METHOD FOR ACHIEVING ULTRA-HIGH SELECTIVITY WHILE ETCHING SILICON NITRIDE

Apparatuses for processing substrates are provided herein. Apparatuses include a plasma etch chamber having a showerhead and pedestal for holding a substrate having silicon nitride, at least one outlet for coupling to a vacuum, a solid non-functional silicon source, and a plasma generator. A solid silicon source may be upstream of a substrate, such as at or near a showerhead of a process chamber, or in a remote plasma generator. Apparatuses also include a plasma etch chamber, at least one outlet, a solid non-functional silicon source, a plasma generator, and a controller for controlling operations including instructions for causing introduction of a fluorinating gas and causing ignition of a plasma to form fluorine-containing etching species in the plasma etch chamber.