Mapping of Wafer Profile to Plasma Processing Conditions: Forward and Reverse Maps

Recent work by Vyvoda et al. (1998) and Lane et al. (1999) (among others) have resulted in phenomonological forward models that describe the profile of the structures from an etch process. In this paper, we quantify the reverse model and show that it is possible to use the profile information as inputs to compute (predict) the plasma conditions and chemistries. These predictions have an error in the range of 22%-79% depending on the plasma parameter under consideration. We propose that the algorithm could be usefully interfaced with a DOE tool to help process engineers select process recipes and conditions.