US Patent 11664232 Method and apparatus for plasma etching

A structure comprising a substrate and a component which forms involatile metal etch products is plasma etched. A structure comprising a substrate and a component which forms involatile metal etch products is provided. The structure is positioned on a support within a chamber having a first gas inlet arrangement comprising one or more gas inlets and a second gas inlet arrangement comprising one or more gas inlets. The structure is etched by performing a first plasma etch step using a first etch process gas mixture which is only introduced into the chamber through the first gas inlet arrangement. The structure is further etched by performing a second plasma etch step using a second etch process gas mixture which is only introduced into the chamber through the second gas inlet arrangement.