磁控溅射辉光放电特性的模拟研究

Computer simulation of the glow discharge characteristics in magnetron sputtering

采用二维、自洽的PIC/MCC(particle-in-cell with Monte Carlo collision)方法,模拟了磁控溅射辉光放电过程,重点讨论了工作参数对放电模式和放电电流的影响.模拟结果表明,当工作气压由小到大或空间磁场从强到弱变化时,放电模式会从阴极空间电荷主导的放电模式过渡到阳极空间电荷主导的放电模式.在过渡状态,对应的工作气压与磁通密度分别为0.67 Pa和0.05 T;随着工作气压的增大,放电电流先增大后趋向平衡,当工作气压超过2.5 Pa时,电流开始随工作气压的增大而减小;而阴极电压增大时,放电电流近似线性增加.

In this paper, the process of glow discharge in magnetron sputtering is studied by the particle-in-cell with Monte Carlo collision method. The proposed model is a two-dimensional and self-consistent approach. The results show that the discharge mode transits from the negative space-charge-dominated mode to positive space-charge-dominated mode with working pressure increasing or magnetic field weakening. At the transition state, working pressure and magnetic field are 0.67 Pa and 0.05 T, respectively. Discharge current increases as the cathode voltage increases. When pressure increases, discharge current first increases and then tends to balance. When the pressure is higher than 2.5 Pa, current begins to decreases with the increase of the pressure.