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Patent US5895223A successfully refreshed from Google Patents.
US5895223A
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Method for etching nitride
Assignee: Transpacific IP Ltd
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Filing: 1997-12-10
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Granted: 1999-04-20
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Expires: 2017-12-10
Abstract
Abstract A method for etching nitride is provided, by which the etching rate and the roughness of the etching surface can be powerfully controlled, and by which the etching depth can be in-situ monitored. The etching method comprises the steps of: (i) coating a first electrode on a nitride chip; (ii) mounting the nitride chip on a holding device; (iii)dipping the holding device, the nitride chip and the first electrode in electrolysis liquid; (iv) irradiating the nitride chip with a UV light having a wavelength shorter than 254 nm; and (v) connecting the first electrode to a second electrode dipped in the electrolysis liquid by a galvanometer to in-situ monitor the etching current, so as to in-situ control the etching depth.
Inventors
- 👤 Lung-Han Peng
- 👤 Chih-Wei Chuang
- 👤 Jin-Kuo Ho
- 👤 Chin-Yuan Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:19
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
90 words
A method for etching nitride, comprising the steps of: (i) coating a first electrode on a nitride chip; (ii) mounting the nitride chip on a holding device; (iii) dipping the holding device, the nitride chip and the first electrode in electrolysis liquid; (iv) irradiating the nitride chip with a UV light having a wavelength shorter than 254 nm; and (v) connecting the first electrode to a second electrode dipped in the electrolysis liquid by a galvanometer to in-situ monitor the etching current, so as to in-situ control the etching depth.
Claim 2
Independent Claim
90 words
A method for etching nitride, comprising the steps of: (i) coating a first electrode on a nitride chip; (ii) mounting the nitride chip on a holding device; (iii) dipping the holding device, the nitride chip and the first electrode in electrolysis liquid; (iv) irradiating the nitride chip with a UV light having a wavelength shorter than 254 nm; and (v) connecting the first electrode to a second electrode dipped in the electrolysis liquid by a galvanometer to in-situ monitor the etching current, so as to in-situ control the etching depth.
Claim 3
Dependent Claim
14 words
A method as claimed in claim 1, wherein the nitride chip is gallium nitride.
Claim 4
Dependent Claim
19 words
A method as claimed in claim 1, wherein the pH value of the electrolysis liquid is greater than 11.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1, wherein the pH value of the electrolysis liquid is less than 3.
Claim 6
Dependent Claim
17 words
A method as claimed in claim 1, wherein the UV light is irradiated by a mercury lamp.
Claim 7
Dependent Claim
17 words
A method as claimed in claim 1, wherein the UV light is irradiated by a xenon lamp.
Claim 8
Dependent Claim
21 words
A method as claimed in claim 1, wherein the UV light is a converting output of a frequency quadrupled quasi-molecular laser.
Claim 9
Dependent Claim
17 words
A method as claimed in claim 1, wherein the UV light is irradiated by a deuterium lamp.
Claim 10
Dependent Claim
15 words
A method as claimed in claim 1, wherein the first electrode is a dual-layer electrode.
Claim 11
Dependent Claim
24 words
A method as claimed in claim 1, wherein the work function of the first electrode is larger the electronic affinity of the nitride chip.
Claim 12
Dependent Claim
13 words
A method as claimed in claim 3, wherein the electrolysis liquid is KOH.
Claim 13
Dependent Claim
17 words
A method as claimed in claim 4, wherein the electrolysis liquid is H 3 PO 4 .
Claim 14
Dependent Claim
15 words
A method as claimed in claim 7, wherein the quasi-molecular laser is a YAG laser.
Claim 15
Dependent Claim
42 words
A method as claimed in claim 9, wherein the dual electrode comprises an inner electrode and an outer electrode, in which the outer electrode is made of one of Re, Pt, Ru, Rh, Pd, Au, Ir and Ni and a composition thereof.
Claim 16
Dependent Claim
42 words
A method as claimed in claim 9, wherein the dual electrode comprises an inner electrode and an outer electrode, in which the inner electrode is made of one of Ti, V, Cr, Zr, Mo, Hf, Ta and W and a composition thereof.
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) | 2002-04-19 | 2002-10-19 | 2003-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-04-19 | 2006-10-19 | 2007-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-04-19 | 2010-10-19 | 2011-04-20 | $7700.00 | Window Closed / Lapsed |