim 3
Dependent Claim
30 words
A method according to claim 1 wherein said diazine is selected from the group consisting of 1,4-diazine, 1, 2-diazine, phthalazine, pyridopyrazine, phenazine, 2, 5 diamethylpyrazine, 2,6 diamethylpyrazine, tetramethylpyrazine and phenylpyrazine.
Claim 4
Dependent Claim
25 words
The method of claim 2 wherein said diazine is present in the amount of from about 2 to about 4 grams per liter of ethylendiamine.
Claim 5
Dependent Claim
56 words
The method of claim 3 wherein said etch solution contains from about 700 ml to about 800 ml of ethylenediamine, from about 200 ml to about 250 ml of water, from about 100 grams to about 150 grams of pyrocatechol and from about 2 grams to about 4 grams of a diazine per liter of ethylenediamine.
Claim 6
Dependent Claim
36 words
The method of claim 4 wherein there is present in said etch solution 750 ml of ethylenediamine, 240 ml water and 120 grams of pyracatechol, said ethylenediamine having dissolved therein 2.5 g/liter of diazine of ethylenediamine.
Claim 7
Dependent Claim
11 words
A method according to claim 2 wherein said diazine is 1,4-diazine.
Claim 8
Dependent Claim
11 words
A method according to claim 2 wherein said diazine is 1,2-diazine.
Claim 9
Dependent Claim
15 words
A quaternary etch solution comprising ethylenediamine, pyrocatechol, water and a prdetermined amount of a diazine.
Claim 10
Dependent Claim
15 words
A quaternary etch solution comprising ethylenediamine, pyrocatechol, water and a prdetermined amount of a diazine.
Claim 11
Dependent Claim
29 words
An etch solution according to claim 8 wherein said diazine is selected from the group consisting of 1,4-diazine, 1,2-diazine, phthalzine, pyridopyrazine, phenazine, 2,5 dimethylpyrazine, 2,6 diamethylpyrazine, tetramethylpyrazine, and phenylpyrazine.
Claim 12
Dependent Claim
55 words
The etch solution of claim 9 wherein there is present from about 700 ml to about 800 ml of ethylenediamine from about 100 grams to about 150 grams of pyrocatechol from about 200 ml 250 ml of water, and said diazine being dissolved in said ethyldiamine from about 2 g/liter to about 4 grams liter.
Claim 13
Dependent Claim
29 words
An etch solution to claim 9 wherein there is present 750 ml of ethylenediamine, 240 ml of water 120 grams of pyracatechol and 2.5 g/liter of diazine of ethylenediamine.
Claim 14
Dependent Claim
13 words
An etch solution according to claim 9 wherein said diazine is 1,2 diazine.
References Cited (Backward Citations)
US3936332A
Cited
US4113551A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-05-21 | 1982-11-20 | 1983-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-05-21 | 1986-11-20 | 1987-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-05-21 | 1990-11-20 | 1991-05-22 | $7700.00 | Window Closed / Lapsed |