IR, ESR and resistivity measurements on amorphous silicon oxi-nitride films prepared by PECVD at low temperature

We have measured IR and ESR absorption spectra and the resistivity of SiO x N y H z films grown by PECVD of SiH 4 and N 2 O. For x ≅ 2, we have Si-O, O-H and N-H bands in the IR spectrum and a single narrow line in the ESR spectrum attributed to non-bridging oxygen centers with g = 2.0007. The hopping conductivity is low (210 −17 Ω −1 cm −1 ). The results lead us to propose that for x between 0.7 and 1.2, our samples present SiO x H z and SiN y H z separated zones. The first where OSiO 2 Si, HSiO 3 and HSiO 2 Si configurations observed in the IR spectrum correspond to the centers found at g ≅ 2.001 in the ESR spectrum (· SiO 3 and ·SiO 2 Si). The second where NSiN 2 Si, NSiNSi 2 , HSiN 2 Si and HSiNSi 2 configurations of the IR spectrum give rise to ·SiN 2 Si and ·SiNSi 2 ESR centers (g between 2.0034 and 2.0043). In these silicon rich materials, the hopping conductivity remains low (8 10 −17 Ω −1 cm −1 )