EP0786310A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Wafer polishing head
Assignee: Lam Research Corp
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Filing: 1997-01-08
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Granted: —
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Expires: 2017-01-08
Abstract
Abstract A polishing head (10) for polishing a semiconductor wafer includes a housing (14), a wafer carrier (20) movably mounted to the housing (14), and a wafer retainer (22) movably mounted to the housing (14). The wafer carrier (20) forms a wafer supporting surface, and the wafer retainer (22) is shaped to retain a wafer in place on the wafer-supporting surface. A first fluid actuator (24,28) is coupled to the wafer carrier (20) to bias the wafer carrier (20) in a selected direction with respect to the housing (14), and a second fluid actuator (36,42) is coupled to the wafer retainer (22) to bias the wafer retainer (22) in a second selected direction with respect to the housing (14). First and second fluid conduits (30,44) are coupled to the first and second actuators, respectively, such that fluid pressures in the first and second actuators are separately and independently adjustable with respect to one another. Biasing forces on the retainer (22) can thereby be dynamically adjusted with respect to biasing forces on the carrier (20) during the polishing operation.
Inventors
- 👤 Konstantin Volodarsky
- 👤 David Edwin Weldon
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 20:45
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/27; B24B37/30
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
82 words
A polishing head for polishing a semiconductor wafer, said polishing head comprising: a housing; a wafer carrier mounted to the housing, said wafer carrier comprising a wafer-supporting surface; a wafer retainer mounted to the housing, said wafer retainer shaped to retain a wafer in place on the wafer-supporting surface; at least one of the wafer carrier and the wafer retainer movably mounted to the housing; means for creating a dynamically adjustable differential biasing force between the wafer carrier and the wafer retainer.
Claim 2
Dependent Claim
116 words
A polishing head for polishing a semiconductor wafer, said polishing head comprising: a housing; a wafer carrier mounted to the housing, said wafer carrier comprising a wafer-supporting surface; a wafer retainer mounted to the housing, said wafer retainer shaped to retain a wafer in place on the wafer-supporting surface; at least one of the wafer carrier and the wafer retainer movably mounted to the housing; a fluid actuator coupled to said at least one of the wafer carrier and the wafer retainer to selectively apply a biasing force only to said at least one of the wafer carrier and the wafer retainer, thereby dynamically adjusting relative biasing forces on the wafer carrier and the wafer retainer.
Claim 3
Dependent Claim
131 words
A polishing head for polishing a semiconductor wafer, said polishing head comprising: a housing; a wafer carrier movably mounted to the housing, said wafer carrier comprising a wafer-supporting surface; a wafer retainer movably mounted to the housing, said wafer retainer shaped to retain a wafer in place on the wafer-supporting surface; a first fluid actuator coupled to the wafer carrier to bias the wafer carrier in a first selected direction with respect to the housing; a second fluid actuator coupled to the wafer retainer to bias the wafer retainer in a second selected direction with respect to the housing; first and second fluid conduits coupled to the first and second actuators, respectively, such that fluid pressure in the first actuator is adjustable with respect to fluid pressure in the second actuator.
Claim 4
Dependent Claim
27 words
A polishing head as claimed in claim 3 further comprising a spindle secured to the housing, wherein the first and second fluid conduits extend into the spindle.
Claim 5
Dependent Claim
31 words
A polishing head as claimed in claim 4 further comprising first and second valves coupled to the first and second fluid conduits, respectively, said first and second valves being independently controllable.
Claim 6
Dependent Claim
35 words
A polishing head as claimed in claim 3 wherein the wafer carrier is mounted to the housing by a first diaphragm, and wherein the wafer retainer is mounted to the housing by a second diaphragm.
Claim 7
Dependent Claim
54 words
A polishing head as claimed in claim 6 wherein the first and second fluid actuators comprise respective first and second fluid chambers coupled to the first and second fluid conduits, respectively, said first fluid chamber bounded in part by the first diaphragm, and said second fluid chamber bounded in part by the second diaphragm.
Claim 8
Dependent Claim
27 words
A polishing head as claimed in claim 7 wherein the first fluid chamber is circular in shape, and wherein the second fluid chamber is annular in shape.
Claim 9
Dependent Claim
16 words
A polishing head as claimed in claim 8 wherein the wafer retainer is annular in shape.
Claim 10
Dependent Claim
19 words
A polishing head as claimed in claim 3 wherein the first and second directions are aligned with one another.
Claim 11
Independent Claim
80 words
A method for controlling polishing of a semiconductor wafer, said method comprising the following steps: a) mounting a semiconductor wafer on a wafer carrier of a polishing head, said wafer surrounded at least in part by a wafer retainer; b) biasing the wafer against a polishing pad with a wafer biasing force; c) biasing the wafer retainer against the polishing pad with a retainer biasing force; and d) adjusting the retainer biasing force with respect to the wafer biasing force.
Claim 12
Dependent Claim
63 words
A method as claimed in claim 11 wherein step (b) comprises the step of providing a first pressurized fluid to the polishing head, wherein step (c) comprises the step of providing a second pressurized fluid to the polishing head, and wherein step (d) comprises the step of adjusting pressure of the second pressurized fluid with respect to pressure of the first pressurized fluid.
Claim 13
Dependent Claim
17 words
A method as claimed in claim 11 wherein step (d) is accomplished during a wafer polishing operation.
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