Patent ID: 7967997

Claim:
A plasma etching method, comprising: plasma etching a silicon oxide film to be etched that is positioned under a multi-layer resist mask by using the multi-layer resist mask formed on a substrate to be processed; and plasma etching a glass based film positioned under the silicon oxide film by using the multi-layer resist mask, wherein as a processing gas, a gaseous mixture of C 4 F 6 gas and C 3 F 8 gas is used in the plasma etching of the glass based film, wherein the glass based film is a BPSG (Boron Phosphorus Silicate Glass) film, and wherein a ratio of a flow rate of the C 3 F 8 gas with respect to a flow rate of C 4 F 6 gas (flow rate of the C 3 F 8 gas/flow rate of the C 4 F 6 gas) is in a range of ⅜ to ⅝.