摘要
Chromium nitride （Cr2N） thin films were prepared by a DC magnetron sputtering technique. The deposition temperature was raised from 50 to 300℃, and its influence on the film structure and refractive index was investigated. X-ray diffraction analysis shows that the crystalline strucure of the films transforms from the （101） to （002） oriented hexagonal CrzN phase as the increase of substrate tempera- ture above 50℃, and a highly texatred film grows at 100℃. An empirical relation between the crystalline orientation and infrared active modes of the films is obtained, i.e., the Fourier transform infrared （FTIR） spectrum of the film prepared at 50℃ exhibits only A1 （TO） mode. The prominent peak in the FTIR spectra of the film prepared above 50℃is assigned to the E1 （TO） mode and is correlated with the （002） or c-axis oriented hexagonal wurtzite phase of Cr2N. In the surface analysis of atomic force microscopy, a transformation from the featureless surface to columnar-type morphology is observed with the increase of substrate temperature from 50 to 100℃, exhibiting c-axis oriented crystallite growth. A further increase in substrate temperature to 200℃ causes the c-axis crystallites to merge, resulting in the formation of voids. The refractive index （n） of the deposited films is obtained using spectroscopic ellipsometry.
Chromium nitride （Cr2N） thin films were prepared by a DC magnetron sputtering technique. The deposition temperature was raised from 50 to 300℃, and its influence on the film structure and refractive index was investigated. X-ray diffraction analysis shows that the crystalline strucure of the films transforms from the （101） to （002） oriented hexagonal CrzN phase as the increase of substrate tempera- ture above 50℃, and a highly texatred film grows at 100℃. An empirical relation between the crystalline orientation and infrared active modes of the films is obtained, i.e., the Fourier transform infrared （FTIR） spectrum of the film prepared at 50℃ exhibits only A1 （TO） mode. The prominent peak in the FTIR spectra of the film prepared above 50℃is assigned to the E1 （TO） mode and is correlated with the （002） or c-axis oriented hexagonal wurtzite phase of Cr2N. In the surface analysis of atomic force microscopy, a transformation from the featureless surface to columnar-type morphology is observed with the increase of substrate temperature from 50 to 100℃, exhibiting c-axis oriented crystallite growth. A further increase in substrate temperature to 200℃ causes the c-axis crystallites to merge, resulting in the formation of voids. The refractive index （n） of the deposited films is obtained using spectroscopic ellipsometry.
基金
financially supported by the National Institute of Laser and Optronics(NILOP)
