Plasma processing method and plasma etching method

Abstract

A plasma etching apparatus includes a process chamber that can be set at a reduced pressure. A lower electrode on which a semiconductor wafer is placed and an upper electrode opposing the lower electrode are disposed in the process chamber. The lower and upper electrodes are connected to RF power supplies, respectively. First and second RF powers, the phases and power ratio of which are separately controlled, can be applied to the upper and lower electrodes. Parameters including the frequencies, power values, and relative phases of the first and second RF powers are selected in order to set the etching characteristics, e.g., an etching rate, the planar uniformity of the etching rate, the etching selectivity ratio and the like to predetermined values. During etching, the first and second RF powers are monitored by separate detectors, and are maintained at initial preset values through a controller.