title: Grayscale photomask fabricated by laser direct writing in metallic nano-films.
abstract: The grayscale photomask plays a key role in grayscale lithography for creating 3D microstructures like micro-optical elements and MEMS structures, but how to fabricate grayscale masks in a cost-effective way is still a big challenge. Here we present novel low cost grayscale masks created in a two-step method by laser direct writing on Sn nano-films, which demonstrate continuous-tone gray levels depended on writing powers. The mechanism of the gray levels is due to the coexistence of the metal and the oxides formed in a laser-induced thermal process. The photomasks reveal good technical properties in fabricating 3D microstructures for practical applications.
authors.affiliation: National Center for Nanoscience and Technology, China, No. 11Beiyitiao, Zhongguancun, Beijing100190, China.
authors.forename: Chuan Fei
authors.initials: CF
authors.lastname: Guo
authors.forename: Sihai
authors.initials: S
authors.lastname: Cao
authors.forename: Peng
authors.initials: P
authors.lastname: Jiang
authors.forename: Ying
authors.initials: Y
authors.lastname: Fang
authors.forename: Jianming
authors.initials: J
authors.lastname: Zhang
authors.forename: Yongtao
authors.initials: Y
authors.lastname: Fan
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Wang
authors.forename: Wendong
authors.initials: W
authors.lastname: Xu
authors.forename: Zhensheng
authors.initials: Z
authors.lastname: Zhao
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
mesh_terms: D007834:Lasers; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry / Q000528:radiation effects* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D011829:Radiation Dosage; D013499:Surface Properties; D014001:Tin / Q000737:chemistry / Q000528:radiation effects*
chemical_list: D008567:Membranes, Artificial; D014001:Tin