Nitrogen 1s charge referencing for Si 3 N 4 and related compounds

This paper describes the method used to produce a Si 3 N 4 standard for use as a reference material in XPS measurements of silicon nitride related compounds. The reference material was made by high dose ion implantation of N + into a (100) Si wafer and annealing the wafer at 1150°C. Rutherford back‐scattering measurements and an Auger depth profile confirmed that after the anneal a subregion of Si 3 N 4 was formed. X‐ray photoelectron spectroscopy (XPS) spectra were collected for Si 2p, N 1s and Si KLL lines. Signals from both elemental Si and Si 3 N 4 were observed, with no indication of specimen charging. The N 1s binding energy was determined to be 398.5 eV. Modified Auger parameter plots of the data showed results consistent with other careful measurements for Si and Si 3 N 4 . Because data from several studies indicate that the N 1s peak is relatively insensitive to minor compositional changes, the N 1s line can be used as a charge reference for the analysis of Si 3 N 4 ‐based materials. This charge reference can reduce the uncertainty in binding energy measurements on these generally insulating materials to ±0.1 eV.