Combinatorial evaluation of dry semiconductor processes is described, including rotating a mask comprising a plurality of apertures, wherein the mask is positioned between a dry semiconductor processing source and the substrate, and performing a dry semiconductor process through the apertures of the mask at a plurality of intervals during the rotating the mask to combinatorially create a plurality of processed regions on the substrate, wherein the apertures of the mask are arranged in such a way that the plurality of processed regions have different geometries relative to the processing source, and analyzing the processed regions to determine effects of time and geometry on the processed regions.