A photomask and method for coating a backside of the same with an
antireflective material are disclosed. The photomask includes a
transparent substrate with a front-side and a backside. The front-side
absorber layer has a patterned absorber layer formed thereon. An
anti-reflective layer is deposited on the backside of the substrate. More
particularly, the antireflective coating may have a refractive index
between 1.4 and 1.8. The anti-reflective layer allows the photomask to
reduce unwanted reflections within a lithography system and therefore
improve system efficacy and throughput.
