US5560780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective coating for dielectric material on wafer support used in integrated circuit processing apparatus and method of forming same
Assignee: Applied Materials Inc
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Filing: 1995-04-12
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Granted: 1996-10-01
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Expires: 2015-04-12
Abstract
Abstract Improvements in a wafer support apparatus used for electrostatic clamping of a wafer to the wafer support, and a method of making same, are disclosed wherein a dielectric material, formed on the surface of a wafer support facing the wafer to facilitate the electrostatic clamping, has a protective coating formed over the dielectric material to provide protection to the dielectric material against chemical attack from chemicals used during the processing of the semiconductor wafer. In a preferred embodiment, the protective coating comprises an aluminum compound, such as an oxide of aluminum or aluminum nitride, having a thickness ranging from about 1 micron to about 30 microns, but not exceeding about 50% of the thickness of the dielectric material so as to not interfere with the electrostatic charge used for clamping the wafer to the wafer support.
Inventors
- 👤 Robert Wu
- 👤 Jian Ding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:57
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/70; H10P72/72
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
74 words
In a semiconductor wafer processing apparatus wherein an aluminum wafer support has a polymeric dielectric material formed thereon to permit electrostatic clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of an inorganic aluminum compound of uniform thickness formed over at least portions of said polymeric dielectric material to protect said polymeric dielectric material from attack by chemicals used in processing said semiconductor wafer.
Claim 2
Dependent Claim
74 words
In a semiconductor wafer processing apparatus wherein an aluminum wafer support has a polymeric dielectric material formed thereon to permit electrostatic clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of an inorganic aluminum compound of uniform thickness formed over at least portions of said polymeric dielectric material to protect said polymeric dielectric material from attack by chemicals used in processing said semiconductor wafer.
Claim 3
Dependent Claim
27 words
The apparatus of claim 1 wherein said protective coating has a maximum thickness which does not exceed about 50% of the thickness of said polymeric dielectric material.
Claim 4
Dependent Claim
19 words
The apparatus of claim 2 wherein said protective coating has a maximum coating thickness not exceeding about 30 microns.
Claim 5
Dependent Claim
33 words
The apparatus of claim 3 wherein said protective coating is uniform in thickness over said polymeric dielectric material to provide uniformity in the strength of said electrostatic charges exerted on said semiconductor wafer.
Claim 6
Dependent Claim
54 words
The apparatus of claim 3 wherein the thermal coefficient of expansion of said protective coating: a) does not vary from the thermal coefficient of expansion of said wafer support by more than about 5%; and b) does not vary from the thermal coefficient of expansion of said dielectric material by more than about 5%.
Claim 7
Dependent Claim
20 words
The apparatus of claim 3 wherein said protective coating has a minimum coating thickness of at least about 1 micron.
Claim 8
Dependent Claim
20 words
The apparatus of claim 3 wherein said protective coating has a minimum coating thickness of at least about 3 microns.
Claim 9
Dependent Claim
30 words
The apparatus of claim 3 wherein said protective coating is capable of protecting said dielectric material against penetration of said protective coating by particles during processing of said semiconductor wafer.
Claim 10
Dependent Claim
57 words
The apparatus of claim 3 wherein said protective coating has a resistivity ranging from about 10 13 cm. to about 10 20 Ω cm. to permit holding of said electrostatic charges thereon during said electrostatic clamping of said wafer and release of said semiconductor electrostatic charges when said wafer is to be removed from said wafer support.
Claim 11
Dependent Claim
28 words
The apparatus of claim 3 wherein said protective coating of said inorganic aluminum compound is selected from the group consisting of an oxide of aluminum and aluminum nitride.
Claim 12
Independent Claim
14 words
The apparatus of claims 10 wherein said polymeric dielectric material comprises a polyimide material.
Claim 13
Dependent Claim
19 words
The apparatus of claim 2 wherein said protective coating has a maximum coating thickness not exceeding about 10 microns.
Claim 14
Dependent Claim
109 words
In a semiconductor wafer processing apparatus wherein a wafer support, comprising aluminum or an aluminum alloy, has a polymeric dielectric material formed thereon to permit clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of uniform thickness formed over at least portions of said dielectric material, said protective coating of uniform thickness comprising an inorganic aluminum compound having a minimum coating thickness of at least about 1 micron and a maximum coating thickness of about 30 microns formed over said polymeric dielectric material to protect said polymeric dielectric material from attack by chemicals used in processing said semiconductor wafer.
Claim 15
Dependent Claim
109 words
In a semiconductor wafer processing apparatus wherein a wafer support, comprising aluminum or an aluminum alloy, has a polymeric dielectric material formed thereon to permit clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of uniform thickness formed over at least portions of said dielectric material, said protective coating of uniform thickness comprising an inorganic aluminum compound having a minimum coating thickness of at least about 1 micron and a maximum coating thickness of about 30 microns formed over said polymeric dielectric material to protect said polymeric dielectric material from attack by chemicals used in processing said semiconductor wafer.
Claim 16
Dependent Claim
28 words
The apparatus of claim 13 wherein said protective coating has a maximum coating thickness which does not exceed about 50% of the thickness of said polymeric dielectric material.
Claim 17
Dependent Claim
32 words
The apparatus of claim 13 wherein said protective coating is uniform in thickness over said dielectric material to provide uniformity in the strength of said electrostatic charges exerted on said semiconductor wafer.
Claim 18
Dependent Claim
53 words
The apparatus of claim 13 wherein the thermal coefficient of expansion of said protective coating: does not vary from the thermal coefficient of expansion of said wafer support by more than about 5%; and b) does not vary from the thermal coefficient of expansion of said dielectric material by more than about 5%.
Claim 19
Dependent Claim
20 words
The apparatus of claim 13 wherein said protective coating has a minimum coating thickness of at least about 3 microns.
Claim 20
Dependent Claim
18 words
The apparatus of claim 13 wherein said protective coating has a maximum coating thickness of about 10 microns.
Claim 21
Dependent Claim
58 words
The apparatus of claim 13 wherein said protective coating has a resistivity ranging from about 10 13 Ω cm. to about 10 20 Ω cm. to permit holding of said electrostatic charge thereon during the electrostatic clamping of said semiconductor wafer and release of said electrostatic charge when said wafer is to be removed from said wafer support.
Claim 22
Dependent Claim
23 words
The apparatus of claim 13 wherein said aluminum compound is selected from the group consisting of an oxide of aluminum and aluminum nitride.
Claim 23
Dependent Claim
82 words
In a semiconductor wafer processing apparatus wherein an aluminum wafer support has a polymeric dielectric material formed thereon to permit clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of uniform thickness selected from the group consisting of aluminum oxide and aluminum nitride formed over at least portions of the surface of said polymeric dielectric material to protect said polymeric dielectric material from attack by chemicals used in processing said semiconductor wafer.
Claim 24
Dependent Claim
82 words
In a semiconductor wafer processing apparatus wherein an aluminum wafer support has a polymeric dielectric material formed thereon to permit clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of uniform thickness selected from the group consisting of aluminum oxide and aluminum nitride formed over at least portions of the surface of said polymeric dielectric material to protect said polymeric dielectric material from attack by chemicals used in processing said semiconductor wafer.
Claim 25
Dependent Claim
14 words
The apparatus of claim 21 wherein said polymeric dielectric material comprises a polyimide material.
Claim 26
Dependent Claim
22 words
The apparatus of claim 21 wherein said protective coating comprises aluminum oxide formed over the entire surface of said polymeric dielectric material.
Claim 27
Dependent Claim
84 words
In a semiconductor wafer processing apparatus wherein an aluminum wafer support has formed thereon a polyimide dielectric material with an electrode embedded therein comprising an electrostatic clamping structure to permit clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of uniform thickness of aluminum oxide formed over at least portions of the surface of said polyimide dielectric material to protect said polyimide dielectric material from attack by chemicals used in processing said semiconductor wafer.
Claim 28
Dependent Claim
84 words
In a semiconductor wafer processing apparatus wherein an aluminum wafer support has formed thereon a polyimide dielectric material with an electrode embedded therein comprising an electrostatic clamping structure to permit clamping of a semiconductor wafer to said wafer support by electrostatic charges, the improvement which comprises: a protective coating of uniform thickness of aluminum oxide formed over at least portions of the surface of said polyimide dielectric material to protect said polyimide dielectric material from attack by chemicals used in processing said semiconductor wafer.
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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) | 1999-10-01 | 2000-04-01 | 2000-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-01 | 2004-04-01 | 2004-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-01 | 2008-04-01 | 2008-10-01 | $7700.00 | Window Closed / Lapsed |