EP0473930A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electrostatic chuck
Assignee: International Business Machines Corp
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Filing: 1991-07-26
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Granted: —
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Expires: 2011-07-26
Abstract
Abstract A split-ring electrostatic chuck (10) comprising: a substantially disc-shaped first electrode (12) having a raised central hub portion (12a) and a raised outer rim portion (12b); a second electrode (14) having a donut shape with a substantially circular wall (16) defining a central opening (18) and an outer edge (24), said hub (12a) of said first electrode engaging said central opening (18) of said second electrode (14) and said rim (12b) of said first electrode (12) surrounding said outer edge (24) of said second electrode (14); an insulator (28) electrically separating said first electrode (12) from said second electrode (14) and covering the tops (26) of said first electrode and said second electrode to form a clamping surface; a first electrical contact (46) connected to said first electrode (12); and a second electrical contact (48) connected to said second electrode (14), wherein a voltage is applied between said first electrode and said second electrode generating an attractive force for clamping a wafer to said clamping surface (26).
Inventors
- 👤 Joseph S. Logan
- 👤 Raymond R. Ruckel
- 👤 Robert E. Tompkins
- 👤 Robert P. Westerfield, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 10:55
CPC Classifications
H; H02; H02N; H02N13/00; H10; H10P; H10P72/00; H10P72/70; H10P72/72; H10P72/722; Y; Y10; Y10T; Y10T279/00; Y10T279/23; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
167 words
A split-ring electrostatic chuck (10) comprising: a substantially disc-shaped first electrode (12) having a raised central hub portion (12a) and a raised outer rim portion (12b); a second electrode (14) having a donut shape with a substantially circular wall (16) defining a central opening (18) and an outer edge (24), said hub (12a) of said first electrode engaging said central opening (18) of said second electrode (14) and said rim (12b) of said first electrode (12) surrounding said outer edge (24) of said second electrode (14); an insulator (28) electrically separating said first electrode (12) from said second electrode (14) and covering the tops (26) of said first electrode and said second electrode to form a clamping surface; a first electrical contact (46) connected to said first electrode (12); and a second electrical contact (48) connected to said second electrode (14), wherein a voltage is applied between said first electrode and said second electrode generating an attractive force for clamping a wafer to said clamping surface (26).
Claim 2
Dependent Claim
38 words
A split-ring electrostatic chuck as claimed in claim 1 wherein the depression (34) formed between said raised hub (12a) and said raised rim (12b) of said first electrode (12) has a taper of about ten degrees from normal.
Claim 3
Dependent Claim
58 words
A split-ring electrostatic chuck as claimed in claim 2 wherein said second electrode has a band (36) formed between said circular wall (16) defining said central opening (18) and said outer edge (24), said band (36) being tapered to correspond to said taper of said depression (34) of said first electrode (12), whereby said band engages said depression.
Claim 4
Dependent Claim
20 words
A split-ring electrostatic chuck as claimed in claim 1 wherein said clamping surface (26) defines two, separate, equal electrode areas.
Claim 5
Dependent Claim
17 words
A split-ring electrostatic chuck as claimed in claim 4 wherein said equal electrode areas are symmetrically distributed.
Claim 6
Dependent Claim
21 words
A split-ring electrostatic chuck as claimed in claim 1 wherein said clamping surface (26) is a single, co-planar, flat, smooth surface.
Claim 7
Dependent Claim
36 words
A split-ring electrostatic chuck as claimed in claim 1 wherein the outer boundary of the semiconductor wafer clamped by said electrostatic chuck on said clamping surface (26) extends beyond the outer boundary of said clamping surface.
Claim 8
Dependent Claim
28 words
A split-ring electrostatic chuck as claimed in claim 1 further comprising a protective ring (30) surrounding said rim (12b) of said first electrode (12) of said electrostatic chuck.
Claim 9
Dependent Claim
17 words
A split-ring electrostatic chuck as claimed in claim 8 wherein said protective ring (30) is anodized aluminum.
Claim 10
Dependent Claim
26 words
A split-ring electrostatic chuck as claimed in claim 1 wherein an epoxy bond (32) is formed between said first electrode (12) and said second electrode (14).
Claim 11
Dependent Claim
18 words
A split-ring electrostatic chuck as claimed in claim 1 wherein no electrical contact is made to said wafer.
Claim 12
Dependent Claim
37 words
A split-ring electrostatic chuck as claimed in claim 1 wherein a capacitance is generated between said first electrode (12) and said second electrode (14), said capacitance being sufficiently great to render negligible the induced rf voltage difference.
Claim 13
Dependent Claim
50 words
A split-ring electrostatic chuck as claimed in claim 1 wherein said electrostatic chuck has a network of gas distribution grooves (38) through said first electrode (12) and said second electrode (14) and a vertically disposed gas supply tube (40) through said first electrode and said second electrode connecting said grooves.
Claim 14
Dependent Claim
47 words
A split-ring electrostatic chuck as claimed in claim 13 wherein a cooling gas is passed through said gas supply tube (40) into said network of gas distribution grooves (38) to control the temperature of the semiconductor wafer clamped by said electrostatic chuck on said clamping surface (26).
Claim 15
Dependent Claim
25 words
A split-ring electrostatic chuck as claimed in claim 1 wherein said first electrode (12) has a series of cooling channels (42) for carrying a fluid.
Claim 16
Dependent Claim
27 words
A split-ring electrostatic chuck as claimed in claim 1 wherein said insulator (28) has a thickness of between approximately 0.025 and 0.08 mm (0.001 and 0.003 inches).
Claim 17
Dependent Claim
29 words
A split-ring electrostatic chuck as claimed in claim 16 wherein said insulator (28) has a breakdown voltage strength of at least 20 Volts per µm (500 volts per mil).
Claim 18
Dependent Claim
16 words
A split-ring electrostatic chuck as claimed in claim 16 wherein said insulator (28) is anodized aluminum.
References Cited (Backward Citations)
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