MW-ECR PE-UMS等离子体特性及对Zr-N薄膜结构性能的影响

Zr-N films prepared by MW-ECR PE-UNB alanced magnetron sputtering:plasma diagnostics and structure evolution

采用静电探针技术对微波电子回旋共振(MW ECR)等离子体进行了诊断,利用等离子体增强非平衡磁控溅射(PE UMS)法在常温下制备了Zr N薄膜,通过EPMA,XRD,显微硬度对膜的结构和性能进行评价.实验结果表明,随氮气流量增加,总的等离子体密度从8.07×109cm-3增加到8.31×109cm-3然后逐渐减小为7.52×109cm-3;而N2+密度则从3.12×108cm-3线性递增到3.35×109cm-3;电子温度变化不大.对薄膜而言,随N2+密度增大,样品中氮含量增加,而晶粒逐渐变小,当样品中N Zr原子比达到1.4时,薄膜中出现亚稳态的Zr3N4相以及非晶相,在更高氮流量下,整个薄膜转变为非晶态.与此相应,薄膜硬度由最初的22.5GPa增大到26.78GPa然后逐渐减小到19.82GPa.

ZrN films were prepared using microwave electron cyclotron resonance (MW-ECR) plasma enhanced unbalanced magnetron sputtering (PE-UMS) technique. The plasma characteristics near the holder were diagnosed by Langmuir probe for various deposition conditions and the films obtained were characterized by electron probe microanalysis x-ray diffraction and micro-hardness. As the N-2 flow rate increases from 2 to 20sccm, the ion density initially increases from 8.07 x 10(9) to 8.31 x 10(9)cm(-3) and then decreases to 7.52 x 10(9)cm(-3), while the N-2(+) ion density increases monotonically from 3.12 x 10(8) to 3.35 x 10(9)cm(-3) and the electron temperature does not vary much. The N concentration in the films increases and the grain size decreases as the N-2(+) ion density increases. And the films become more and more amorphous as the N/Zr ratio is above 1.4. The corresponding microhardness of the deposited films increases from 22.5GPa to the maximum of 26.78GPa, and then decreases linearly to 19.82GPa as the N-2 flow rate increases from 8 to 14sccm. The mechanism of the influence of the plasma characteristics on the microstructure and mechanical properties of the deposited films were discussed.