Patent ID: 8581598
Filing Date: 2013-11-12
Classification: B23Q,H01L

Abstract:
1. A method of inspecting an electrostatic chuck, which is used in an electrostatic chuck apparatus comprising: an electrostatic chuck of bipolar type for attracting an object to be attracted by means of static electricity, comprising, in a dielectric body, a positive attracting electrode and a negative attracting electrode arranged along a surface of the dielectric body; a chuck power supply for supplying, with a ground potential portion set as a reference, a positive direct current voltage and a negative direct current voltage to the positive attracting electrode and the negative attracting electrode of the electrostatic chuck, respectively; and a positive auxiliary electrode and a negative auxiliary electrode on a back surface side of the positive attracting electrode and the negative attracting electrode in the dielectric body of the electrostatic chuck, the positive auxiliary electrode and the negative auxiliary electrode being arranged so as to face the positive attracting electrode and the negative attracting electrode, respectively, with a predetermined gap therebetween, and being connected to the ground potential portion, the method of inspecting an electrostatic chuck comprising a determination step of: measuring each of at least three of transient currents obtained when, under a state in which the object to be attracted is not mounted on the electrostatic chuck, the positive direct current voltage and the negative direct current voltage are applied to the electrostatic chuck from the chuck power supply or cease to be applied to the electrostatic chuck from the chuck power supply, the transient currents comprising: calculating a fifth transient current representing a difference between the first transient current and the second transient current or a difference between the third transient current and the fourth transient current; comparing obtained transient currents to respective reference values of transient currents obtained from a normal electrostatic chuck; and determining a capacitance abnormality in a vicinity of each of the positive attracting electrode and the negative attracting electrode of the electrostatic chuck.