论文标题
高压鞘调制和较高的低压谐波产生非常高频率的电容性等离子体，锯齿波形激发了
High frequency sheath modulation and higher harmonic generation in a low pressure very high frequency capacitively coupled plasma excited by sawtooth waveform
论文作者
论文摘要
进行了粒子中的模拟研究，以调查低压下的排放不对称性，较高的谐波代和电子加热机制，非常高的频率电容性等离子体（CCP）像电流波形一样激发。选择两个当前密度为50 A/M2和100 A/M2，用于在氩等离子度中的恒定气压为5 mTORR。驾驶频率从13.56 MHz到54.24 MHz。在较低的驾驶频率下，观察到接地电极处瞬时鞘缘位置的高频调制。这些高频振荡产生了多个电离光束，就像靠近鞘缘的结构一样，在放电中驱动等离子密度并负责在较低驱动频率下排放/电离不对称。相反，电极电压在较高的驱动频率下显示出更高的谐波产生，并且在散装等离子体中观察到相应的电场瞬变。在较低的驾驶频率下，电子加热最大接近鞘缘，然后在等离子体散装内进行电子冷却，但是，在较高的驱动频率下获得了替代加热和冷却，即像爆裂的结构一样。这些结果表明，这些放电中的电子加热将无法通过简单的分析模型准确地描述。
A particle-in-cell (PIC) simulation study is performed to investigate the discharge asymmetry, higher harmonic generations and electron heating mechanism in a low pressure very high frequency capacitively coupled plasma (CCP) excited by a saw-tooth like current waveform. Two current densities, 50 A/m2 and 100 A/m2 are chosen for a constant gas pressure of 5 mTorr in argon plasma. The driving frequency is varied from 13.56 MHz to 54.24 MHz. At a lower driving frequency, high frequency modulations on the instantaneous sheath edge position at the grounded electrode are observed. These high frequency oscillations create multiple ionization beam like structures near to the sheath edge that drives the plasma density in the discharge and responsible for discharge/ionization asymmetry at lower driving frequency. Conversely, the electrode voltage shows higher harmonics generation at higher driving frequencies and corresponding electric field transients are observed into the bulk plasma. At lower driving frequency, the electron heating is maximum near to the sheath edge followed by electron cooling within plasma bulk, however, alternate heating and cooling i.e. burst like structures are obtained at higher driving frequencies. These results suggest that electron heating in these discharges will not be described accurately by simple analytical models.
