Patent US4812201A successfully refreshed from Google Patents.
US4812201A
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Method of ashing layers, and apparatus for ashing layers
Assignee: Tokyo Electron Ltd
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Filing: 1987-07-15
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Granted: 1989-03-14
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Expires: 2007-07-15
Abstract
Abstract A method and an apparatus, both for ashing unnecessary layers such as a photoresist layer, formed on a semiconductor wafer, by applying ozone to the layer, are disclosed. An ashing gas containing oxygen atom radical, or containing oxygen gas and an ashing-promoting gas, is applied to the layer, thereby ashing the layer readily and efficiently. The surface temperature of the layer is set at a prescribed value, and the ashing gas is applied uniformly onto the entire surface of the layer, or onto a part thereof, thus ashing the whole layer, or a part thereof, uniformly at a high rate, and the end-point of the ashing process is detected, thereby to enhance the efficiency of the ashing process.
Inventors
- 👤 Hiroyuki Sakai
- 👤 Kazutoshi Yoshioka
- 👤 Kimiharu Matsumura
- 👤 Keisuke Shigaki
- 👤 Yutaka Amemiya
- 👤 Shunichi Iimuro
- 👤 Haruhiko Yoshioka
- 👤 Teruhiko Onoe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:15
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287; G; G03; G03F; G03F7/00; G03F7/26; G03F7/42
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
103 words
An ashing method, comprising the steps of: preparing a gas mixture of ozone and nitrogen oxides excited by passing an electric discharge through dinitrogen oxide; generating oxygen atom radicals in said gas mixture by heating said gas mixture in a reaction region above a heated substrate, said gas mixture uniformly flowing over the surface layer of the substrate and the reaction region being the zone between the surface of the substrate and a plane 0.5-20 mm high above the substrate; and ashing a desired portion of the surface layer of said substrate by reaction of the surface layer with said oxygen atom radicals.
Claim 2
Dependent Claim
103 words
An ashing method, comprising the steps of: preparing a gas mixture of ozone and nitrogen oxides excited by passing an electric discharge through dinitrogen oxide; generating oxygen atom radicals in said gas mixture by heating said gas mixture in a reaction region above a heated substrate, said gas mixture uniformly flowing over the surface layer of the substrate and the reaction region being the zone between the surface of the substrate and a plane 0.5-20 mm high above the substrate; and ashing a desired portion of the surface layer of said substrate by reaction of the surface layer with said oxygen atom radicals.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein the surface temperature of the substrate ranges from 150° to 800° C.
Claim 4
Dependent Claim
30 words
The method of claim 1, further comprising the step of detecting the end point of the ashing reaction by measuring the concentration of the gas generated by the ashing reaction.
Claim 5
Dependent Claim
105 words
An ashing method, comprising the steps of: preparing a gas mixture of ozone and nitrogen oxides excited by passing an electric discharge through dinitrogen oxide; heating said gas mixture containing ozone and excited nitrogen oxides thereby generating a gas containing oxygen atom radicals; contacting the surface of a substrate with said gas mixture by allowing said gas containing oxygen atom radicals to flow uniformly over said substrate surface from its center to the periphery thereof in the radial direction of said substrate; and ashing a desired portion of the surface layer of said substrate by reaction of the surface layer with said oxygen atom radicals.
Claim 6
Dependent Claim
105 words
An ashing method, comprising the steps of: preparing a gas mixture of ozone and nitrogen oxides excited by passing an electric discharge through dinitrogen oxide; heating said gas mixture containing ozone and excited nitrogen oxides thereby generating a gas containing oxygen atom radicals; contacting the surface of a substrate with said gas mixture by allowing said gas containing oxygen atom radicals to flow uniformly over said substrate surface from its center to the periphery thereof in the radial direction of said substrate; and ashing a desired portion of the surface layer of said substrate by reaction of the surface layer with said oxygen atom radicals.
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) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |