Oxidation behavior of chromium nitride films

Abstract

Chromium nitride (CrN) films were deposited onto (100) silicon using a commercially available cathodic arc plasma deposition system. Oxidation of the films was conducted in air at temperatures ranging from 650 to 850 degrees C for 2 h. X-ray diffraction spectra revealed that Cr(2)O(3) diffraction peaks appeared above 650 degrees C and the relative integrated intensity of the oxide increased gradually with temperatures. Moreover, five vibration bands associated with Cr(2)O(3) were discerned in Raman spectra above this temperature. Nano-granular structure showed up at 650 degrees C, while abnormal grain growth resulting from the grain coalescence occurred above 800 degrees C. A thin dense oxide overlayer was present at 650 degrees C and the oxide thickness increased gradually with temperatures. Meanwhile, underneath CrN grains grew drastically above 700 degrees C and became more equiaxially-grained at 850 degrees C. The pre-exponential factor and activation energy of oxidation for CrN films were evaluated by analyzing the Arrhenius relation from the temperature dependence of oxide thickness. The obtained values were 1.3 x 10(-8) cm(2)/s and 110 +/- 6 kJ/mol, respectively, which is comparable to the literature data. (c) 2006 Elsevier B.V. All rights reserved.