Method of etching extreme ultraviolet light (EUV) photomasks

Embodiments of methods of etching EUV photomasks are provided herein. In one embodiment, a method of etching an extreme ultraviolet photomask includes providing a photomask comprising, in order, a substrate, a multi-material layer, a capping layer, and a multi-layer absorber layer, the multilayer absorber layer comprising a self-mask layer disposed over a bulk absorber layer, wherein the self-mask layer comprises tantalum and oxygen and the bulk absorber layer comprises tantalum and essentially no oxygen; etching the self-mask layer using a first etch process; and etching the bulk absorber layer using a second etch process different than the first, wherein the etch rate of the bulk absorber layer is greater than the etch rate of the self-mask layer during the second etch process.