Theoretical modeling on hydrogen evolution in ultraviolet light-treated hydrogenated silicon nitride

• Published in: Journal of applied physics 2008-11, Vol.104 (9), p.094103-094103-5
• Main Authors: Sun, Rong, Wang, Lei, Cheng, Jing, Michel, Jurgen, Kimerling, Lionel, Balseanu, Mihaela, Xia, Li-Qun, M'saad, Hichem
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.3007989

Ultraviolet light illumination is shown experimentally to be able to induce hydrogen evolution in hydrogenated amorphous silicon nitride ( a -Si x N y H z ) film and the total hydrogen (H) removal percentage depends strongly on the composition with a maximum with balanced silicon-hydrogen and nitride-hydrogen single bonds (Si-H/N-H ratio equals to 1). We developed a general model for analyzing H removal in such alloyed glass system. Our statistical Monte Carlo models reveal that H 2 evolution is the result of highly selective chemical reactions among nearest neighbor SiH and NH bonds in a -SiN x H y , which leads to formation of Si-N bonds. This process is sensitive to its local chemical environment. The nearest neighbor coordination number and the presence of SiH 2 and NH 2 groups in a -Si x N y H z network have impact on the total H removal. Our model gives quantitative measures for all the corresponding reaction constants, consistent with experimental observations.