Microstructure and Optical Characterization of Magnetron Sputtered NbN Thin Films
Some fundamental studies on the preparation, structure and optical properties of NbN films were carried out. NbN thin films were deposited by DC reactive magnetron sputtering at different N2 partial pressures and different substrate temperatures ranging from -50 ℃to 600 ℃. X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) were employed to characterize their phase components, microstructures, grain sizes and surface morphology. Optical properties inclusive of refractive indexes, extinction coefficients and transmittance of the NbN films under different sputtering conditions were measured. With the increase in the N2 partial pressure,δ-NbN phase structure gets forming and the grain size and lattice constant of the cubic NbN increasing. The deposited NbN film has relatively high values of refractive index and extinction coefficient in the wavelength ranging from 240 nm to 830 nm. Substrate temperature exerts notable influences on the microstructure and optical transmittance of the NbN films. The grain sizes of the δ-NbN film remarkably increase with the rise of the substrate temperature, while the transmittance of the films with the same thickness decreases.Ultra-fine granular film with particle size of several nanometers forms when the substrate is cooled to -50 ℃, and a remarkable augmentation of transmittance could be noticed under so low a temperature.
作 者： DU Xin-kang WANG Tian-min WANG Cong CHEN Bu-liang ZHOU Long 作者单位： DU Xin-kang(School of Science, Beijing University of Aeronautics and Astronautics, Beijing 100083, China;Mechanical Engineering College, Shijiazhuang 050003, China)WANG Tian-min,WANG Cong,ZHOU Long(School of Science, Beijing University of Aeronautics and Astronautics, Beijing 100083, China)
CHEN Bu-liang(Academy of Space Technology, Beoing 100029, China)
刊 名： 中国航空学报(英文版) ISTIC 英文刊名： CHINESE JOURNAL OF AERONAUTICS 年，卷(期)： 2007 20(2) 分类号： V2 关键词： reactive magnetron sputtering NbN thin film microstructure optical properties