Cost-effective fabrication of a phase mask by direct etching of the laser-interference grating on fused silica substrate

Abstract

A simple and cost-effective method to manufacture a phase mask with high diffraction efficiency for deep UV application is proposed. The deep rectangular grating fabricated by using laser interference is etched directly into a fused silica substrate, instead of the dielectric coating on a substrate (done in a previous method). Using the metal layer on a dielectric layer for masking in the deep, dry etching process is also unnecessary in our technique. A fabricated rectangular grating with high diffraction efficiency is presented in this paper. We also demonstrate the fabrication processes and show the optimum parameters for our proposed technology. (C) 2003 Wiley Periodicals, Inc.