Effects of surface conditions of the Focus Ring on etching uniformity

We developed an original model for the organic-film etching process of the argon-oxygen plasma with using a radical reaction analysis and a two-dimensional plasma simulation model. The motivation of this study is to examine the effects of surface conditions of the ring-shaped part around a wafer (Focus Ring) on the uniformity of etching characteristics. From the simulation results, it has been verified that etching rates at the wafer edge strongly depend on surface conditions of the Focus Ring. Finally, we found that the controlling the surface conditions of the Focus Ring, which are the surface material and the surface temperature, is important to improve the uniformity in further etching processes.