NOVELTY - The method involves etching a pattern from a patterned photoresist layer into an anti-reflective layer using a first plasma. The pattern is etched from the layer into another anti-reflective layer using a second plasma. The former anti-reflective layer is removed using a third plasma. The pattern is etched from the latter anti-reflective layer into a metal hard mask layer (204) using a fourth plasma. The latter anti-reflective layer is removed using a fifth plasma. The plasmas are formed from five process gases, where the four of the gases comprise chlorine.    USE - Method for processing a metal hard mask layer i.e. titanium nitride hard mask, in a substrate e.g. silicon substrate, lll-V compound substrate, silicon germanium substrate, epi-substrate, silicon-on-insulator substrate, display substrate such as LCD, plasma display, electro luminescence (EL) lamp display, LED substrate, a solar cell array and solar panel. Can also be used for processing a silicon dioxide, a silicon oxynitride such as silicon nitride, a silicide such as titanium silicide and nickel silicide.    ADVANTAGE - The method enables increasing productivity and efficiency of processing substrates by providing process. The method enables performing etch process and removal of etch residues and etch mask materials in a single process chamber utilizing similar etching chemistries. The method enables providing faster removal of etch residues and excess etch mask material over conventional etch techniques, thus facilitating improved control over critical dimension of etched features.    DETAILED DESCRIPTION - The former anti-reflective layer comprises an organic anti-reflective layer such as carbon-rich anti-reflective coating (ARC) and a bottom ARC (BARC). The latter anti-reflective layer is a silicon-based anti-reflective layer such as silicon nitride, silicon oxynitride and Si-rich ARC layer. One of the process gases comprises ethylene, argon and helium.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of a substrate during different stages of a processing sequence.    Substrate (202)    Metal hard mask layer (204)    Openings (212)