PULSE PLASMA APPARATUS AND METHOD FOR OPERATING THE SAME

摘要

In order to improve efficiency of a process of etching a semiconductor wafer using a pulse plasma by minimizing reflection power reflected from a process chamber, a pulse plasma apparatus according to the present invention applies pulse plasma power having a plurality of non-zero levels and matches an impedance by combining an impedance matching capacitance based on the plasma power having the plurality of levels according to a ratio of a duty cycle of the plasma having the plurality of levels. The pulse plasma apparatus comprises: a process chamber which includes an upper electrode and a lower electrode; a source RF generator which applies first-level RF pulse power having a first duty cycle and second-level RF pulse power having a second duty cycle to the upper electrode; a reflection power measurer which measures reflection RF power reflected again from the process chamber to the source RF generator; a first matching network which matches a plasma impedance of the process chamber with an impedance of the source RF power; and a control unit which controls the source RF generator and the first matching network so as to minimize the reflection RF power measured by the reflection power measurer.