Spatial profiles of neutral, ion, and etch uniformity in a large-area high-density plasma reactor

Spatial profiles of neutral density, ion density, and etch rate have been m easured in a large-area high-density plasma reactor. Blanket photoresist fi lms on 200 mm wafers are etched by oxygen plasmas in a magnetized inductive ly coupled plasma reactor. Ion density and relative neutral density are mea sured by a scanning Langmuir probe and optical probe, respectively. Spatial ly resolved atomic oxygen density is then measured by optical emission spec troscopy and spatially resolved actinometry. The etch rate is calculated fr om film thickness measurements taken before and after the wafer is exposed to the oxygen plasma. Ion energy and wafer surface temperature were also me asured. The mechanism linking neutral density, ion density, and etching rat e is discussed. (C) 2001 American Institute of Physics.