基于均匀模型的低气压电容耦合射频放电特性研究  

Modeling and Characterization of Low-Pressure Capacitive Coupled RF Discharge Properties

作　　者：王宇天[1] 张百灵[1] 李益文[1,2] 樊昊[1] 高岭[1] 庄重[1] 

机构地区：[1]空军工程大学等离子体动力学重点实验室,西安710038 [2]西北工业大学航天学院,西安710072

出　　处：《真空科学与技术学报》2016年第7期773-778,共6页Chinese Journal of Vacuum Science and Technology

基　　金：国家自然科学基金(项目11372352;51306207)

摘　　要：针对磁流体流动控制技术对大体积、均匀放电等离子体的需要,开展了低气压下平板型电容耦合放电特性实验研究,并基于均匀射频放电模型,联立能量平衡方程建立诊断模型对等离子体参数进行诊断。结果表明:气压较低时,放电为α模式,整个放电空间发光较为均匀,当气压大于500 Pa时,放电转变为γ模式,在电极附近出现负辉光区,但负辉光区较厚占据了整个放电空间,随着气压增大,负辉光区、法拉第暗区厚度减小,并在放电区域中心出现明显正柱区,正柱区面积随负载功率的增大而增大;放电为γ模式时,电流将随负载功率增大而增大,而电压先不变后增大,并且转折点负载功率随着气压增大而增大;电子数密度ne随负载功率的增大线性增大,而电子温度T_e只是略有增大,约为5500 K(0.47 e V)。The parallel electrode capacitive-coupled RF discharge at low pressures was mathematically described with homogeneous RF discharge model,theoretically calculated with simultaneous energy balance equation and experimentally evaluated,aiming at magnetohydrodynamic flow control of bulk mass and homogeneous plasma.The impact of the pressure,voltage and load-power,on the plasma properties was investigated. The results show that the pressure,voltage and load-power strongly affect the plasma behavior. For example,as the pressure increased,α-discharge mode,at low pressure with a glow uniformly covering the whole region,turned into γ-discharge mode,accompanied by bright glow close to the electrodes,because of 2^（nd） electron excitation. In γ-mode,as the e-density ne increased,the e-temperature Tefirst decreased rapidly and then slowly; and as the load-power increased,both the current and e-density nelinearly increased,while e-temperature T_e slightly increased at a decreasing rate; and the voltage increased only at a large load-power.

关 键 词：电容耦合射频放电 等离子体诊断 均匀模型 电子数密度 电子温度 

分 类 号：O531[理学—等离子体物理]