Plasma processing apparatus

摘要

In a plasma etching apparatus, a first high frequency for plasma generation and a second high frequency for ion attraction are respectively applied from two high frequency supplies to a susceptor. Further, DC voltage is applied from a variable DC power supply to an upper electrode via a filter circuit. An annular DC ground part attached to an upper side surface of the susceptor is connected to a filter circuit. This filter circuit allows a specific frequency component of the intermodulation distortion generated in a plasma by a series resonant to selectively flow to a ground line.

主权项

1. A plasma processing apparatus comprising:
a vacuum-evacuable processing chamber; a first electrode for mounting thereon a substrate to be processed in the processing chamber; a second electrode facing the first electrode in parallel in the processing chamber; a processing gas supply unit for supplying a processing gas to a processing space between the first electrode and the second electrode; a first high frequency power supply for applying a first high frequency for plasma generation of the processing gas to at least one of the first electrode and the second electrode; a second high frequency power supply for applying to the first electrode a second high frequency for ion attraction from the plasma to the substrate; a DC power supply for applying a DC voltage to a specific member exposed to the plasma in the processing chamber; one or more DC ground electrodes, that are separate from a processing chamber wall, grounded in a DC manner and provided at a portion exposed to the plasma in the processing chamber, for allowing a DC current to flow through the plasma between the one or more DC ground electrodes and the specific member to which the DC voltage is applied; and one or more filter circuits, with each filter circuit of the one or more filter circuits including a series resonant circuit having a resonant frequency substantially the same as a frequency component generated in the plasma by intermodulation between the first and second high frequency, to selectively pass one or more frequency components generated by the intermodulation between the first and the second high frequency to a ground line via each of the one or more DC ground electrodes, wherein each of the one or more DC ground electrodes is electrically connected to at least one filter circuit of the one or more filter circuits, and wherein each filter circuit of the one or more filter circuits further includes a DC series circuit such that the DC current passes through the DC series circuit to the ground line, and such that each filter circuit includes both said DC series circuit and said series resonant circuit.