Transition between different regimes of rf glow discharges.
Transition between different regimes of rf glow discharges.
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DOI：
10.1103/physreva.41.4447
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发表时间：
1990-04
期刊：
影响因子：
--
通讯作者：
Belenguer;Boeuf
中科院分区：
文献类型：
--
作者：
Belenguer;Boeuf
射频辉光放电的自洽流体模型已用于分析两种不同放电方式的存在以及它们之间的过渡。这些政权的存在是由列维茨基（Levitskii）先前建立的。物理。技术。物理。 2, 887 (1958)]。这些政权的自我维持和权力沉积机制截然不同。在第一种状态下，称为“乘波状态”，对应于低放电功率，大部分功率沉积是由于鞘层膨胀加热的体等离子体电子造成的。在对应于较高放电功率的被称为“二次电子状态”的第二状态中，放电主要由电极在离子轰击和鞘层区域中的雪崩作用下发射的电子来维持。数值结果与 Godyak 和 Kanneh 之前的实验测量结果非常吻合 [IEEE Trans.等离子体科学。 PS-14, 112 (1986)]。本文提出的结果构成了对这些不同政权及其之间过渡的第一个自洽的描述。该模型的有效范围仅限于高于一小部分托的压力和低于几十兆赫的频率。考虑的气体是氦气，放电功率在 0 到 700 mW ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$ 之间变化。该模型基于描述带电粒子输运的电子和离子流体方程的解以及电场的泊松方程。通过分别考虑分别代表电子分布函数的尾部和主体的两个电子组，获得了电子动力学的真实描述。通过蒙特卡罗模拟验证了双电子群流体模型的有效性。
A self-consistent fluid model of radio-frequency glow discharges has been used to analyze the existence of two different discharge regimes and the transition between them. The existence of these regimes had been previously established by Levitskii [Sov. Phys. Tech. Phys. 2, 887 (1958)]. The self-sustaining and power-deposition mechanisms that characterize each of these regimes are drastically different. In the first regime, termed as the ``wave-riding regime'' corresponding to low discharge power, most of the power deposition is due to bulk plasma electrons heated by the sheath expansions. In the second regime termed as the ``secondary electron regime'' corresponding to higher discharge power, the discharge is sustained mainly by electrons emitted by the electrodes under ion bombardment and avalanching in the sheath regions. The numerical results are in good agreement with previous experimental measurements by Godyak and Kanneh [IEEE Trans. Plasma Sci. PS-14, 112 (1986)]. The results presented in this paper form the first self-consistent description of these different regimes and of the transition between them. The validity domain of the model is restricted to pressure higher than a fraction of Torr and frequency less than a few tens of MHz. The gas being considered is helium and the discharge power varies between 0 and 700 mW ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$. The model is based on solutions of electron and ion fluid equations describing charged particle transport coupled with Poisson's equation for the electric field. A realistic description of the electron kinetics has been obtained by considering separately two electron groups representing, respectively, the tail and the bulk of the electron distribution function. The validity of the two-electron group fluid model has been checked with Monte Carlo simulations.