Patent US5294292A successfully refreshed from Google Patents.
US5294292A
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Plasma ashing method
Assignee: Toshiba Corp
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Filing: 1990-08-27
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Granted: 1994-03-15
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Expires: 2010-08-27
Abstract
Abstract A plasma ashing method to prevent a generation of a resist-residue buildup is disclosed that includes a step for installation of a substrate on which a photoresist material is formed in a chamber, a step for drawing a vacuum in the chamber and keeping the chamber at a predetermined pressure, a step for filling oxygen gas in the camber and keeping the chamber at approximately 1 Torr, and a step for applying a high-frequency electric power of 0.10 [W/cm 2 ] or less to the oxygen gas. A more effective range of the high-frequency electric power per area of the internal wall of the chamber is from 0.008 to 0.10 [W/cm 2 ]. The most effective value of the high-frequency electric power is 0.055 [W/cm 2 ].
Inventors
- 👤 Eiji Yamashita
- 👤 Terumi Muguruma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:41
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/20; H10P70/27; H10P70/273; G; G03; G03F; G03F7/00; G03F7/26; G03F7/42; G03F7/427; H10P50/00; H10P50/20; H10P50/28; H10P50/286; H10P50/287
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
85 words
A plasma ashing method, comprising: a step for installation of a substrate on which a photoresist material is formed in a chamber having an internal wall, a step for drawing maintaining a vacuum in the chamber, a step for filling a plasma ashing gas in the chamber, and a step for supplying a high-frequency electric power to the plasma ashing gas in the chamber, wherein the high-frequency electric power per area of the internal wall of the chamber is 0.10 [W/cm 2 ] or less.
Claim 2
Dependent Claim
85 words
A plasma ashing method, comprising: a step for installation of a substrate on which a photoresist material is formed in a chamber having an internal wall, a step for drawing maintaining a vacuum in the chamber, a step for filling a plasma ashing gas in the chamber, and a step for supplying a high-frequency electric power to the plasma ashing gas in the chamber, wherein the high-frequency electric power per area of the internal wall of the chamber is 0.10 [W/cm 2 ] or less.
Claim 3
Dependent Claim
16 words
A plasma ashing method according to claim 1, wherein the photoresist material is a novolak resin.
Claim 4
Dependent Claim
33 words
A plasma ashing method according to claim 1, wherein oxygen gas as the plasma ashing gas is kept at 1 Torr in the step for filling the plasma ashing gas in the chamber.
Claim 5
Dependent Claim
30 words
A plasma ashing method according to clam 1, wherein the high-frequency electric power per area of the internal wall of the chamber is from 0.008 to 0.10 [W/cm 2 ].
Claim 6
Dependent Claim
30 words
A plasma ashing method according to clam 1, wherein the high-frequency electric power per area of the internal wall of the chamber is from 0.008 to 0.10 [W/cm 2 ].
Claim 7
Dependent Claim
28 words
A plasma ashing method according to claim 1, wherein the high-frequency electric power per area of the internal wall of the chamber is about 0.055 [W/cm 2 ].
Claim 8
Dependent Claim
14 words
A plasma ashing method according to claim 1, consisting essentially of the recited steps.
Claim 9
Dependent Claim
20 words
A plasma ashing method as claimed in claim 1, wherein the chamber is made of quartz with a ceramics door.
Claim 10
Dependent Claim
28 words
A plasma ashing method as claimed in claim 7, wherein the step of installing the substrate in the chamber comprises placement of the substrate in a quartz boat.
Claim 11
Dependent Claim
16 words
A plasma ashing method as claimed in claim 8, wherein the plasma ashing gas is oxygen.
Claim 12
Dependent Claim
16 words
A plasma ashing method as claimed in claim 1, wherein the plasma ashing gas is oxygen.
References Cited (Backward Citations)
US4474621A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-03-14 | 1997-09-13 | 1998-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-03-14 | 2001-09-13 | 2002-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-03-14 | 2005-09-13 | 2006-03-15 | $7700.00 | Window Closed / Lapsed |