Kilpatrick Townsend & Stockton LLP
Tungsten oxide processing
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.
Applied Materials, Inc.
H H H
H01L H01J H01J
inventional inventional inventional
Xikun Seung Jie Anchuan Nitin K. Mikhail
Wang Park Liu Wang Ingle Korolik