Patent attributes
An apparatus and a method for holding a wafer are provided in this disclosure. The wafer holding apparatus includes: an electrostatic chuck which has a plurality of zones arranged in a matrix; a plurality of power supply units, each of which is adapted to apply a voltage to the plurality of zones of the electrostatic chuck independently; and a control unit which is adapted to control each of the power supply units independently to start or stop applying the voltage to a corresponding zone of the electrostatic chuck. Surface flatness is improved when the wafer is chucked on the wafer holding apparatus according to the disclosure, and the risk of particles contamination can be reduced when the wafer is flattened and gets back into warpage from flatness.
