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Analysis of Si Etch Uniformity of Very High Frequency Driven - Capacitively Coupled Ar/SF6 Plasmas  

Lim, Seongjae (Department of Energy Systems Engineering, Seoul National University)
Lee, Ingyu (Department of Energy Systems Engineering, Seoul National University)
Lee, Haneul (Department of Energy Systems Engineering, Seoul National University)
Son, Sung Hyun (Department of Energy Systems Engineering, Seoul National University)
Kim, Gon-Ho (Department of Energy Systems Engineering, Seoul National University)
Publication Information
Journal of the Semiconductor & Display Technology / v.20, no.4, 2021 , pp. 72-77 More about this Journal
Abstract
The radial distribution of etch rate was analyzed using the ion energy flux model in VHF-CCP. In order to exclude the effects of polymer passivation and F radical depletion on the etching. The experiment was performed in Ar/SF6 plasma with an SF6 molar ratio of 80% of operating pressure 10 and 20 mTorr. The radial distribution of Ar/SF6 plasma was diagnosed with RF compensated Langmuir Probe(cLP) and Retarding Field Energy Analyzer(RFEA). The radial distribution of ion energy flux was calculated with Bohm current times the sheath voltage which is determined by the potential difference between the plasma space potential (measured by cLP) and the surface floating potential (by RFEA). To analyze the etch rate uniformity, Si coupon samples were etched under the same condition. The ion energy flux and the etch rate show a close correlation of more than 0.94 of R2 value. It means that the etch rate distribution is explained by the ion energy flux.
Keywords
VHF-CCP; Electronegative plasma; Dry etch; Etch rate; Ion energy flux; Etch uniformity; and Semiconductor manufacturing;
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  • Reference
1 Barbara Abraham-Shrauner and Chungdar Daniel Wang, "Model of etching profiles for ion energy flux dependent etch rates in a collisionless plasma sheath," J. Appl. Phys., Vol. 77 pp. 3445-3449, (1994)   DOI
2 L Lallement, A Rhallabi, C Cardinaud, M C Peignon-Fernandez and L L Alves, "Global model and diagnostic of a low-pressure SF6/Ar inductively coupled plasma," Plasma Sources Sci. Technol. Vol. 18, 025001 (2009)   DOI
3 Shahid Rauf, Kallol Bera and Ken Collins, "Self-consistent simulation of very high frequency capacitively coupled plasmas," Plasma Sources Sci. Technol. Vol. 17, 035003 (2008)   DOI
4 Jiwon Kwon, Sangwon Ryu, Jihoon Park, Haneul Lee, Yunchang Jang, Seolhye Park and Gon Ho Kim, "Development of Virtual Metrology Using Plasma Information Variables to Predict Si Etch Profile Processed by SF6/O2/Ar Capacitively Coupled Plasma," Materials, Vol. 14, 3005 (2021).   DOI
5 Vincent M. Donnelly, and Avinoam Kornblit., "Plasma etching: Yesterday, today, and tomorrow," J. Vac. Sci. Technol. A, Vol. 31, 050825, (2013).   DOI
6 M A Lieberman, J P Booth, P Chabert, J M Rax, and M M Turner., "Standing wave and skin effects in large-area, high frequency capacitive discharges," Plasma Sources Sci. Technol, Vol. 11, pp. 283-293, (2002)   DOI
7 P Chabert., "Electromagnetic effects in high-frequency capacitive discharges used for plasma processing," J. Phys. D: Appl. Phys, Vol. 40 pp. 63-73 (2007)   DOI
8 Banqiu Wu, Ajay Kumar, and Sharma Pamarthy, "High aspect ratio silicon etch: A review," J. Appl. Phys, Vol. 108, 051101 (2010)   DOI
9 Chris G N Lee, Keren J Kanarik and Richard A Gottoscho, "The grand challenges of plasma etching: a manufacturing perspective," J. Phys. D: Allp. Phys, Vol. 47, 273001 (2014)   DOI
10 I G Kouznetsov, A J Lichtenberg, and M A. Lieberman, "Modelling electronegative discharges at low pressure," Plasma Sources Sci. Technol., Vol. 5, pp. 662-676, (1996)   DOI
11 Pascal Chabert and Nicholas Braithwaite, Physics of Radio-Frequency Plasmas, CAMBRIDGE, pp40-41, (2011)
12 Michael A. Lieberman and Allan J. Lichtenberg., Principles of Plasma Discharges and Materials Processing, WILEY, pp. 327-386, 424-494 (2005).
13 Konstantinos P. Giapis, Geoffrey R. Scheller, Richard A. Gottscho, William S. Hobson, and Yong H. Lee, "Microscopic and macroscopic uniformity control in plasma etching.," Appl. Phys. Lett, Vol. 57 pp. 983-985 (1990)   DOI
14 J. Ding, J.S. Jenq, G.H. Kim, L. Maynard, J. S. Hamers, N. Hershkowitz and J. W. Taylor, "Etching rate characterization of SiO2 and Si using ion energy flux and atomic fluorine density in a CF4/O2/Ar electron cyclotron resonance plasma," J. Appl. Sci. Technol. A. Vol. 11, pp 1283-1288 (1993)
15 Yun Chang Jang, Seol Hye Park, Sang Min Jeong, Sang Won Ryu and Gon Ho Kim, "Role of Features in Plasma Information Based Virtual Metrology(PI-VM) for SiO2 Etching Depth," J of the Semiconductor & Display Technology, Vol. 18, pp 30-34 (2019)