Hi dear members, I need to reduce the back reflection during my lithograpy. I do know there are a lot of antireflective coating polymer available commercially. But I am still wondering what is the principle behind? Is it because those materials have large absorption coefficient or because the thickness is controlled to be half wavelength? Also, will the antireflective coating block everything reflected back or only those are not normal to the interface? Thanks! Peng Yao DOEs lab Electrical Engineering Dept. Univeristy of delaware Newark D.E 19716