Patent ID: 9425094
Filing Date: 2016-08-23
CPC Classification: H01L

Claim Text:
1. A method for forming a semiconductor device structure, comprising: forming a dielectric layer over a semiconductor substrate; forming a hard mask layer over the dielectric layer, wherein the hard mask layer is a metal-containing layer; performing a plasma etching process to etch the hard mask layer to form an opening, wherein a gas mixture used in the plasma etching process includes a nitrogen-containing gas, a halogen-containing gas, and a carbon-containing gas, the gas mixture has a volumetric concentration of the nitrogen-containing gas in a range from about 20% to about 30%, and a volumetric concentration ratio of the carbon-containing gas to the halogen-containing gas in the gas mixture is equal to about 0.3; etching the dielectric layer through the opening in the hard mask layer to form a feature opening in the dielectric layer; and forming a conductive material in the feature opening.