On the effect of bonded hydrogen in the local microstructure of PECVD SiN_x:H films

The effect of bonded hydrogen in the atomic microstructure of nitrogen-rich SiNx films is investigated using EXAFS. It is shown that when the hydrogen concentration is of the order of 30 at%, the measured NSi bond length is shorter than that in the reference nitride by 2-3% and the coordination number in the 1st neighbor shell is significantly lower than the expected value of 3. Furthermore, evidence is provided on the coexistence of an a-Si phase, the concentration of which depends on the deposition conditions. © 1995.