INTEGRATED ATOMIC LAYER PASSIVATION IN TCP ETCH CHAMBER AND IN-SITU ETCH-ALP METHOD

A plasma processing system includes a chamber having a coil disposed above a dielectric window for providing radio frequency power to the processing region. An etch gas delivery system is coupled to gas sources used for a first etch of a material. A liquid delivery system includes a source of liquid precursor, a liquid flow controller, and a vaporizer. A controller activates the etch gas delivery system to perform the first etch and activates the liquid delivery system to perform an atomic layer passivation (ALP) process after the first etch to coat features with a conformal film of passivation. Each time the ALP process is completed a single atomic monolayer of the conformal film of passivation is formed. The controller activates the etch gas delivery system to perform a second etch, with the conformal film of passivation protecting the mask and sidewalls of the features during the second etch.