Durocher-Jean A, Stafford L, Dap S, Makasheva K, Clergereaux R
Département de Physique, Université de Montréal, Montréal, Québec, Canada H3C 3J7.
Université de Toulouse; UPS, INPT; LAPLACE, 118 route de Narbonne, 31062 Toulouse Cedex 9, France and CNRS; LAPLACE; 31062 Toulouse, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2014 Sep;90(3):033106. doi: 10.1103/PhysRevE.90.033106. Epub 2014 Sep 11.
Microwave plasmas excited at electron-cyclotron resonance were studied in the 0.5-15 mTorr pressure range. In contrast with low-limit pressure conditions where the plasma emission highlights a fairly homogeneous spatial structure, a periodic spatial modulation (period ∼6.2 cm) appeared as pressure increased. This feature is ascribed to a local power deposition (related to the electron density) due to the presence of a standing electromagnetic wave created by the feed electromagnetic field (2.45 GHz) in the cavity formed by the reactor walls. Analysis of the electron energy probability function by Langmuir probe and optical emission spectroscopy further revealed the presence of a high-energy tail that showed strong periodic spatial modulation at higher pressure. The spatial evolution of the electron density and of the characteristic temperature of these high-energy electrons coincides with the nodes (maximum) and antinodes (minimum) of the standing wave. These spatially-modulated power deposition and electron heating mechanisms are then discussed.
研究了在0.5 - 15毫托压力范围内电子回旋共振激发的微波等离子体。与低限压力条件下等离子体发射呈现相当均匀的空间结构不同，随着压力增加出现了周期性空间调制（周期约为6.2厘米）。该特征归因于由反应器壁形成的腔内馈入电磁场（2.45吉赫兹）产生的驻波导致的局部功率沉积（与电子密度有关）。通过朗缪尔探针和光发射光谱对电子能量概率函数的分析进一步揭示，在较高压力下存在一个高能尾部，其表现出强烈的周期性空间调制。这些高能电子的电子密度和特征温度的空间演化与驻波的节点（最大值）和波腹（最小值）一致。然后讨论了这些空间调制的功率沉积和电子加热机制。
