ADJUSTABLE REMOTE DISSOCIATION

摘要

Methods of selectively etching an exposed portion of a patterned substrate relative to a second exposed portion are described. The etching process is a gas phase etch which uses an oxidizing precursor unexcited in any plasma prior to combination with plasma effluents formed in a remote plasma from an inert precursor. The plasma effluents may be combined with the oxidizing precursor in a plasma-free remote chamber region and/or in a plasma-free substrate processing region. The combination of the plasma effluents excites the oxidizing precursor and removes material from the exposed portion of the patterned substrate. The etch rate is controllable and selectable by adjusting the flow rate of the oxidizing precursor or the unexcited/plasma-excited flow rate ratio.