Tungsten oxide processing

摘要

Methods of selectively etching tungsten oxide relative to tungsten, silicon oxide, silicon nitride and/or titanium nitride are described. The methods include a remote plasma etch using plasma effluents formed from a fluorine-containing precursor in combination with ammonia (NH3). Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten oxide. The plasmas effluents react with exposed surfaces and selectively remove tungsten oxide while very slowly removing other exposed materials. Increasing a flow of ammonia during the process removes a typical skin of tungsten oxide having higher oxidation coordination number first and then selectively etching lower oxidation tungsten oxide. In some embodiments, the tungsten oxide etch selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region.

主权项

1. A method of etching tungsten oxide, the method comprising:
flowing a fluorine-containing precursor and ammonia (NH3) into a remote plasma region fluidly coupled to a substrate processing region via through-holes in a showerhead while forming a remote plasma in the remote plasma region to produce plasma effluents; and etching the tungsten oxide from a substrate disposed within the substrate processing region by flowing the plasma effluents into the substrate processing region through the through-holes in the showerhead.