Effect of post-hydrogenation on the structural properties of amorphous silicon network

Post-hydrogenation of magnetron sputtered amorphous silicon films has been carried out with the aim to study the effect of hydrogen interaction with amorphous silicon network on its short and medium range order. Raman spectroscopy has been used to study the variations in the amorphous structure. Nuclear reaction analysis (NRA) has been used to determine the total amount and depth distribution of the penetrated hydrogen atoms. The concentration of the silicon-bonded hydrogen and the bonding configurations have been established by means of infrared (IR) transmission measurements. The values of hydrogen concentration evaluated by NRA and IR spectroscopy coincide within the measurement accuracy, suggesting that the hydrogen diffusion proceeds via interaction with the host silicon atoms. This interaction is accompanied by a rearrangement of the strained Si-Si bonds which leads to an improvement of the amorphous network.