摘要 |
A plasma etch process is described for the etching of oxide with a high selectivity to nitride, including nitride formed on uneven surfaces of a substrate, e.g., on sidewalls of steps on an integrated circuit structure. The addition of a hydrogen-bearing gas to C4F8 or C2F6 etch gases and a scavenger for fluorine, in a plasma etch process for etching oxide in preference to nitride, results in a high selectivity to nitride which is preserved regardless of the topography of the nitride portions of the substrate surface.
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