Method for etching organic low-k dielectric using ammonia, NH3, as an active
etchant. Processes using ammonia results in at least double the etch rate of organic
low-k dielectric materials than processes using N2/H2 chemistries, at similar process
conditions. The difference is due to the much lower ionization potential of NH3
versus N2 in the process chemistry, which results in significantly higher plasma
densities and etchant concentrations at similar process conditions.
