System and method for clamping a work piece
A clamping system and a method of clamping a work piece are disclosed. The clamping system has an electrostatic clamp and a high-impedance voltmeter (“HIV”). The electro-static clamp may include a platen and a plurality of electrodes embedded in the platen. In use, at least some of the embedded electrodes provide one side of a capacitor and a work piece provides another side of the capacitor in order to hold the work piece relative to the platen when at least some of the embedded electrodes are electrically charged. The HIV is electrically connected to at least some of the embedded electrodes.
1. A clamping and monitoring system, comprising:
an electrostatic clamp having a platen and a plurality of electrodes (“embedded electrodes”) embedded in the platen such that the embedded electrodes are spaced apart from an outer surface of the platen that is closest to a workpiece position so as to create an electrode-to- platen-surface-distance of 1 mm or less, wherein the embedded electrodes are capable of providing one side of a capacitor and a work piece is capable of providing another side of the capacitor in order to hold the work piece to the platen when at least some of the embedded electrodes are electrically charged; and
a high-impedance voltmeter (the “HIV”) electrically connected to at least one of the embedded electrodes to measure an induced voltage arising from a voltage directly applied to the work piece in order to monitor a process that applies the voltage directly applied to the work piece, wherein the HIV has an impedance equal to or exceeding 10 16 Ohms.
2. The clamping and monitoring system of claim 1 , wherein at least some of the embedded electrodes are not electrically connected to the HIV.
3. The clamping and monitoring system of claim 2 , wherein the embedded electrodes that are not electrically connected to the HIV are larger than the embedded electrodes that are electrically connected to the HIV.