Patent ID: 8070911
Filing Date: 2011-12-06
Classification: H01J

Abstract:
1. A capacitive coupling plasma processing apparatus for processing a target substrate having a certain outer contour, the apparatus comprising: a process chamber configured to have a vacuum atmosphere; a process gas supply section configured to supply a process gas into the chamber; a lower electrode disposed in the chamber and configured to support the target substrate thereon; an upper electrode disposed opposite the lower electrode in the chamber; and an RF (radio frequency) power supply connected to the lower electrode to apply an RF power having a frequency of 27 MHz to 160 MHz to the lower electrode to form an RF electric field within a plasma generation region between the lower and upper electrodes, so as to turn the process gas into plasma within the plasma generation region by the RF electric field, wherein the upper electrode includes a grounded conductive common base having a gas diffusion space formed therein to receive the process gas, a conductive inner segment, and a conductive outer segment disposed concentrically around and separated from the inner segment, an outer perimeter of the inner segment and an inner perimeter of the outer segment being set to be inside the outer contour of the target substrate and an outer perimeter of the outer segment being set to be outside the outer contour of the target substrate, the inner and outer segments being supported side by side by the common base through a planate insulating film such that the inner and outer segments face the lower electrode, with a plurality of gas delivery holes formed in the common base, the insulating film, and the inner and outer segments to derive the process gas from the gas diffusion space to the plasma generation region, and wherein the upper electrode is not connected to any RF power supply but is connected to a variable DC (direct current) power supply included in the apparatus, and the variable DC power supply is configured to variably apply a DC voltage between the inner and outer segments, which causes the inner segment to have an electric potential higher than that of the outer segment, so as to uniformize spatial electric potential distribution within the plasma generation region.