J. Phys. IV France 10 (2000) Pr7-259-Pr7-262
Raman scattering investigation of the structure of amorphous silicon in a-Si/SiO2 superlattice filmsY. Wang1, O. Matsuda2, T. Serikawa3 and K. Murase1
1 Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikanayama, Toyonaka, Osaka 560-0043, Japan
2 Division of Applied Physics, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, Japan
3 NTT Electronics, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0124, Japan
To clarify the structure of amorphous silicon (a-Si), with the thickness less than 5 nm, affected by the interface between a-Si and a-SiO2 as well as the structural changes after an annealing of 900°C in N2 gas atmosphere, Raman scattering investigation is carried out in a-Si/SiO2 superlattice (SL) films prepared by the sputtering method. Vibrational motion of strained a-Si at and near a-Si/SiO2 interface is influenced by the vibration of pressed a-SiO2 at the other side of the interface that results a blue shift of transverse optic (TO) -like modes in a-Si. The narrow space of thin (<2.5 nm in this work) a-Si layer impedes the crystallization to c-Si and the relaxation of energy during the crystallization event.
© EDP Sciences 2000