Patent attributes
A plasma processing method is provided for etching a multilayer film having a first film and a second film with differing dielectric constants alternatingly stacked on a substrate, and forming a hole with a predetermined shape in the multilayer film. The plasma processing method includes a first step of etching the multilayer film to a first depth using a gas mixture containing a CF based gas at a first flow rate and a bromine-containing gas, a chloride-containing gas, and/or an iodine-containing gas; a second step of etching the multilayer film to a second depth after the first step using a gas mixture containing the CF based gas at a second flow rate and the bromine-containing gas, the chloride-containing gas, and/or the iodine-containing gas; and a third step for over etching the multilayer film after the second step until the hole reaches a base layer.
