Patterning and Reactive Ion Etching of Diamond Films using Light Coupling Masks

Abstract

AbstractWe describe the novel application of light coupling masks (LCM) in the lithographic patterning of fine structures in diamond films. A PDMS mask was used in the exposure of complex patterns of gratings in AZP 1205 resist on a substrate of Al/ diamond. The profiles of these grating patterns were then modified on a localized scale by a process of reflow of the resist. We report on the transfer of the patterns formed in resist by the LCMs into the diamond film using a sputtered Al layer as a mask. The two-stage process comprised etching of the pattern into the Al followed by transfer into the diamond film using CF4/ O2 and CHF3/ O2 gases. The presence of O2 in the CF4/ O2 and CHF3/ O2 gas mixtures produced Al oxides on the surface of the mask. The etch selectivity of the mask was greater in CF4/ O2 than in CHF3/ O2 gases and was only weakly dependent on the concentration of O2 (0-12 sccm).