Effects of hydrogen on structure and crystallization behavior of sputter-deposited amorphous germanium films. (2nd July 2020)

• Record Type: Journal Article
• Authors: Hanya, Yuki; Nakamura, Ryusuke; Okugawa, Masayuki; Ishimaru, Manabu; Oohata, Goro; Yasuda, Hidehiro
• Is Part Of: Japanese journal of applied physics. Volume 59:Number 7(2020)
• Publication Date: 2020-07-02
• Subjects: amorphous Ge -- hydrogeneration -- thin film -- crystallization -- transmission electron microscopy; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/ab9cd9
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We examined by transmission electron microscopy the structure and crystallization behavior of hydrogenerated and non-hydrogenerated amorphous germanium films (a-Ge:H and a-Ge) prepared by sputtering to figure out the effects of hydrogen on them. In pair-distribution function, first and second peaks at the interatomic distance of 0.26 and 0.40 nm, respectively, were found to be higher and sharper in a-Ge:H than in a-Ge; therefore amorphous structure was organized in a more ordered state within a short range by hydrogeneration. On thermal annealing, fine nanograins (FGs) of about 10 nm in size appeared preferentially at 350 °C and above in a-Ge:H, which is in contrast with the formation of coarse particles of about 100 nm in size at 500 °C in a-Ge. Hydrogeneration would make a certain number of short-range ordered clusters distributed in the amorphous matrix, inducing the preferential formation of FGs at lower temperatures.