Raman and ultraviolet–visible spectroscopy of titanium chromium nitride thin films

Abstract

Titanium chromium nitride (TiCrN) films were prepared under various nitrogen flow rates (7–18 sccm) via co-sputtering. It was argued that the target poisoning effect governs the deposition process in nitrogen-rich atmospheres. The observed X-ray diffraction patterns suggested that the crystal structure of TiCrN coatings is a cubic close-packed (TiCr)N solid solution with (111) crystalline planes. The patterns also implied that the increased nitrogen content is accompanied by a tendency towards crystallite size enlargement. In addition to the main vibrational transitions, the micro-Raman spectroscopy detected the Raman third-order vibrational transition (2A + O) and a peak corresponding to one of the Raman second-order transitions (A + O). It was also revealed that the area under the peaks corresponding to chromium nitride first-order and second-order acoustic vibrational transitions increase with the increase in the nitrogen content of the samples. Ultraviolet–visible spectroscopy showed that the coatings can have a potential application in under-marine UV photodetector designs.