摘要 |
A semiconductor device manufacturing method includes a plasma etching process for selectively plasma etching a silicon nitride film against a silicon oxide film formed under the silicon nitride film in a substrate to be processed. The plasma etching process uses an etching gas including a CmFn gas (m, n represent integers of 1 or greater) added to a gaseous mixture of a CHxFy gas (x, y represent integers of 1 or greater) and O2 gas, wherein the flow rate of the CmFn gas is not greater than 10% of that of the O2 gas. The etching gas may further include a rare gas.
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