Patent ID: 7869185
Filing Date: 2011-01-11
Classification: H01L

Abstract:
1. A method of de-chucking a wafer comprising: interrupting a chucking voltage applied to an electrostatic chuck; applying a first de-chucking voltage to the electrostatic chuck, the first de-chucking voltage having one of a different polarity from the chucking voltage and a zero value; applying a second de-chucking voltage to the electrostatic chuck, the second de-chucking voltage varying in polarity; supplying a de-chucking gas to a backside of the wafer, before the application of the first and second de-chucking voltages to the electrostatic chuck; measuring a leakage amount of the de-chucking gas leaked out between the wafer and the electrostatic chuck, after the application of the first and second de-chucking voltages to the electrostatic chuck; and de-chucking the wafer from the electrostatic chuck when the measured leakage amount of the de-chucking gas is larger than a tolerance leakage amount.