Yaojun Xiang, Xiao-Kun Wang, Yongxin Liu, Younian Wang
{"title":"负直流偏压对在不同射频电压和气体压力下运行的电容耦合氩等离子体的影响","authors":"Yaojun Xiang, Xiao-Kun Wang, Yongxin Liu, Younian Wang","doi":"10.1088/2058-6272/ad1875","DOIUrl":null,"url":null,"abstract":"\n Effect of a negative direct current (DC) bias,|Vdc|, on the electrical parameters and discharge mode is investigated experimentally in a radio frequency (RF) capacitively coupled Ar plasma operated at different RF voltage amplitudes and different gas pressures. The electron density is measured by using a hairpin probe and the spatio-temporal distribution of electron-impact excitation rate is determined by phase-resolved optical emission spectroscopy, and the electrical parameters are obtained based on the waveforms of the electrode voltage and the plasma current measured by a voltage and current probe. It was found that at a low |Vdc|, i.e., in α mode, the electron density and the RF current decline with increasing |Vdc|, and meanwhile, the plasma impedance becomes more capacitive, due to a widened sheath. So, the RF power deposition is suppressed. When |Vdc| exceeds a certain value, the plasma turns into α-γ hybrid mode (or the discharge becomes dominated by the γ-mode), manifesting a drastically-growing electron density and a moderately-increasing RF current. Meanwhile, the plasma impedance becomes more resistive, so the RF power deposition is enhanced with |Vdc|. Besides, we found that the electrical parameters show similar dependence on |Vdc| at different RF voltages, and the α-γ mode transition occurs at a lower |Vdc| at a higher RF voltage. By increasing the pressure, the plasma impedance becomes more resistive, so the RF power deposition and the electron density are enhanced. Especially, the α-γ mode transition tends to occur at a lower |Vdc| with the increase of the pressure.","PeriodicalId":20250,"journal":{"name":"Plasma Science & Technology","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of a negative DC bias on a capacitively coupled Ar plasma operated at different radio frequency voltages and gas pressures\",\"authors\":\"Yaojun Xiang, Xiao-Kun Wang, Yongxin Liu, Younian Wang\",\"doi\":\"10.1088/2058-6272/ad1875\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"\\n Effect of a negative direct current (DC) bias,|Vdc|, on the electrical parameters and discharge mode is investigated experimentally in a radio frequency (RF) capacitively coupled Ar plasma operated at different RF voltage amplitudes and different gas pressures. The electron density is measured by using a hairpin probe and the spatio-temporal distribution of electron-impact excitation rate is determined by phase-resolved optical emission spectroscopy, and the electrical parameters are obtained based on the waveforms of the electrode voltage and the plasma current measured by a voltage and current probe. It was found that at a low |Vdc|, i.e., in α mode, the electron density and the RF current decline with increasing |Vdc|, and meanwhile, the plasma impedance becomes more capacitive, due to a widened sheath. So, the RF power deposition is suppressed. When |Vdc| exceeds a certain value, the plasma turns into α-γ hybrid mode (or the discharge becomes dominated by the γ-mode), manifesting a drastically-growing electron density and a moderately-increasing RF current. Meanwhile, the plasma impedance becomes more resistive, so the RF power deposition is enhanced with |Vdc|. Besides, we found that the electrical parameters show similar dependence on |Vdc| at different RF voltages, and the α-γ mode transition occurs at a lower |Vdc| at a higher RF voltage. By increasing the pressure, the plasma impedance becomes more resistive, so the RF power deposition and the electron density are enhanced. Especially, the α-γ mode transition tends to occur at a lower |Vdc| with the increase of the pressure.\",\"PeriodicalId\":20250,\"journal\":{\"name\":\"Plasma Science & Technology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.6000,\"publicationDate\":\"2023-12-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Plasma Science & Technology\",\"FirstCategoryId\":\"1089\",\"ListUrlMain\":\"https://doi.org/10.1088/2058-6272/ad1875\",\"RegionNum\":3,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"PHYSICS, FLUIDS & PLASMAS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plasma Science & Technology","FirstCategoryId":"1089","ListUrlMain":"https://doi.org/10.1088/2058-6272/ad1875","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, FLUIDS & PLASMAS","Score":null,"Total":0}
Effect of a negative DC bias on a capacitively coupled Ar plasma operated at different radio frequency voltages and gas pressures
Effect of a negative direct current (DC) bias,|Vdc|, on the electrical parameters and discharge mode is investigated experimentally in a radio frequency (RF) capacitively coupled Ar plasma operated at different RF voltage amplitudes and different gas pressures. The electron density is measured by using a hairpin probe and the spatio-temporal distribution of electron-impact excitation rate is determined by phase-resolved optical emission spectroscopy, and the electrical parameters are obtained based on the waveforms of the electrode voltage and the plasma current measured by a voltage and current probe. It was found that at a low |Vdc|, i.e., in α mode, the electron density and the RF current decline with increasing |Vdc|, and meanwhile, the plasma impedance becomes more capacitive, due to a widened sheath. So, the RF power deposition is suppressed. When |Vdc| exceeds a certain value, the plasma turns into α-γ hybrid mode (or the discharge becomes dominated by the γ-mode), manifesting a drastically-growing electron density and a moderately-increasing RF current. Meanwhile, the plasma impedance becomes more resistive, so the RF power deposition is enhanced with |Vdc|. Besides, we found that the electrical parameters show similar dependence on |Vdc| at different RF voltages, and the α-γ mode transition occurs at a lower |Vdc| at a higher RF voltage. By increasing the pressure, the plasma impedance becomes more resistive, so the RF power deposition and the electron density are enhanced. Especially, the α-γ mode transition tends to occur at a lower |Vdc| with the increase of the pressure.
期刊介绍:
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A Publication of the Institute of Plasma Physics, Chinese Academy of Sciences and the Chinese Society of Theoretical and Applied Mechanics.