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

Abstract

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°C to 950°C. It was found that the concentration of Si-H did not change much for temperatures up to 350°C and then dropped monotonically and became negligible at temperatures above 850°C, while the concentration of SiH2 increased with temperature and attained a maximum at 450°C and then decreased with temperature there after. The ESR signal dropped with temperature, up to 200°C, and fell below the detection limit of our spectrometer in the range 200°C-500°C. The ESR signal recovered when annealing temperature was higher than 550°C. The Si-H, SiH2, ESR and optical absorption signals were found to be highly correlated to each other and could be interpreted in a consistent manner.