EP0601788A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Electrostatic chuck usable in high density plasma
Assignee: Applied Materials Inc
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Filing: 1993-12-01
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Granted: —
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Expires: 2013-12-01
Abstract
Abstract The disclosure relates to an electrostatic chuck (10) for holding a wafer (12) in a plasma processing chamber. The chuck includes a pedestal (14) having a top surface (46), an internal manifold for carrying a cooling gas, and a first plurality of holes (48) leading from the internal manifold toward said top surface; and a dielectric layer (44) on the top surface of the pedestal. The dielectric layer has a top side (54) and second plurality of holes (58), each of which is aligned with a different one of the holes of the first plurality of holes in the pedestal. The first and second holes form a plurality of passages extending from the internal manifold to the top side of the dielectric layer and through which the cooling gas is supplied to the backside of the wafer. Each of the first holes (48a to g) and the second hole (58) aligned therewith form a different one of the plurality of passages. The passages are concentrated in regions of the dielectric layer that are in proximity to regions of higher leakage of cooling gas when the wafer is held against the electrostatic chuck by an electrostatic force.
Inventors
- 👤 Kenneth S. Collins
- 👤 John R. Trow
- 👤 Joshua Chiu-Wing Tsui
- 👤 Craig A. Roderick
- 👤 Nicolas J. Bright
- 👤 Jeffrey Marks
- 👤 Tetsuya Ishikawa
- 👤 Jian Ding
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 05:00
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/70; H10P72/72; H10P72/722
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
165 words
An electrostatic chuck for holding and gas cooling a wafer during processing in a plasma reaction chamber, said chuck comprising: a metal pedestal having a smooth upper surface; and a layer or dielectric material formed on the upper surface of said pedestal, said dielectric layer having a network of cooling gas distribution grooves formed therein, the grooves of said network of gas distribution grooves penetrating said dielectric layer to a distance that is no greater than the thickness of the dielectric layer; said metal pedestal having one or more internal cavities for distributing a cooling gas, each of said internal cavities having an upper end that is separated from said dielectric layer by a layer of pedestal metal; there being for each of said internal cooling gas cavities, one or more perforations passing through said dielectric layer and the underlying layer of pedestal metal and connecting that internal cooling gas cavity with one or more of the grooves of said network of gas distribution grooves.
Claim 2
Dependent Claim
55 words
The electrostatic chuck or claim 1 wherein for each of said one of more internal cavities, there are a plurality of perforations passing through said dielectric layer and the underlying layer of pedestal metal and connecting that internal cooling gas cavity with one or more or the grooves of said network of gas distribution grooves.
Claim 3
Dependent Claim
45 words
The electrostatic chuck of claim 1 wherein the dielectric layer in which the network of distribution grooves is formed has a substantially uniform thickness and wherein the grooves of said network have a depth that is small relative to the thickness of the dielectric layer.
Claim 4
Dependent Claim
178 words
The electrostatic chuck of claim 1 wherein the pedestal has an underside, wherein said network of cooling gas distribution grooves is a dense network of grooves covering most of a region of the top surface of the dielectric layer that coincides with the backside of the wafer when said wafer is being held on said electrostatic chuck, wherein the pedestal and the dielectric layer have a plurality of lift pin holes passing therethrough, said plurality of lift pin holes extending from the underside of said pedestal to the upper surface of said dielectric layer and providing passages through which lift pins can pass to lift the wafer off of the pedestal, said lift pin holes located within said region, and wherein an annular area surrounds each of said plurality of lift pin holes, said top surface of said dielectric layer being smooth and free of grooves within said annular area so as to aid in forming a seal around each of said plurality of lift pin holes when said wafer is held on said electrostatic chuck during processing.
Claim 5
Dependent Claim
60 words
The electrostatic chuck of claim 1 wherein an annulus area surrounds the inside perimeter of said region, said top surface of said dielectric layer being smooth and free of grooves within said annulus area so as to aid in forming a seal around the outer perimeter of said wafer when said wafer is held on said electrostatic chuck during processing.
Claim 6
Dependent Claim
171 words
An electrostatic chuck for holding and gas cooling a wafer during processing in a plasma reaction chamber, said chuck comprising: a metal pedestal having an upper surface; and a layer of dielectric material formed on the upper surface of said pedestal, said dielectric layer having a top surface for receiving a backside of said wafer when said wafer is placed on said chuck; said metal pedestal having one or more internal cavities for distributing cooling gas, each of said one or more internal cavities being separated from said dielectric layer by an associated thin layer of pedestal metal, wherein for each of said one or more internal cavities, said dielectric layer has one or more first holes passing therethrough, and the associated thin layer of pedestal metal has an equal number of second holes passing therethrough and aligned with corresponding ones of said one or more first holes, wherein said first holes have a first diameter and said second holes have a second diameter that is larger than said first diameter.
Claim 7
Dependent Claim
180 words
An electrostatic chuck for holding and gas cooling a wafer during processing in a plasma reaction chamber, said chuck comprising: a metal pedestal having an upper surface; and a layer of dielectric material formed on the upper surface of said pedestal, said dielectric layer having a top surface for receiving a backside of said wafer when said wafer is placed on said chuck; said metal pedestal having one or more one internal cavities for distributing a cooling gas, each of said one or more internal cavities having an upper end that is adjacent to said dielectric layer, there being a layer of pedestal metal separating each of said one or more cavities from said dielectric layer; wherein for each of said one or more internal cavities, said dielectric layer has a plurality of first holes passing therethrough, and the associated thin layer of pedestal metal has an equal number of second holes passing therethrough and aligned with corresponding ones of said plurality of first holes, wherein said first holes have a first diameter that is less than about 0.030 inch.
Claim 8
Dependent Claim
240 words
An electrostatic chuck for holding and gas cooling a wafer during processing in a plasma reaction chamber, said chuck comprising: a metal pedestal having an upper surface and an underside; and a layer of dielectric material formed on the upper surface of said pedestal, said dielectric layer having a top surface and a dense network of cooling gas distribution grooves formed therein, said dense network of grooves covering most of a region of the top surface of the dielectric layer that coincides with the backside of the wafer when said wafer is being held on said electrostatic chuck, said metal pedestal including an internal cooling gas distribution network connected to said network of gas distribution grooves for distributing cooling gas thereto, said pedestal and dielectric layer having a plurality of lift pin holes passing therethrough, said plurality of lift pin holes extending from the underside of said pedestal to the upper surface of said dielectric layer and providing passages through which lift pins can pass to lift the wafer off of the pedestal, said lift pin holes located within said region, and wherein an annular area surrounds each of said plurality of lift pin holes, said top surface of said dielectric layer being smooth and free of grooves within said annular areas so as to aid in forming a seal around each of said plurality of lift pin holes when said wafer is held on said electrostatic chuck during processing.
Claim 9
Dependent Claim
198 words
An electrostatic chuck for holdinq a wafer in a plasma processing chamber, said chuck comprising: a pedestal having a top surface, an internal manifold for carrying a cooling gas, and a first plurality of holes leading from said internal manifold toward said top surface; and a dielectric layer on the top surface of said pedestal, said dielectric layer having a top side and second plurality of holes, each of which is aligned with a different one of the holes of said first plurality of holes in said pedestal, said first and second holes forming a plurality of passages extending from said internal manifold to the top side of said dielectric layer and through which said cooling gas is supplied to an interface formed by a backside of said wafer and the top side of said dielectric layer when said wafer is resting thereon, each of said first holes and the second hole aligned therewith forming a different one of said plurality of passages, said passages being concentrated in regions of said dielectric layer that are in proximity to regions of higher leakage of cooling gas when said wafer is held against said electrostatic chuck by an electrostatic force.
Claim 10
Dependent Claim
73 words
The electrostatic chuck of claim 9 wherein said pedestal includes a plurality of lift pins holes for allowing lift pins to pass therethrough to raise said wafer above said electrostatic chuck and wherein at least some of said plurality of passages are distributed throughout a plurality of annular regions, each annular region of said plurality of annular regions being near and centered about a different one of said plurality of lift pin holes.
Claim 11
Dependent Claim
47 words
The electrostatic chuck of claim 9 wherein said dielectric layer includes a network of grooves formed therein, wherein said network of grooves includes a plurality of annular grooves each one of which lies along the circle surrounding a different one of said plurality of lift pin holes.
Claim 12
Independent Claim
130 words
A method for dechucking a wafer from a electrostatic chuck following a plasma process during which a plasma is generated in a plasma chamber by RF source power, said electrostatic chuck supplying a cooling gas to a backside of said wafer during said plasma process, said method comprising: at the completion of said plasma process and while the RF source power is still on, turning off said cooling gas; changing a DC potential of said electrostatic chuck; slightly separating said wafer from said electrostatic chuck while said RF source plasma is still present; after slightly separating said wafer from said electrostatic chuck, turning off the RF source; after turning off the RF source power, separating said wafer further from said electrostatic chuck; and removing said wafer from said plasma chamber.
Claim 13
Dependent Claim
58 words
The dechucking method of claim 12 wherein said electrostatic chuck is biased by a DC chucking voltage during plasma processing and wherein the step of changing said DC potential of said electrostatic chuck involves reducing said DC potential of said electrostatic chuck to a DC dechucking voltage that is lower than the magnitude of the DC chucking voltage.
Claim 14
Independent Claim
170 words
A method of forming passages in an electrostatic chuck including a pedestal having a top surface covered by a dielectric layer, said dielectric layer having a top side for receiving a backside of a wafer, said chuck also including an internal manifold for carrying a cooling gas, said passageways extending from said internal manifold to the top side of said dielectric layer and for transferring the cooling gas from said internal manifold to the backside of said wafer when said wafer is resting on said dielectric layer, said method comprising: drilling a first plurality of holes into said pedestal extending from the top surface of said pedestal into said manifold; forming a dielectric layer on the surface of said pedestal, said dielectric layer being sufficiently thick to bridge over the holes of said first plurality of holes; and drilling a second plurality of holes in said dielectric layer, each hole of said second plurality of holes aligned with a different one of the holes of said first plurality of holes.
Claim 15
Dependent Claim
42 words
The method of claim 14 wherein the holes of said first plurality of holes have a first diameter and the holes of said second plurality of holes have a second diameter and wherein said first diameter is greater than said second diameter.
Claim 16
Dependent Claim
55 words
The method of claim 15 wherein said first diameter is sufficiently larger than said second diameter so that for any given one of the passages of said plurality of passages no line of sight path exists from above said dielectric layer to the portion of said pedestal that defines the first hole of that passage.
Claim 17
Dependent Claim
101 words
A computer-implemented method for preparing an electrostatic chuck within a plasma chamber to receive a next wafer for plasma processing after a previous wafer has completed plasma processing, said method comprising: removing said previous wafer from said electrostatic chuck in said plasma chamber; introducing a non-process gas into said plasma chamber without any wafer present on said electrostatic chuck in said plasma chamber; striking a plasma in said plasma chamber; running said plasma for a preselected period of time; terminating said plasma at the end of said preselected period; and placing said next wafer on said electrostatic chuck for plasma processing.
Claim 18
Dependent Claim
236 words
An electrostatic chuck for holding a wafer in a plasma processing chamber, said chuck comprising: a pedestal having a top surface, an internal manifold for carrying a cooling gas, and a first plurality of holes from said internal manifold toward said top surface; and a dielectric layer on the top surface of said pedestal, said dielectric layer having a top side and second plurality of holes, each of which is aligned with a different one of the holes of said first plurality of holes in said pedestal, said first and second holes forming a plurality of passages extending from said internal manifold to the top side of said dielectric layer and through which said cooling gas is supplied to an interface formed by the backside of said wafer and the top side of said dielectric layer when said wafer is resting thereon, each of said first holes and the second hole aligned therewith forming a different one of said plurality of passages, wherein said pedestal includes a groove formed in its top surface and further comprises an insert in said groove, said insert having a channel formed therein on a side of said insert that is opposite to the top surface of said pedestal, said channel and said groove forming a cavity that is part of said internal manifold and wherein at least some of said plurality of passages passing through said insert into said channel.
References Cited (Backward Citations)
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