The Karl Suss MA-6 Contact Aligner system can perform precision mask-to-wafer front- or back-side alignment and near-UV photoresist exposure in hard- and soft- contact, as well as high and low vacuum contact; proximity is not available. Our current configuration accommodates 3", 4" and 6" wafers and pieces. SNF has two MA-6 aligners (karlsuss and karlsuss2).
This drawing of the chuck vacuum channels will help in designing placement of alignment marks for backside wafer alignment. Alignment marks which land on the vacuum channels will not be visible using the backside microscope.