ELECTRON-ENERGY-LOSS FINE-STRUCTURE MEASUREMENTS OF SILICON-NITRIDE FILMS

Nitrogen K-edge electron energy loss near-edge structure (ELNES) spect ra of thin SiNx films were measured with a small scattering angle in t he reflection mode for the first time. The SiNx films were formed by l ow pressure chemical vapour deposition (LPCVD) on silicon oxide layers with or without rapid thermal nitridation (RTN) pretreatment. The ELN ES spectra were found to be similar to the X-ray absorption near-edge structure (XANES) spectra, and to be sensitive to the outermost SiNx s tructures. The ELNES spectra of the silicon oxide and SiNx films with RTN pretreatment were similar and independent of the thickness. The EL NES spectra of the SiNx films with RTN pretreatment and a thicker SiNx film (7.7 nm) without RTN pretreatment were also similar. However, ve ry thin SiNx films (thickness, 0.4 or 0.6 nm) without RTN pretreatment showed slightly different ELNES spectra from the thicker film without RTN pretreatment and SiNx films with RTN pretreatment.