Fabrication of fused silica phase masks by reactive ion etching

摘要

A novel method for producing durable fused silica self -interference phase grating photomasks is described in tins paper. The grating pattern is formed into AZ-1350 photoresist by 325nm He-Cd laser optical holographic exposure and is transferred to a thin metal layer via focused ion beam lithography, then reactive ion etching in CHF3/O2 plasma is used to etch the fused silica substrate. Inspection performed by scanning electron microscopy (SEM) shows that the fabricated silica phase masks are perfect and no reactive deposition is formed in the grating grooves.