Patent ID: 9583315
Date: 2017-02-28
CPC Classifications: H01J,H01L

Claim:
1. A plasma etching apparatus for etching a substrate by plasma of a processing gas, the plasma etching apparatus comprising: a processing container; a substrate holding unit provided at a bottom portion of the processing container and configured to hold a substrate; a gas shower head including a buffer chamber provided at an upper portion of the processing container to face the substrate holding unit, the buffer chamber being concentrically divided into n regions (where n is a natural number of two or more) in a radial direction and each of the n regions being provided with a plurality of gas supply units which are equidistantly formed therein in order to supply the processing gas to a space between the gas shower head and the substrate holding unit; a high frequency power source configured to supply a high frequency power to at least one of the substrate holding unit and the gas shower head so as to generate plasma from the processing gas supplied into the space by the plurality of gas supply units; and a controller configured to control a flow rate of the processing gas supplied from the plurality of gas supply units in each of the n regions based on the following equation: Q: total flow rate of processing gas Q D N