Process for etching dielectric films with improved resist and/or etch profile characteristics

摘要

A process of etching openings in a dielectric layer includes supporting a semiconductor substrate in a plasma etch reactor, the substrate having a dielectric layer and a patterned photoresist and/or hardmask layer above the dielectric layer; supplying to the plasma etch reactor an etchant gas comprising (a) a fluorocarbon gas (C_xF_yH_z, where x≧1, y≧1, and z≧0), (b) a silane-containing gas, hydrogen or a hydrocarbon gas (C_xH_y, where x≧1 and y≧4), (c) an optional oxygen-containing gas, and (d) an optional inert gas, wherein the flow rate ratio of the silane-containing gas to fluorocarbon gas is less than or equal to 0.1, or the flow rate ratio of the hydrogen or hydrocarbon gas to fluorocarbon gas is less than or equal to 0.5; energizing the etchant gas into a plasma; and plasma etching openings in the dielectric layer with enhanced photoresist/hardmask to dielectric layer selectivity and/or minimal photoresist distortion or striation.