Abstract: Methods for forming patterned multi-layer stacks including a metal-containing layer are provided herein. Methods involve using silicon-containing non-metal materials in a multi-layer stack including one sacrificial layer to be later removed and replaced with metal while maintaining etch contrast to pattern the multi-layer stack and selectively remove the sacrificial layer prior to depositing metal. Methods involve using silicon oxycarbide in lieu of silicon nitride, and a sacrificial non-metal material in lieu of a metal-containing layer, to fabricate the multi-layer stack, pattern the multi-layer stack, selectively remove the sacrificial non-metal material to leave spaces in the stack, and deposit metal-containing material into the spaces. Sacrificial non-metal materials include silicon nitride and doped polysilicon, such as boron-doped silicon.