高功率脉冲磁控溅射的阶段性放电特征

本文从放电靶电流出发,采用一种新的研究方法,即将靶电流分解为多个代表具体放电特性的特征参数,全面而系统的研究了不同的工作气压条件下,靶电流各特征参数随靶电压的增加而进行的演化.结果发现高功率脉冲磁控溅射技术(HPPMS)放电靶电流在靶电压由低向高增加的过程中,出现靶电流峰值和平台值的交替变化,体现出明显的阶段性放电特征,且不同的放电阶段在不同气压下出现一定的移动,会在测量范围内出现某些放电阶段的缺失.本文还通过等离子体发射光谱对HPPMS放电靶前等离子体测量发现五个不同的放电阶段分别主要对应氩原子、铬原子、氩离子、铬离子和氩、铬高价离子的放电,但不同的放电条件下相邻的阶段会出现一定程度的交叠.

Phasic discharge characteristics in high p ower pulsed magnetron sputtering

As one of the burgeoning physical vapor deposition (PVD) techniques, high power pulsed magnetron sputtering (HPPMS), which boasts high ionization rates of sputtered materials and does not suffer from macro-particles, has been investigated extensively recently. Herein, a new method to break down the discharge current into different characteristic components is employed to study the changes of the various parameters as the target voltage is increased at different pressure. Results show a phasic HPPMS discharge when the target voltage is increased, exhibiting an alternate rise of the peak and the platform of the target current. A small change at the discharge stage is observed with increasing pressure, and some stages are missing in some instances. Five discharge stages are found to correspond to the discharge of Ar atoms, Cr atoms, Ar ions, Cr ions, as well as multiply-charged Ar and Cr ions, respectively, according to the optical emission spectra obtained from the HPPMS discharge plasma. Adjacent discharge stages are also found to overlap under certain discharge conditions.
Keywords：high power pulsed magnetron sputteringdischarge target currentgas pressurephasic discharge