Wet oxidation of Ti34Si23N43 thin films with and without pre-annealing

2019-11-12 13:23:05

matrix oxidation oxide annealing grains

责任者: Kacsich, T.;Gasser, S.M.;Garland, C.;Nicolet, M.-A. 单位: California Inst. of Technol., Pasadena, CA, USA 来源出处: Surface and Coatings Technology(Surf. Coat. Technol. (Switzerland)),2000/02/21,124(2-3):162-8 摘要: Films of a ternary alloy of composition Ti34Si23N43 and of a structure consisting of homogeneously distributed ~2 nm sized TiN-like grains in an amorphous matrix were deposited by reactive magnetron sputtering to thicknesses of 250-1000 nm and then oxidized with steam at 600, 800, or 1000°C, with and without first annealing the film in vacuum at 800°C for 1 h. The microstructure of the nitride and the oxide was analyzed by X-ray diffraction and plan-view transmission electron microscopy. The thickness of the grown oxide scale was monitored by backscattering spectrometry. At 600 and 800°C, the oxide scale has the composition of Ti20Si13O67, corresponding to a full and lossless oxidation of Ti and Si to TiO2 and SiO2. During that process, the nano-grains in the alloy grow several-fold. The oxide is also a two-phase mixture of TiO2 nano-grains in an amorphous matrix. As a function of the oxidation duration, t, the oxide grows in a log(t)-like fashion. Pre-annealing in vacuum reproduces the growth of TiN grains in the alloy observed during oxidation. This structural change does not alter the log(t)-type dependence but drastically reduces the rate of oxidation. The observations are interpreted as resulting from the compositional changes of the matrix induced by the growth of the TiN grains in the alloy 关键词: amorphous state;annealing;grain growth;grain size;humidity;nanostructured materials;oxidation;reaction kinetics;Rutherford backscattering;silicon compounds;sputtered coatings;titanium compounds;transmission electron microscopy;X-ray diffraction;Ti34Si23N43 thin films;wet oxidation;pre-annealing;nm-sized TiN-like grains;grain distribution;amorphous matrix;reactive magnetron sputtering;oxidation;vacuum film annealing;nitride microstructure;oxide microstructure;X-ray diffraction;plan-view TEM;plan-view transmission electron microscopy;oxide scale thickness;backscattering spectrometry;Ti20Si13O67;Ti lossless oxidation;Si lossless oxidation;nano-grains growth;oxide two-phase mixture;TiO2 nano-grains;oxidation duration;oxide growth law;vacuum pre-annealing;oxidation rate reduction;matrix compositional evolution;600 to 800 C;1 h;250 to 1000 nm;Ti-Si-N