含氢四面体非晶碳膜的制备与结构及力学性能

Preparation,Microstructure and Mechanical Properties of Hydrogenated Tetrahedral Amorphous Carbon Films

采用化学气相沉积法制备具有优异力学性能的含氢四面体非晶碳膜有望满足工业应用的要求。通过自主设计的等离子体增强化学气相沉积实验系统制备含氢四面体非晶碳膜,并对其微观结构与力学性能进行研究。随着偏压从-200 V增加到-500 V,薄膜硬度和弹性模量先增加后减少,最大达到34.0 GPa和282.0 GPa。压应力随着偏压的变化表现出相同的变化趋势。与传统等离子体增强化学气相沉积方法相比,自主设计的等离子体增强化学气相沉积系统制备的碳膜硬度和弹性模量明显提升,碳膜sp3含量(摩尔分数)超过62.3%,制备出的碳膜具有典型的含氢四面体非晶碳膜特征,而非含氢碳膜,主要是由于水冷射频双螺旋电极与平板电极结合增强了粒子的轰击和离化率,提高了薄膜sp3含量。这为在工业中应用制备高硬度和弹性模量的含氢四面体非晶碳膜提供了可能。

Preparation of hydrogenated tetrahedral amorphous carbon(ta-C:H)films with good mechanical properties by plasma-enhanced chemical vapor deposition(PECVD)is expected to meet requirement in industrial application.This paper reported the microstructure and mechanical properties of(ta-C:H)films prepared by a self-designed PECVD technique.As the bias voltage varies from-200 V to-500 V,the hardness and elastic modulus first decrease and then increase,reaching the maximum values of 34.0 GPa and 282.0 GPa respectively.The evolution of compressive stress with bias voltage shows a similar trend.In this case,the hardness and elastic modulus of films prepared by the self-designed PECVD technique both are improved,compared with those by the conventional PECVD methods.The mole fraction of sp3 hybridized bond is greater than 62.3%when the bias voltage changes from-200 V to-500 V.Carbon films were deposited using the self-designed PECVD technique,showing the typical characteristics of ta-C:H films.This can be attributed to the increased ion bombardment and ionization due to the incorporation of a water-cooled radio frequency double helix electrode and a plate electrode resulting in an enhanced sp3 content.This paper provides a promising technology to fabricate ta-C:H films with high hardness and elastic modulus for industrial applications.