Etching method
AssigneeHitachi High-Tech Corporation
InventorsSumiko FUJISAKI, Kazunori SHINODA
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Abstract
An object of the present invention is to provide a technique of etching SiGe with respect to Ge with high selectivity. As one of etching methods in the present invention, the etching method for etching, as a processing object, a silicon germanium film of a film structure containing the silicon germanium film and a germanium film formed over a surface of a wafer, includes the steps of: supplying a hydrogen radical to the film structure while heating the wafer, and forming a modified layer over a surface of the film structure; and after the step of forming the modified layer, cooling the wafer to 0° C. to room temperature, supplying a gas containing sulfur hexafluoride or sulfur hexafluoride and argon to the modified layer and etching the silicon germanium film.
Claims8
An etching method for etching, as a processing object, a silicon germanium film of a film structure containing the silicon germanium film and a germanium film formed over a surface of a wafer, the etching method comprising the steps of:
- supplying a hydrogen radical to the film structure while heating the wafer, and forming a modified layer over a surface of the film structure;
- and
- after the step of forming the modified layer, cooling the wafer to 0° C. to room temperature, supplying a gas containing sulfur hexafluoride or sulfur hexafluoride and argon to the modified layer and etching the silicon germanium film.
Dependencies are inferred from the claim text.