N_2-Ar射频放电表面氮化的等离子体特性模拟

N_2-Ar rf discharge surface nitriding plasma characteristics simulation

N2-Ar射频放电等离子体广泛应用于微电子工业的刻蚀、氮化物薄膜的制备及金属表面氮化等技术领域。开发了N2-Ar混合气体容性耦合射频放电PIC/MC自洽模型,模型主要描述了e-,N2+,N+,Ar+等主要带电粒子的行为分布。等离子体的碰撞过程分别考虑了带电粒子(e-,N2+,N+,Ar+)与基态中性N2分子和Ar原子的21种碰撞反应过程。模拟结果表明,在纯N2及N2-Ar混合气体容性耦合射频放电中,各种带电粒子的数密度都在等离子体区达到最大值,且氮分子离子为主要粒子;在N2容性耦合射频放电中,加入10%氩气时,N+平均能量有所增加,在射频电极处两种氮离子(N2+,N+)高能粒子所占比例增加。本研究对认识N2-Ar射频放电等离子体过程微观机理具重要意义。

N2-Ar rf discharge plasma is used in numerous widespread applications, such as the etching in microelectronics industry, the preparation of nitrides film and the metal surface nitriding and so on. A PIC/MC model for the N2-Ar mixture gas capacitively coupled rf discharge processes was developed, in which we describe the behaviour of the main charged particles（e-, N2＋, N＋, Ar＋）and take into account 21 kinds of collisions of charged particles（e-, N2＋, N＋, Ar＋）with ground-state neutral N2 and Ar. It tumed out that however in the N2-Ar mixture gas discharge or N2 gas discharge, the density of charged particles all has the maximum in the plasma region, especially, N2＋ i＋ the main particle. In the N2 gas capacitively coupled rf discharge, with the adding of 10% Ar, the mean energy of N＋ is increasing, and the high-energy proportion of the two particles （N2＋, N＋） in the rf electrode are both increasing. So it was important for us to know the microscopic mechanism of N2-Ar rf discharge.