| abstract |
Improved methods and apparatus for removing a metal nitride selectively with respect to exposed or underlying dielectric or metal layers are provided herein. In some embodiments, a method of etching a metal nitride layer atop a substrate, includes: (a) oxidizing a metal nitride layer to form a metal oxynitride layer (MN1-xOx) at a surface of the metal nitride layer, wherein M is one of titanium or tantalum and x is an integer from 0.05 to 0.95; and (b) exposing the metal oxynitride layer (MN1-xOx) to a process gas, wherein the metal oxynitride layer (MN1-xOx) reacts with the process gas to form a volatile compound which desorbs from the surface of the metal nitride layer. |