磁控溅射制备CrN_x薄膜及其结构和性能研究

THE STRUCTURAL AND MECHANICAL PROPERTIES OF CrN_x THIN FILMS PREPARED BY REACTIVE MAGNETRON SPUTTERING

采用反应磁控溅射技术制备了CrNx薄膜,并研究了氮气分压对CrNx薄膜的沉积速率、结构和摩擦系数的影响。研究发现:采用反应磁控溅射技术能有效地抑制靶中毒现象,薄膜的沉积速率变化仅仅是由于氩和氮对靶的溅射产率不同造成的。通过调节不同的氮分压,可将CrNx薄膜的结构在很大的范围内调控,从Cr到Cr2N,到无定形,一直到CrN多种结晶形态的变化。且制备出的CrNx薄膜晶粒细小致密,晶粒和粒径分布都很均匀,晶粒在几十纳米左右。CrN薄膜的摩擦系数在0.70左右,无定形态CrNx和Cr2N的摩擦系数相对比较小,在0.20￣0.30之间;Cr薄膜与钢球和氮化硅球对磨的摩擦系数相差比较大,分别为0.55和0.72。

CrNx films were prepared using reactive magnetron sputtering in order to analyze the structural and mechanical features regarding to Na partial pressure variations. XRD diffraction patterns revealed that only Cr phase with strong （111） orientation was observed for 0% nitrogen partial pressure, the mixed Cr, N and Cr phase appeared at 20% nitrogen partial pressure, while for 40% N2 partial pressure no crystal structure feature was seen. Further increasing the nitrogen partial pressure to 60% or above, only CrN phase appeared. SEM results showed a columnar-type structure lying in the transition zone between T and I zones of Thornton Model for the films. The Cr film （0% Nz partial pressure） showed a low friction coefficient against the steel ball, but much higher against the Si3N4 ball. The friction coefficient of the CrNx films is low in the range of nitrogen partial pressure from 20% and 40%, and then reached about 0.70. The obviously changes was not observed with the N2 partial pressure further increasing.