| 摘要 |
Disclosed is an etching method. The etching method includes preparing a substrate where a pattern is formed on the substrate, DiSilane (DS) oxide is formed at a side of the pattern, and DiCloroSilane (DCS) oxide covers upper portions of the pattern and the DS oxide; primarily etching the DCS oxide using a medium having a first DCS/DS etching selectivity; and secondarily etching the DCS oxide and the DS oxide using a medium having a second DCS/DS etching selectivity lower than the first DCS/DS etching selectivity. Accordingly, the etching method can solve the following problems that an upper portion of a poly-silicon pattern is partially etched so that damage occurs, an etch residue is generated when the etching is performed at a high DCS/DS selectivity, and a difference in an etch amount occurs caused by loading effect of a dense pattern part and a rough pattern part. [Reference numerals] (AA) Start; (BB) End; (S110) Prepare a substrate; (S120) Etch DCS oxide; (S130) Etch DCS oxide and DS oxide |
