title: MTMO grayscale photomask.
abstract: We present a new class of simple, cheap and stable grayscale photomasks based on the metal-transparent-metallic-oxides (MTMO) systems by laser direct writing in metal films. For obtaining high resolution and grainless grayscale patterns we developed a refinement method of the films, in which the nanometer size effect may play a significant role for the improvement. We propose a layered oxidation model and a grain model for the mechanism of In- and Sn-based MTMO systems. The masks have a wide application wavelength range at least from 350 to 700 nm. Three-dimensional microstructures have been successfully fabricated by using the MTMO grayscale masks.
authors.affiliation: National Center for Nanoscience and Technology, No 11, Beiyitiao, Beijing 100190, China.
authors.forename: Chuan Fei
authors.initials: CF
authors.lastname: Guo
authors.forename: Jianming
authors.initials: J
authors.lastname: Zhang
authors.forename: Junjie
authors.initials: J
authors.lastname: Miao
authors.forename: Yongtao
authors.initials: Y
authors.lastname: Fan
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu