Electrostatic chuck usable in high density plasma
First Claim
1. A method for dechucking a wafer from an electrostatic chuck at the completion of a plasma process during which process a plasma is generated in a plasma chamber by RF source power, the wafer is held on the chuck by a DC potential, and said electrostatic chuck supplies a cooling gas to a backside of said wafer, said dechucking method comprising:
- at the completion of said plasma process and while the RF source power is still on, turning off said cooling gas;
changing said 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 power;
after turning off the RF source power, further separating said wafer from said electrostatic chuck; and
removing said wafer from said plasma chamber.
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Accused Products
Abstract
An electrostatic chuck for holding a wafer in a plasma processing chamber, the chuck including a pedestal having a top surface, an internal manifold for carrying a cooling gas, and a first plurality of holes leading from the internal manifold toward said top surface; and a dielectric layer on the top surface of the pedestal. The dielectric layer has a top side and second plurality of holes, 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 and the second hole 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.
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Citations
14 Claims
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1. A method for dechucking a wafer from an electrostatic chuck at the completion of a plasma process during which process a plasma is generated in a plasma chamber by RF source power, the wafer is held on the chuck by a DC potential, and said electrostatic chuck supplies a cooling gas to a backside of said wafer, said dechucking method comprising:
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at the completion of said plasma process and while the RF source power is still on, turning off said cooling gas; changing said 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 power; after turning off the RF source power, further separating said wafer from said electrostatic chuck; and removing said wafer from said plasma chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification