Analysis of Variables Effects in 300mm PECVD Chamber Cleaning Process Using NF3

  • Sang-Min Lee (Department of Industrial and Management Engineering, Myongji University) ;
  • Hee-Chan Lee (Department of Electronics Engineering, Myongji University) ;
  • Soon-Oh Kwon (Department of Environmental Engineering and Energy, Myongji University) ;
  • Hyo-Jong Song (Department of Environmental Engineering and Energy, Myongji University)
  • Received : 2024.06.06
  • Accepted : 2024.06.21
  • Published : 2024.06.30

Abstract

NF3, Chamber cleaning gas, has a high Global Warming Potential (GWP) of 17,000, causing significant greenhouse effects. Reducing gas usage during the cleaning process is crucial while increasing the cleaning Rate and reducing cleaning standard deviation (Stdev). In a previous study with a 6-inch PECVD chamber, a multiple linear regression analysis showed that Power and Pressure had no significant effect on the cleaning Rate because of their P-values of 0.42 and 0.68. The weight for Flow is 11.55, and the weights for Power and Pressure are 1.4 and 0.7. Due to the limitations of the research equipment, which differed from those used in actual industrial settings, it was challenging to assess the effects in actual industrial environment. Therefore, to show an actual industrial environment, we conducted the cleaning process on a 12-inch PECVD chamber, which is production-level equipment, and quantitatively analyzed the effects of each variable. Power, Pressure, and NF3 Flow all had P-values close to 0, indicating strong statistical significance. The weight for Flow is 15.68, and the weights for Power and Pressure are 4.45 and 5.24, respectively, showing effects 3 and 7 times greater than those with the 6-inch equipment on the cleaning rate. Additionally, we analyzed the cleaning Stdev and derived that there is a trade-off between increasing the cleaning Rate and reducing the cleaning Stdev.

Keywords

Acknowledgement

This paper presents research conducted as part of the collaborative semiconductor major track project supported by the Korea Industrial Technology Foundation (G02P1 8800005502) in 2024. We would like to express our gratitude to Professor Woo-sig Min and Researcher Eun-beom Lee at the Semiconductor Process Diagnosis Research Institute of Myongji University for their assistance in the experiments

References

  1. Kwon, G. C., Kim, W. J., Lee, T. H., Lee, H. H., Kwon, H. T., & Shin,G. W. "Investigating the Wafer Temperature in an Atmospheric-Pressure Plasma Process," Journal of the Korean Physical Society, 77, 477-481, (2020). 
  2. K. J. Kim, C. H. Oh, N. Lee, J. H. Kim, J. W. Bae, G. Y. Yeom and S. S. Yoon, "Global Warming Gas Emission during Plasma Cleaning Process of Silicon Nitride using C-C4F8O/O2 Chemistry with Additive Ar and N2," Journal of Vacuum Science &Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena, vol. 22, no.2, pp. 483-488, (2004). 
  3. K. Yang, S. Park and G. Yeom, "Low global warming potential alternative gases for plasma chamber cleaning," Sci. Adv. Mater., vol. 8, no. 12, pp. 2253-2259, (2016). 
  4. H. Chae and H. H. Sawin, "Plasma Kinetic Study of Silicon-Dioxide Removal with Fluorocompounds in a Plasma-Enhanced Chemical Vapor Deposition Chamber," J. Kor. Phys. Soc., vol. 51, no. 3, pp. 978-983, (2007). 
  5. B. Ji, J. H. Yang, P. R. Badowski and E. J. Karwacki, "Optimization and Analysis of NF 3 in Situ Chamber Cleaning Plasmas," J. Appl. Phys., vol. 95, no. 8, pp. 4452-4462, (2004). 
  6. Woytek, A. J., J. T. Lileck, and J. A. Barkanic. "Nitrogen trifluoride A new dry etchant gas." Solid state technology 27.3 : 172-175, (1984). 
  7. Barkanic, J. A., et al. "Plasma-Etching Using NF3-A Review." Solid State Technology 32.4 : 109-115, (1989). 
  8. M. Czerniak, "PFC emission reduction in the semiconductor industry," in Proc. TMS Annu. Meet. Exhibit., pp. 1495-1498, (2018). 
  9. T. Yonemura et al., "Evaluation of FNO and F3NO as substitute gases for semiconductor CVD chamber cleaning," J. Electrochem. Soc., vol. 150, no. 11, pp. G707-G710, (2003). 
  10. Kim, W., Bang, I., Kim, J., Park, Y., Kwon, H., Shin, G., Kang, M., Cho, Y., Kwon, B., Kwak, J., & Kwon, G. . "Silicon Oxide Etching Process of NF3and F3NO Plasmas with a Residual Gas Analyzer" Materials14, no. 11, (2021). 
  11. S. An, J. E. Choi, J. E. Kang, J. Lee and S. J. Hong, "Eco-Friendly Dry-Cleaning and Diagnostics of Silicon Dioxide Deposition Chamber," in IEEE Transactions on Semiconductor Manufacturing, vol. 37, no. 2, pp. 207-221, May (2024). 
  12. D.H.Ka. "Characterization of a transformer-coupled toroidal remote plasma source for silicon oxide chamber cleaning." A Masters Thesis Submitted to the Department of Nano Science and Technology, Sungkyunkwan University, (2018).