CORRELATION BETWEEN ELECTRON-MOBILITY AND SILICON-HYDROGEN BONDING CONFIGURATIONS IN PLASMA-HYDROGENATED POLYCRYSTALLINE SILICON THIN-FILMS

This letter describes the relationship between electron mobility and S i-hydrogen bonding configurations in poly-Si thin films after plasma-h ydrogenation treatment. A 50-nm-thick amorphous-Si film was crystalliz ed by excimer laser irradiation followed by plasma hydrogenation, Meas urements of the Hall effect and Raman scattering demonstrated that mob ility increased under the Si-H dominant state and decreased under the Si-H-2 dominant state, which were respectively caused by adjusted and excessive hydrogenation times. Mobility degradation was recovered by d issociation of excess H atoms by annealing. The origin of the correlat ion is discussed in terms of imperfections such as grain boundaries an d in-grain defects. (C) 1998 American Institute of Physics. [S0003-695 1(98)00419-7].