AVS 66th International Symposium & Exhibition
    Plasma Science and Technology Division Tuesday Sessions
       Session PS-TuP

Paper PS-TuP21
Simulation Study of Capacitively Coupled Radio Frequency Silane/Hydrogen Plasma Discharges - Effect of Tailored Voltage Waveforms

Tuesday, October 22, 2019, 6:30 pm, Room Union Station B

Session: Plasma Science and Technology Poster Session
Presenter: Keh-Chyang Leou, National Tsing Hua University, Taiwan, Republic of China
Authors: S.W. Huang, National Tsing Hua University, Taiwan, Republic of China
K.C. Leou, National Tsing Hua University, Taiwan, Republic of China
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Capacitively coupled plasma discharges (CCP) have been widely employed for material processing, such as etching and deposition. The purpose of this study is to investigate the effect of tailored voltage waveforms (TVWs) on the plasma characteristics of SiH4/H2 plasmas, typically, for Si film deposition. A fluid model based numerical simulation analysis (CFD-ACE+) is employed to investigate the basic discharge characteristics and corresponding basic physical and chemical mechanisms occurring in the plasma reactor. The TVWs adopted in this study are formed by four harmonics of 13.56 MHz sinusoidal voltages. Different voltage waveforms can be generated by tuning the relative phase between the four frequencies. A peak or valley voltage waveform is obtained when the "phase" is 0 or π, respectively. Simulation results show that the “peak” waveform results in a lower sheath voltage, and the SiH2/SiH3 flux ratio reaching the substrate is 40% lower than that for CCP with single frequency of 13.56 MHz. Thus, by using TVWs, it is possible to fine tune the structure and/or property of the deposited Si film. The detailed results of the simulation analysis of CCPs with TVWs will be presented.

*Acknowledgement : Work supported by the MOST, Taiwan/ROC.