title: Fabrication and Gas-Sensing Properties of Ni-Silicide/Si Nanowires.
abstract: Ni-silicide/Si nanowires were fabricated by atomic force microscope nano-oxidation on silicon-on-insulator substrates, selective wet etching, and reactive deposition epitaxy. Ni-silicide nanocrystal-modified Si nanowire and Ni-silicide/Si heterostructure multi-stacked nanowire were formed by low- and high-coverage depositions of Ni, respectively. The Ni-silicide/Si Schottky junction and Ni-silicide region were attributed high- and low-resistance parts of nanowire, respectively, causing the resistance of the Ni-silicide nanocrystal-modified Si nanowire and the Ni-silicide/Si heterostructure multi-stacked nanowire to be a little higher and much lower than that of Si nanowire. An O2sensing device was formed from a nanowire that was mounted on Pt electrodes. When the nanowires exposed to O2, the increase in current in the Ni-silicide/Si heterostructure multi-stacked nanowire was much larger than that in the other nanowires. The Ni-silicide nanocrystal-modified Si nanowire device had the highest sensitivity. The phenomenon can be explained by the formation of a Schottky junction at the Ni-silicide/Si interface in these two types of Ni-Silicide/Si nanowire and the formation of a hole channel at the silicon nanowire/native oxide interface after exposing the nanowires to O2.
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, 145 Xingda Rd., Taichung, 40227, Taiwan. hfhsu@dragon.nchu.edu.tw.
authors.forename: Hsun-Feng
authors.initials: HF
authors.lastname: Hsu
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, 145 Xingda Rd., Taichung, 40227, Taiwan.
authors.forename: Chun-An
authors.initials: CA
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, 145 Xingda Rd., Taichung, 40227, Taiwan.
authors.forename: Shang-Wu
authors.initials: SW
authors.lastname: Liu
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, 145 Xingda Rd., Taichung, 40227, Taiwan.
authors.forename: Chun-Kai
authors.initials: CK
authors.lastname: Tang
keywords: Nanowire; Scanning probe lithography; Schottky barrier; Sensor; Si; Silicide