US4844767A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for etching
Assignee: Hitachi Ltd
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Filing: 1988-02-16
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Granted: 1989-07-04
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Expires: 2008-02-16
Abstract
Abstract A plasma which is formed by the contact between a microwave and a reaction gas is brought into contact with an article to be etched which is AC-biased, thereby effecting etching of an exposed region of the article. The etching is carried out in a state wherein the self-bias formed between the plasma and the article is minimized, whereby it is possible to effect etching which provides high selectivity and which enables a substantially vertical side wall to be formed.
Inventors
- 👤 Sadayuki Okudaira
- 👤 Shigeru Nishimatsi
- 👤 Keizo Suzuki
- 👤 Ken Ninomiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:11
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32009; H01J37/32192; H01J37/32431; H01J37/32697; H01J37/32706; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H01J2237/00; H01J2237/32; H01J2237/33; H01J2237/334; H01J2237/3343; H01J2237/3346
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
129 words
An etching apparatus comprising: means for forming a microwave; a vacuum chamber in which an electric discharge space is defined; means for introducing a reaction gas into said electric discharge space of said vacuum chamber; table means disposed within said vacuum chamber for mounting an article to be etched thereon; means for introducing said microwave into said electric discharge space such that a plasma is generated by contact between said reaction gas and said microwave for enabling etching of said article by said plasma; an electrically fixed electrode means, separate from said table means, for fixing a potential of said plasma at a predetermined value; and means for applying a predetermined AC bias to said article so as to control a self-bias produced between said article and said plasma.
Claim 2
Dependent Claim
129 words
An etching apparatus comprising: means for forming a microwave; a vacuum chamber in which an electric discharge space is defined; means for introducing a reaction gas into said electric discharge space of said vacuum chamber; table means disposed within said vacuum chamber for mounting an article to be etched thereon; means for introducing said microwave into said electric discharge space such that a plasma is generated by contact between said reaction gas and said microwave for enabling etching of said article by said plasma; an electrically fixed electrode means, separate from said table means, for fixing a potential of said plasma at a predetermined value; and means for applying a predetermined AC bias to said article so as to control a self-bias produced between said article and said plasma.
Claim 3
Dependent Claim
20 words
An etching apparatus according to claim 1, further comprising: means for generating a magnetic field within said electric discharge space.
Claim 4
Dependent Claim
24 words
An etching apparatus according to claim 1, wherein the effective area of said electrically fixed electrode is smaller than the area of said table.
Claim 5
Dependent Claim
37 words
An etching apparatus according to claim 1, wherein said means for applying a predetermined AC bias includes frequency control means for controlling said AC bias so as to have a frequency from 10 KHz to 10 MHz.
Claim 6
Dependent Claim
24 words
An etching apparatus according to claim 1, wherein said means for applying said predetermined AC bias includes a matching circuit connected to said table.
Claim 7
Dependent Claim
54 words
An etching apparatus according to claim 1, wherein said means for applying a predetermined AC bias includes control means for controlling said self-bias produced between said article and said plasma so as to be reduced to substantially zero such that etching selectivity of said article is increased and side-etching of said article is decreased.
Claim 8
Dependent Claim
31 words
An etching apparatus according to claim 1, wherein said means for applying a predetermined AC bias includes control means for controlling said self-bias so as to be reduced to minimum value.
Claim 9
Independent Claim
110 words
A method of etching an article in a vacuum chamber including a table means for mounting said article within said vacuum chamber, and an electrically fixed electrode separate from said table means within said vacuum chamber, comprising the steps of: forming a plasma of a reaction gas by exciting said reaction gas with a microwave within said vacuum chamber; fixing a potential of said plasma to a predetermined value using said electrically fixed electrode; exposing said article to said plasma to effect etching of predetermined regions of said article; and applying said article with an AC bias so as to control a self-bias produced between said plasma and said article.
Claim 10
Independent Claim
110 words
A method of etching an article in a vacuum chamber including a table means for mounting said article within said vacuum chamber, and an electrically fixed electrode separate from said table means within said vacuum chamber, comprising the steps of: forming a plasma of a reaction gas by exciting said reaction gas with a microwave within said vacuum chamber; fixing a potential of said plasma to a predetermined value using said electrically fixed electrode; exposing said article to said plasma to effect etching of predetermined regions of said article; and applying said article with an AC bias so as to control a self-bias produced between said plasma and said article.
Claim 11
Dependent Claim
28 words
An etching method according to claim 8, wherein said self-bias is controlled setting a matching circuit for applying said AC bias to said article in an off-matching condition.
Claim 12
Dependent Claim
43 words
An etching method according to claim 8, wherein said self-bias is controlled by applying a voltage to said electrically fixed electrode, said voltage having an absolute value substantially equal to that of said self-bias and a polarity opposite to that of said self-bias.
Claim 13
Dependent Claim
24 words
An etching method according to claim 8, wherein the AC bias applied to said article has a frequency of 10 KHz to 10 MHz.
Claim 14
Dependent Claim
45 words
A method of etching an article in a vacuum chamber according to claim 8, wherein said self-bias produced between said plasma and said article is minimized to substantially zero such that etching selectivity of said article is increased and side-etching of said article is decreased.
Claim 15
Dependent Claim
24 words
A method of etching an article according to claim 8, wherein said self-bias is controlled so as to be reduced to a minimum value.
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) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |