Ultrathin SiON films with different nitrogen profiles grown by the plasma-enhanced CVD method and the rapid thermal nitridation (RTN) of SiO 2 with an NO gas have been analyzed by high-resolution angle-resolved photoelectron spectroscopy using bright synchrotron radiation to investigate interfacial chemistry and in-depth distribution of nitrogen atoms based on the second nearest neighbor effect of N 1s chemical shift. It is found that the CVD-deposited SiON film has a three-layer structure consisting of homogeneously-distributed N atoms in the [Si-Si 3-x N x ] 3 N chemical state, N atoms in the (Si-Si 3-x O x ) 3 N chemical state of about two monolayers, and the top SiO 2 layer. In contrast, N atoms in the NO-RTN SiON film exist at the SiON/Si interface as a double layer consisting of the [Si-Si 3-x N x ] 3 N lower layer and the (Si-Si 3-x O x ) 3 N upper layer with the concentration of 3.9×10 14 and 1.7×10 14 cm -2 , respectively, based on the N 1s chemical shift of about 0.6eV.
- Interfacial chemistry
- Interfacial structures
- Photoelectron spectroscopy
- Ultrathin Si oxynitride films