Detection of Negative Ions in a Helium-Silane RF Plasma
Detection of Negative Ions in a Helium-Silane RF Plasma
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氦硅烷射频等离子体中负离子的检测
DOI：
10.1143/jjap.31.l1791
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发表时间：
1992
影响因子：
1.5
通讯作者：
Yukio Watanabe Yukio Watanabe
中科院分区：
文献类型：
--
作者：
M. Shiratani;T. Fukuzawa;Kenji Eto Kenji Eto;Yukio Watanabe Yukio Watanabe
为了探测氦-硅烷射频等离子体中的负离子，通过方波幅度调制射频放电电压，观察了电子和离子密度的时间演化。分别用微波干涉仪和朗缪尔探头的离子饱和电流计算了电子和离子的密度。实验表明，即使低浓度的硅烷也能在等离子体中形成负离子，其密度估计约为109 cm-3，与电子密度相当。由于结合而形成负离子的电子能量估计在8.9 eV以下，即低于解离电子与SiH4结合的共振峰能量。
In order to detect negative ions in a helium-silane rf plasma, temporal evolutions of the densities of electrons and ions are observed by square-wave-amplitude modulation of an rf discharge voltage. Densities of electrons and ions are deduced using a microwave interferometer and ion saturation current of a Langmuir probe, respectively. The experiments show that negative ions are formed in the plasma even for a low concentration of 0.5% silane and their density is estimated to be about 109 cm-3 which is comparable to the electron density. The energy of electrons which form negative ions due to attachment is estimated to be below 8.9 eV, that is, below the resonance peak energy of dissociative electron attachment to SiH4.