Effect of hydrogen on dangling bond in a-Si thin film

Concentrations of the Si-H vibration bond and the dangling bond in amorphous silicon films were studied using FTIR and ESR techniques respectively as a function of annealing temperature in the range from 20 degrees C to 950 degrees C. It was found that the concentration of Si-H did not change much for temperatures up to 350 degrees C and then dropped monotonically and became negligible at temperatures above 850 degrees C, while the concentration of SiH(2) increased with temperature and attained a maximum at 450 degrees C and then decreased with temperature there after. The ESR signal dropped with temperature, up to 200 degrees C, and fell below the detection limit of our spectrometer in the range 200 degrees C-500 degrees C. The ESR signal recovered when annealing temperature was higher than 550 degrees C. The Si-H, SiH(2), ESR and optical absorption signals were found to be highly correlated to each other and could be interpreted in a consistent manner.