Patent ID: 6202590
Filing Date: 2001-03-20
Classification: H01J

Abstract:
A plasma apparatus, comprising: performed;a chuck mounted in the chamber and insulated from the chamber;a chuck plasma power source connected to the chuck;a system controller for outputting a signal for controlling the chuck plasma power source; anda capacitance compensator for keeping the total chuck capacitance between the chuck and a ground terminal at a constant value,wherein the capacitance compensator comprises:a variable capacitor portion connected between the chuck and the ground terminal and comprising at least one variable capacitor; anda variable capacitor controller for controlling the capacitance of the variable capacitor,wherein the variable capacitor controller comprises:a motive power source for changing a gap between electrodes of the variable capacitor;a capacitance meter for measuring the total chuck capacitance between the chuck and the ground terminal and outputting an electrical signal corresponding to the measured total chuck capacitance;an automatic control signal generator for outputting an electrical signal corresponding to the difference between the output signal of the capacitance meter and a reference signal that corresponds to an optimal total chuck capacitance input to the system controller; anda driver portion for driving the motive power source by amplifying the output signal of the automatic control signal generator.