Sputtered Fe[sub 2]O[sub 3] Films for Use in “See Through” Masks

Abstract
A sputtering technique has been devised for preparing films with rates of solubility in and with transmission spectra appropriate for use as “see‐through” photomasks (i.e., photomasks sufficiently transparent at 589 nm for viewing purposes and opaque in the spectral region 360–400 nm). This method involves rf or d‐c sputtering of Fe electrodes in mixturesor rf sputtering of electrodes in mixtures. To achieve films with acceptable transmission spectra the content must not exceed 82% with the metal electrode and must not exceed 87% with the oxide electrode. The fastest deposition rate obtained was 120 Å/min for 350W input rf power using an Fe electrode and an ambient. Measurements of scratch resistance, defect density, and film morphology are presented.