Experimental study of a low-pressure hybrid RF discharge  

作　　者：Elena KRALKINA Polina NEKLIUDOVA Vladimir PAVLOV Konstantin VAVILIN Ilya ZADIRIEV and Chen ZHAO 

机构地区：[1]Physical Electronics Department,Faculty of Physics,Lomonosov Moscow State University,119991 Moscow,Russia

出　　处：《Plasma Science and Technology》2020年第5期70-82,共13页等离子体科学和技术（英文版）

摘　　要：Experimental study of the low-pressure hybrid RF discharge with both inductive and capacitive channels was carried out. The RF power unit consists of inductor(antenna) and capacitor plates connected in parallel to the same RF power source. A separating capacitor Csepis included into the circuit between the antenna ends and the lead connected to the discharge capacitor plate in order to prevent the closing of the capacitive circuit through direct current by inductor and to control the contribution of capacitive channel to discharge sustaining. It is shown that at low power of the RF power source, power coupling to the discharge mainly occurs through the capacitive channel. Increasing the power of the RF power source increases the power coupled in the inductive channel, electron density, and current flowing through the capacitive channel. This leads to increasing voltage drop on the separating capacitor and partial cutoff of the capacitive channel. At separating capacitance values below certain value(below 50 pF in the present experiments), the self-bias of the loaded plate of the discharge capacitor becomes positive indicating that the thickness of the electrode sheath of the loaded electrode decreases compared to thickness of the sheath of the grounded electrode. The thickness of the space-charge sheath of the grounded electrode decreases with increasing power coupled to the plasma. At separating capacitance below 50 pF, higher harmonics of the RF voltage and current are actively generated in the capacitive discharge channel. Increasing the separating capacitance leads to decreasing electron density, increasing effective electron temperature and more effective RF energy coupling to plasma due to increasing relative importance of the capacitive discharge channel.

关 键 词：RADIO-FREQUENCY DISCHARGE PLASMA E-mode H-MODE 

分 类 号：O53[理学—等离子体物理] O461.2[理学—物理]