双脉冲磁控溅射峰值靶电流密度对TiN薄膜结构与力学性能的影响

Influences of Target Peak Current Density on the Microstructure and Mechanical Properties of TiN Films Deposited by Dual Pulsed Power Magnetron Sputtering

自主研发了双脉冲磁控溅射技术,提出在一个脉冲周期内电流呈阶梯式上升的双脉冲电场设计理念,通过对2个脉冲阶段持续时间和峰值靶电流密度的调配,既满足提高镀料粒子动能与离化率以制备高性能薄膜的工艺要求,又达到增加脉冲持续时间以提高薄膜沉积速率的效能目标。采用双脉冲磁控溅射技术,在后期脉冲阶段的不同峰值靶电流密度下制备4组TiN薄膜,研究了峰值靶电流密度对薄膜微观结构和力学性能的影响。结果表明,将峰值靶电流密度提高至0.87 A/cm^2时,所制备的TiN薄膜呈现出颗粒细小且致密的组织,平均晶粒尺寸为17 nm。同时,薄膜的显微硬度和膜基结合力可分别达29.5 GPa和30.0 N。

The low kinetic energy and low ionization rate of deposited particle of traditional magnetron sputtering led to low density and poor adhesion of TiN film. The peak current density between cathodic target and anodic chamber was increased several times through the adoption of pulsed power supply mode with low duty cycle, which further enhanced kinetic energy and ionization rate of deposited particle.But the average deposition rate of thin film was significantly reduced. Therefore, a design concept of dual pulsed electric field mode was proposed, which allowed to adjust duration time and target peak current density of the dual pulses. It not only enhanced kinetic energy and ionization rate of deposited particle to satisfy the demand of fabrication of high performance film, but also increased the duration time of pulse to achieve high average deposition rate. In the manuscript, TiN films were deposited by dual pulsed power magnetron sputtering with different target peak current densities of the second pulse stage. The microstructure and mechanical properties of TiN films were characterized using XRD, SEM, nanoindentation and microscratch test. It was found that the TiN film deposited under target peak current density of 0.87 A/cm2 exhibited finely dense microstructure with average grain size of 17 nm. Additionally, the hardness and film-substrate adhesion of such film were as high as 29.5 GPa and 30.0 N, respectively.