Quantitative analysis of PECVD processed silicon nitride thin films using AES, XPS and spectroscopic ellipsometry (SE)

Full text: A series of silicon nitride films with different N/Si composition ratio has been prepared by PECVD. Quantitative XPS analysis of Si 2p gives a clearly picture of changing of bond states (e.g., Si-N and Si-Si) in the films, which is also consistent with AES prediction of composition. Optical properties characterizations using SE combined with an empirical dielectric function show that, as the N/Si ratio increases, the k value decreases from 1.5 to 0.3 while the 'n' value increases slightly around 2.2 at 193nm. The shift of the optical absorption edge is also varied by a change of valence band structure