Method of adjusting the minimum line width uniformity in the etching process

A method for etching a metal layer deposited on a substrate to form features with desired profile and uniform critical dimensions (CD) for the feature on the substrate. In one embodiment, a method for etching a material layer disposed on the substrate is flushed with a gas mixture comprising the steps of: providing a substrate metal layer is disposed over the etch reactor, at least one chlorine-containing gas and a passivation gas into the reactor using a plasma formed from the send step, and a gas mixture comprising a step of etching the metal layer, the passivation gas includes a nitrogen gas and an unsaturated hydrocarbon gas, nitrogen gas and the unsaturated hydrocarbon gas is about 1: 3 to about 20: 1 It has a gas flow rate ratio between.