Plasma process modulation from polymerization to etching in C4F8/Ar plasma by nitrogen gas addition

POSTER

Abstract

additionLow-pressure C4F8 based plasmas are widely used in semiconductor fabrication such as deposition or etching with various gas mixtures [1,2]. Although, oxygen gas has been widely used in C4F8 plasmas to control the depositing layer thickness, it is reported the oxygen atoms could deteriorate polymer-based surfaces during processes [3]. Therefore, in this work, the effects of nitrogen addition to C4F8/Ar plasmas was studied to modulate deposition process without severe surface damages. From the results, by nitrogen gas addition, it was found that the thickness of the deposited layer on the Si substrate was dramatically reduced from 194.3 nm to 3.4 nm and the cross-sectional views of the Si substrate clearly indicated that the plasma process was switched from polymerization to etching. By means of plasma spectroscopy and surface analyses, we can conclude the nitrogen atoms in plasma could scavenge fluorocarbon molecules involved in polymer deposition through the formation of CN molecule and release of F atoms [4].

[1] D. M. Chen, L. S. Engelmann, R. L. Bruce, E. A. J. Gottlieb, S. Oehrlein, Fluorocarbon assisted atomic layer etching of SiO2 and Si using cyclic Ar/C4F8 and Ar/CHF3 plasma, J. Vac. Sci. Technol. A, 34 (2016) 01B101, doi: 10.1116/1.4935462.

[2] I. Chun, A. Efremov, G. Y. Yeom, K. Kwon, A comparative study of CF4/O2/Ar and C4F8/O2/Ar plasmas for dry etching applications, Thin solid films, 579 (2015) 136-143. https://doi.org/10.1016/j.tsf.2015.02.060.

[3] Y. S. Mor, T. C. Chang, P. T. Liu, T. M. Tsai, C. W. Chen, S. T. Yan, C. J. Chu, W. F. Wu, F. M. Pan, W. Lur, S. M. Sze. Effective repair to ultra-low-k dielectric material (k2.0) by hexamethyldisilazane treatment, J. Vac. Sci. Technol. B, 20 (2002) 1334-1338, doi: 10.1116/1.1488645.

[4] C. Tsai, D. L. McFadden, Gas-phase atom—radical kinetics of N and O atom reactions with CF and CF2 radicals, Chem. Phys. Lett, 173 (1990) 241-245, https://doi.org/10.1016/0009-2614(90)80086-S.

*This work was supported by a National Research Facilities and Equipment Center grant funded by the Ministry of Education (2021R1A6C101B383), by the R&D program of “Plasma Equipment Intelligence Convergence Research Center (No. 1711121944)” through the National Research Council of Science & Technology grant provided by the Korean government and also partly supported by SEMES.

Publication: Elsvier 'Vacuum' : under revision

Presenters

  • Woojin Park

    • Department of Applied Plasma and Quantum beam Engineering, Jeonbuk national university
    • 1Department of Applied Plasma and Quantum Beam Engineering, Jeonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, 54896, Republic of Korea 2Depa

Authors

  • Woojin Park

    • Department of Applied Plasma and Quantum beam Engineering, Jeonbuk national university
    • 1Department of Applied Plasma and Quantum Beam Engineering, Jeonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, 54896, Republic of Korea 2Depa

  • Se Youn Moon

    • Department of Applied Plasma and Quantum beam Engineering, Jeonbuk national university
    • 1Department of Applied Plasma and Quantum Beam Engineering, Jeonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, 54896, Republic of Korea 2Depa

  • Jonggu Han

    • 1Department of Applied Plasma and Quantum Beam Engineering, Jeonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, 54896, Republic of Korea 2Depa

  • Solee Park

    • 1Department of Applied Plasma and Quantum Beam Engineering, Jeonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do, 54896, Republic of Korea 2Depa