The present invention generally relates to a doped aluminum nitride hardmask and a method of making a doped aluminum nitride hardmask. By adding a small amount of dopant, such as oxygen, when forming the aluminum nitride hardmask, the wet etch rate of the hardmask can be significantly reduced. Additionally, due to the presence of the dopant, the grain size of the hardmask is reduced compared to a non-doped aluminum nitride hardmask. The reduced grain size leads to smoother features in the hardmask which leads to more precise etching of the underlying layer when utilizing the hardmask.
