Patent US5384681A successfully refreshed from Google Patents.
US5384681A
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US
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Electrostatic chuck
Assignee: Toto Ltd
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Filing: 1993-03-01
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Granted: 1995-01-24
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Expires: 2013-03-01
Abstract
Abstract An electrostatic chuck having an insulating layer comprising solid-solution grains comprised of alumina and a transition metal oxide having the structure of a corundum, and a glass component present in grain boundaries of the solid-solution grains. The transition metal oxide is a transition metal oxide capable of forming a solid solution with alumina, and preferably includes chromia (Cr2O3), whose crystal structure is similar to alumina, having the structure of a corundum. The electrostatic chuck can exhibit a stable electrostatic performance without regard to operating temperatures.
Inventors
- 👤 Tetsuo Kitabayashi
- 👤 Toshiya Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:41
CPC Classifications
H; H02; H02N; H02N13/00; B; B32; B32B; B32B18/00; C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/63; C04B35/632; C04B35/634; C04B35/63404; C04B35/6342; H10; H10P; H10P72/00; H10P72/70; H10P72/72; H10P72/722; C04B2235/00; C04B2235/65; C04B2235/656; C04B2235/6567; C04B2237/00; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/345; C04B2237/346; Y; Y10; Y10T; Y10T279/00; Y10T279/23
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
37 words
An electrastatic chuck comprising a substrate and formed thereon an internal electrode and an insulating layer, wherein said insulating layer comprises a solid-solution comprised of alumina and a transition metal oxide having the structure of a corundum.
Claim 2
Dependent Claim
37 words
An electrastatic chuck comprising a substrate and formed thereon an internal electrode and an insulating layer, wherein said insulating layer comprises a solid-solution comprised of alumina and a transition metal oxide having the structure of a corundum.
Claim 3
Dependent Claim
16 words
The electrostatic chuck according to claim 1, wherein said insulating layer further comprises a glass component.
Claim 4
Dependent Claim
25 words
The electrostatic chuck according to claim 2, wherein said transition metal oxide having the structure of a corundum is chromia Cr 2 O 3 .
Claim 5
Dependent Claim
22 words
The electrostatic chuck according to claim 3, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 6
Dependent Claim
22 words
The electrostatic chuck according to claim 2, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 7
Dependent Claim
28 words
The electrostatic chuck according to claim 1, wherein said insulating layer further comprises a glass component and not more than 2% by weight of another transition metal oxide.
Claim 8
Dependent Claim
18 words
The electrostatic chuck according to claim 6, wherein said another transition metal oxide is titania TiO 2 .
Claim 9
Dependent Claim
22 words
The electrostatic chuck according to claim 7, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 10
Dependent Claim
22 words
The electrostatic chuck according to claim 6, wherein said another transition metal oxide is present in grain boundaries of the solid solution.
Claim 11
Dependent Claim
22 words
The electrostatic chuck according to claim 9, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 12
Dependent Claim
25 words
The electrostatic chuck according to claim 6, wherein said transition metal oxide having the structure of a corundum is chromia Cr 2 O 3 .
Claim 13
Dependent Claim
22 words
The electrostatic chuck according to claim 11, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 14
Dependent Claim
22 words
The electrostatic chuck according to claim 3, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 15
Dependent Claim
25 words
The electrostatic chuck according to claim 1, wherein said transition metal oxide having the structure of a corundum is chromia Cr 2 O 3 .
Claim 16
Dependent Claim
22 words
The electrostatic chuck according to claim 14, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 17
Dependent Claim
22 words
The electrostatic chuck according to claim 1, wherein said insulating layer has a volume resistivity of not higher than 10 11 Ω·m.
Claim 18
Dependent Claim
49 words
An electrostatic chuck, comprising: a substrate; an insulating layer; and an internal electrode disposed between said substrate and said insulating layer; said insulating layer exhibits a stable volume resistivity over a temperature range of -50° C.-200° C. and at an electrical field intensity of at least 10 5 V/m.
Claim 19
Dependent Claim
49 words
An electrostatic chuck, comprising: a substrate; an insulating layer; and an internal electrode disposed between said substrate and said insulating layer; said insulating layer exhibits a stable volume resistivity over a temperature range of -50° C.-200° C. and at an electrical field intensity of at least 10 5 V/m.
Claim 20
Dependent Claim
28 words
An electrostatic chuck according to claim 17, wherein said insulating layer comprises a solid-solution comprised of alumina and a transition metal oxide having the structure of a corundum.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-23 | 1998-07-25 | 1999-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-23 | 2002-07-25 | 2003-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-23 | 2006-07-25 | 2007-01-24 | $7700.00 | Window Closed / Lapsed |