中国物理B ›› 2018, Vol. 27 ›› Issue (4): 45202-045202.doi: 10.1088/1674-1056/27/4/045202
• PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES • 上一篇 下一篇
Chan Xue(薛婵), Fei Gao(高飞), Yong-Xin Liu(刘永新), Jia Liu(刘佳), You-Nian Wang(王友年)
Chan Xue(薛婵)1, Fei Gao(高飞)1, Yong-Xin Liu(刘永新)1, Jia Liu(刘佳)2, You-Nian Wang(王友年)1
摘要:
A retarding field energy analyzer (RFEA) is used to measure the time-averaged ion energy distributions (IEDs) on the substrate in both continuous wave (CW) and synchronous pulse modulated radio-frequency (RF) inductively coupled Ar plasmas (ICPs). The effects of the phase shift θ between the RF bias voltage and the RF source on the IED is investigated under various discharge conditions. It is found that as θ increases from 0 to π, the IED moves towards the low-energy side, and its energy width becomes narrower. In order to figure out the physical mechanism, the voltage waveforms on the substrate are also measured. The results show that as θ increases from 0 to π, the amplitude of the voltage waveform decreases and, meanwhile, the average sheath potential decreases as well. Specifically, the potential drop in the sheath on the substrate exhibits a maximum value at the same phase (i.e., θ=0) and a minimum value at the opposite phase (i.e., θ=π). Therefore, when ions traverse across the sheath region above the substrate, they obtain less energies at lower sheath potential drop, leading to lower ion energy. Besides, as θ increases from π to 2π, the IEDs and their energy widths change reversely.
中图分类号: (Discharges for spectral sources)