Micro-optical elements fabricated by metal-transparent-metallic-oxides grayscale photomasks.

One-step gray-tone lithography is the most effective approach to making three-dimensional (3D) micro-optical elements (MOEs). Metal-transparent-metallic-oxide (MTMO) grayscale masks are novel and quite cost effective. In this paper, through the successful fabrication of 3D SiO(2) MOEs by gray-tone lithography and reactive ion etching, we thoroughly investigate the practical technique needs of MTMO grayscale masks on metallic nanofilms. Design calibration, pattern transfer, resolution, lifetime, and mask protection of grayscale masks have been verified. This work shows that the MTMO grayscale photomask has good practical applicability in the laboratory and in industry.