双極型静電チャックの特性評価 Performance Evaluation of Bipolar Electrostatic Chucks
The electrostatic chuck (ESC) is being applied to the wafer stages for various kinds of semiconductor-manufacturing machines. This is because the ESC can control the wafer temperature very precisely if helium backside gas is used at the same time. The basic components of the ESC are an electrode and a dielectric layer. The wafer is attracted to the dielectric layer by the coulomb force generated from the electric charge when DC voltage is applied betwween the electrode and wafer. However, a residual clamping force remains if a charge remains after DC votage release. Preventing this residual clamping force is a key to using the ESC because it degrades wafer throughput. We have examined how this clamping force degrades the performance of a bipolar ESC with electrically independent dual electrodes. The cause of the residual clamping force was studied on the basis of an equilibrium circuit of ESC.
真空 42(9), 840-844, 1999-09-20
The Vacuum Society of Japan