Method and apparatus for dechucking a workpiece from an electrostatic chuck
AssigneeApplied Materials, Inc.
InventorKarl F. Leeser
Life of this patent
Estimating the term…
Abstract
A method and apparatus that provides a dechucking voltage applied to an electrostatic chuck that facilitates removal of a workpiece or workpiece therefrom. The method incorporates residual chucking force information obtained from the preceding dechuck operation to modify and improve the dechucking algorithm for the subsequent wafer dechucking cycle. To avoid charge accumulation on the electrostatic chuck when processing a succession of workpieces, the chucking and dechucking voltages reverse polarity after each workpiece is dechucked.
Claims26
Apparatus for dechucking a wafer comprising:
- an electrostatic chuck having at least one embedded electrode;
- a controller;
- a power supply coupled to said controller and said at least one embedded electrode, said power supply for providing a dechucking signal to said electrostatic chuck;
- and,
- a memory communicating with said controller, said memory for storing and providing a residual force metric used by said controller for calculating said dechucking signal.
In a system that successively retains a plurality of workpieces, a method of dechucking each of said workpieces from an electrostatic chuck comprising the steps of:
- determining a first dechucking signal using a stored first residual attraction force metric;
- applying said dechucking signal to said electrostatic chuck;
- and,
- removing a first of said workpieces while measuring a second residual attraction force metric.
In a system that successively retains a plurality of workpieces, a method of dechucking each of said workpieces from an electrostatic chuck comprising the steps of:
- determining a first dechucking signal;
- applying said dechucking signal to said electrostatic chuck;
- removing a first of said workpieces;
- measuring an actual residual attraction force metric;
- and,
- providing said measured residual attraction force metric for using in determining a second dechucking signal.
A computer readable medium containing a software routine that, when execute by a processor coupled to a system that successively retains a plurality of workpieces upon an electrostatic chuck, cause the processor to perform the steps of:
- determining a first dechucking signal;
- applying said dechucking signal to said electrostatic chuck;
- removing a first of said workpieces;
- measuring an actual residual attraction force metric;
- and,
- providing said measured residual attraction force metric for using in determining a second dechucking signal.
An ion implant system comprising:
- a vacuum chamber;
- an ion beam generator coupled to said vacuum chamber;
- an electrostatic chuck positioned within said vacuum chamber and having at least one electrode
- a controller;
- a power supply coupled to said controller and said at least one embedded electrode, said power supply for providing a dechucking signal to said electrostatic chuck;
- and,
- a memory communicating with said controller, said memory for storing and providing a residual force metric used by said controller for calculating said dechucking signal.
Dependencies are inferred from the claim text.