STOICHIOMETRY IN TI-N BARRIER LAYERS STUDIED BY X-RAY-EMISSION SPECTROSCOPY

Titanium nitride is an interesting material for use in microelectronic devices, particularly for use as a barrier layer. Considerable work has been done on these films and the relationship between the resistivity and film composition is now fairly well known, with the minimum resistivity occurring at the stoichiometric concentration. However, it is rather difficult to evaluate quantitatively the deviation of the film composition from the stoichiometry. We have produced Ti-N films with d. c. reactive sputtering at different nitrogen concentrations. These films were characterized with Auger electron spectroscopy and wavelength dispersive spectroscopy (WDS) and with X-ray diffraction. The experimental results of resistivity vs. WDS K alpha line shifts indicate a possible relationship between these two quantities. It could then be feasible to use the WDS K alpha line shifts for determining the resistivity of films near the stoichiometric composition.