A self-consistent particle-in-cell simulation study is performed to investigate the effect of driving frequency on the electric field non-linearity, electron heating mechanism and electron energy distribution function (EEDF) in a low pressure symmetric capacitively coupled plasma (CCP) discharge at a constant electron plasma frequency. The driving frequency is varied from 27.12 MHz to 100 MHz for a discharge gap of 3.2 cm in argon at a gas pressure of 1 Pa. The simulation results provide insight of higher harmonic generations in a CCP system for a constant electron response time. The spatio-temporal evolution and spatial time averaged electron heating is presented for different driving frequencies. The simulation results predict that the electric field non-linearity increases with a rise in driving frequency along with a concurrent increase in higher harmonic contents. In addition to the electron heating and cooling near to the sheath edge a positive is observed in to the bulk plasma at higher driving frequencies. The EEDF illustrate enhancement in the population of mid-energy range electrons as driving frequency increases thereby changing the shape of EEDF from bi-Maxwellian to nearly Maxwellian. For the constant ion flux on the electrode surface, a decrease in the ion energy by more than half is observed with an increase in driving frequency.

中文翻译：

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恒定电子等离子体频率下甚高频电容放电中的电场非线性

进行了自洽的细胞内粒子模拟研究，以研究驱动频率对低压对称电容耦合等离子体 (CCP) 中的电场非线性、电子加热机制和电子能量分布函数 (EEDF) 的影响以恒定的电子等离子体频率放电。驱动频率从 27.12 MHz 到 100 MHz 不等，放电间隙为 3.2 cm 的氩气和 1 Pa 的气压。模拟结果提供了 CCP 系统中高次谐波生成的洞察力，以获得恒定的电子响应时间。呈现了不同驱动频率的时空演化和空间时间平均电子加热。仿真结果预测电场非线性随着驱动频率的增加以及高次谐波含量的同时增加而增加。除了靠近鞘层边缘的电子加热和冷却之外，在更高的驱动频率下，在体等离子体中观察到正值。EEDF 说明随着驱动频率的增加，中等能量范围电子的数量增加，从而将 EEDF 的形状从双麦克斯韦形变为接近麦克斯韦形。对于电极表面上恒定的离子通量，随着驱动频率的增加，观察到离子能量减少了一半以上。EEDF 说明随着驱动频率的增加，中等能量范围电子的数量增加，从而将 EEDF 的形状从双麦克斯韦形变为接近麦克斯韦形。对于电极表面上恒定的离子通量，随着驱动频率的增加，观察到离子能量减少了一半以上。EEDF 说明随着驱动频率的增加，中等能量范围电子的数量增加，从而将 EEDF 的形状从双麦克斯韦形变为接近麦克斯韦形。对于电极表面的恒定离子通量，随着驱动频率的增加，观察到离子能量减少了一半以上。