PVD ALN film with oxygen doping for a low etch rate hardmask film

摘要

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.

主权项

1. A method of making a hardmask, comprising:
sputtering an aluminum target in an atmosphere containing an inert gas, a nitrogen containing gas, and an oxygen containing gas to deposit an oxygen doped polycrystalline aluminum nitride material, wherein the amount of nitrogen containing gas is more than two times the amount of oxygen containing gas; and patterning the oxygen doped polycrystalline aluminum nitride material to form the hardmask.