Patent ID: 8169769

Claim:
A detection circuit for a power supply for an electrostatic chuck, the power supply having a signal generating circuit configured to generate an input, a power output circuit configured to produce a signal for the electrostatic chuck in response to the input signal, and a feedback circuit electrically connected to the power output circuit and configured to feed back a voltage signal responsive to a voltage on the electrostatic chuck, wherein the signal from the power output circuit is a trapezoidal waveform with approximately flat tops and minimal dead-time between phase reversals, the detection circuit electrically connected to the electrostatic chuck through the feedback circuit and comprising: an amplifying circuit receiving inputs from the power output circuit and producing an amplified buffered signal; a chucking quality circuit receiving the signal from the amplifying circuit, and configured to produce a signal indicative of a quality of a chucked substrate; and a movement detection circuit receiving the signal from the amplifying circuit, and configured to produce a signal indicative of movement of the substrate on the chuck.