HIGH-FREQUENCY PLASMA ETCHING DEVICE

摘要

PURPOSE:To control easily the DC voltage between a high-frequency electrode and earth electrode in a high-frequency plasma etching device to an optimum value by forming a DC bypass circuit between the two electrodes and regulating the resistance value thereof. CONSTITUTION:The water-cooled high-frequency electrode 2 is placed in a chamber 1 acting as the earth electrode and a reactive gas is supplied into the chamber through a supply port 4. While the gas is discharged through a discharge port 5, a high-frequency voltage is impressed between the two electrodes 1 and 2 from a high-frequency power source HF via a matching circuit consisting of a variable inductance Lv and variable capacitance Cv and a coupling capacitor Cc to maintain the plasma atmosphere in the chamber 1 by which a material 3 to be treated on the electrode 2 is subjected to an etching treatment. The high-frequency current is removed by a low-pass filter consisting of an inductance Lo and capacitance Co to to pass only the DC current of a bypass resistor RB. The current value and DC voltage value are respectively measured by means I, V and the RB is regulated, by which the DC voltage V is regulated as desired.