摘要
为了提高容性耦合射频放电所产生的等离子体密度,在射频放电中利用空心电极结构替代平板电极,实验研究射频空心电极放电的等离子体特性。利用Langmuir探针诊断了电极间距、孔径和孔深对等离子体电子数密度的影响,并且对不同放电参数下空心电极上的自偏压进行了比较。实验结果表明:当空心电极孔径d=20 mm、电极间距L=3 cm、孔深h=3 mm、气压p为50~300 Pa时,在孔外获得的等离子体电子数密度最高,约为10^17~10^18m^-3。同时实验测得不同放电参数下射频空心电极上的自偏压也完全与鞘电压分布的"面积比"规律相符,即小电极处的鞘电压更高。射频振荡加热和空心阴极效应相互耦合能够产生稳定性好、电离率高、密度高的等离子体,电极几何参数和自偏压对获得高密度等离子体有着重要的影响。
In order to improve the plasma density, hollow electrode is used to replace plate electrode in capacitive coupled radio frequency(RF) discharge. The plasma characteristics of this RF hollow electrode discharge are studied experimentally. Langmuir probe was used to diagnose the effects of electrode gap, hole diameter and hole depth on plasma electron density. The self-bias voltages under different discharge parameters were compared. The results show that, when the hole diameter d equals 20 mm, the electrode gap L equals 3 cm, the hole depth h equals 3 mm, and p is in the range of 50~300 Pa, the plasma electron density obtained outside the hole is the highest, about 10^17~10^18 m^-3. At the same time, the self-bias voltage about the hollow electrode is also completely consistent with the ‘area ratio’ rule of sheath voltage distribution under different discharge parameters, the sheath voltage at the small electrode area is higher. The coupling of RF oscillating heating and hollow cathode effect can produce plasma with good stability, high ionization rate, and high density. Geometric parameters and self-bias voltage have important influences on obtaining high density plasma.
作者
白志丽
何锋
李佩贞
贺柳良
缪劲松
欧阳吉庭
BAI Zhili;HE Feng;LI Peizhen;HE Liuliang;MIAO Jinsong;OUYANG Jiting(School of Physics,Beijing Institute of Technology,Beijing 100081,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2020年第11期4069-4076,共8页
High Voltage Engineering
基金
国家自然科学基金(11475019)。
关键词
容性耦合射频放电
空心电极
放电参数
电子密度
自偏压
radio frequency capacitive coupled plasma
hollow electrode
discharge parameter
electron density
self-bias voltage
