摘要 |
The present invention provides a dry etching method capable of readily providing rounded top edge portions, called top rounds, at trenches and vias formed by removal of a dummy material. The method of the present invention is a dry etching method for forming trenches or vias by removing a dummy material with its periphery surrounded by an interlayer oxide film, which method includes the steps of etching the dummy material to a predetermined depth, performing isotropic etching after the dummy material etching, and removing remaining part of the dummy material after the isotropic etching.
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