Metal hard mask layers for processing of microelectronic workpieces

A method of processing microelectronic workpieces, comprising:

• forming a hard mask layer over one or more underlying layers on a substrate, the substrate being part of a microelectronic workpiece, the hard mask layer comprising at least one of SiN, SiO2, or SiON;
• forming a ruthenium metal hard mask layer on the hard mask layer;
• etching the ruthenium metal hard mask layer to provide a patterned ruthenium metal hard mask layer, and wherein the etching of the ruthenium metal hard mask layer exposes the hard mask layer;
• etching the hard mask layer through the patterned ruthenium metal hard mask layer to form a patterned hard mask layer;
• etching the one or more underlying layers through the patterned ruthenium metal hard mask layer and the patterned hard mask layer, the method further comprising, after etching of the ruthenium metal hard mask layer and prior to etching of the hard mask layer forming an organic planarization layer (OPL) and an antireflective coating layer (ARC) above the patterned ruthenium metal hard mask layer.