Patent ID: 9373520
Filing Date: 2016-06-21
CPC Classification: H01J,H01L

Claim Text:
1. A method for etching a multilayer film formed by laminating a plurality of alternating layers of a first layer having a first dielectric constant and a second layer having a second dielectric constant, wherein a resist mask is formed on the multilayer film, the method comprising: etching the multilayer film by supplying an etchant gas into a processing chamber and supplying a microwave into the processing chamber to excite a plasma of the etchant gas; and reducing the resist mask by supplying an oxygen-containing gas and a fluorocarbon-based gas into the processing chamber and supplying a microwave into the processing chamber to excite a plasma of the oxygen-containing gas and the fluorocarbon-based gas and provide a trimming ratio (amount of the resist mask etched in a vertical direction)/(amount of the resist mask etched in a horizontal direction) which is close to 1, wherein said etching the multilayer film and said reducing the resist mask are alternately repeated.