THE INFLUENCE OF SPUTTERING BIAS-VOLTAGE ON LaB₆ FILM'S CHARACTERISTICS

The deposition of lanthanum boride (LaB₆) thin films by the d.c. magnetron sputtering were studied. XRD, AFM and Stylus Profiler were used to characterize the properties of the deposited films. The XRD was used to study the crystallinity. The results of the XRD showed that the dominant crystal face is (100) face. The crystallinity decreased with the increased bias-voltage value, but the influence of bias-voltage on the films is different on different crystal face. The intensity (100) face was influenced by the bias-voltage more obviously than other faces except the influence of thickness. The diffraction peak maximal intensity of (100) face changed from 1256(on 0V) to 580(on -150V), but the intensity of (110) face changed from 614(on 0V) to 486(on -150V). The rel. int(100%) of (110) face changed from 38.70 to 74.52. The deposition rate decreased with the increased bias-voltage value, but the decreased was not obviously. The maximum and minimum of the deposition ratio were 17.53nm and 13.75nm respectively. Surface morphology of the films was studied by the AFM. The crystallite of the films was less than 50nm. The maximal roughness of the films decreased firstly and increased afterward, and it got the maximum on the -50V bias-voltage.