Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
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OES based PECVD Process Monitoring Accuracy Improvement by IR Background Signal Subtraction from Emission Signal

적외선 배경신호 처리를 통한 OES 기반 PECVD공정 모니터링 정확도 개선

  • Received : 2019.01.14
  • Accepted : 2019.03.17
  • Published : 2019.03.31
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Abstract

Optical emission spectroscopy is used to identify chemical species and monitor the changes of process results during the plasma process. However, plasma process monitoring or fault detection by using emission signal variation monitoring is vulnerable to background signal fluctuations. IR heaters are used in semiconductor manufacturing chambers where high temperature uniformity and fast response are required. During the process, the IR lamp output fluctuates to maintain a stable process temperature. This IR signal fluctuation reacts as a background signal fluctuation to the spectrometer. In this research, we evaluate the effect of infrared background signal fluctuation on plasma process monitoring and improve the plasma process monitoring accuracy by using simple infrared background signal subtraction method. The effect of infrared background signal fluctuation on plasma process monitoring was evaluated on $SiO_2$ PECVD process. Comparing the $SiO_2$ film thickness and the measured emission line intensity from the by-product molecules, the effect of infrared background signal on plasma process monitoring and the necessity of background signal subtraction method were confirmed.

Keywords

References

  1. Stillahn, J. M., Trevino, K. J., and Fisher, E. R., "Plasma diagnostics for unraveling process chemistry," Annu. Rev. Anal. Chem., Vol. 1, pp. 261-291, 2008. https://doi.org/10.1146/annurev.anchem.1.031207.112953
  2. Pan, C. R., Zhou, M. C., Qiao, Y., and Wu, N. Q., "Scheduling cluster tools in semiconductor manufacturing: Recent advances and challenges," IEEE Trans. Autom. Sci. Eng., Vol. 15, pp. 1-16, 2018. https://doi.org/10.1109/TASE.2018.2872643
  3. Qin, S. J., Cherry, G., Good, R., Wang, J., and Harrison, C. A., "Semiconductor manufacturing process control and monitoring: A fab-wide framework," J. Process Contr., Vol. 16, pp. 179-191, 2006. https://doi.org/10.1016/j.jprocont.2005.06.002
  4. Khan, A. A., Moyne, J. R., and Tilbury, D. M., "An approach for factory-wide control utilizing virtual metrology," IEEE Trans. semicond. Manuf., Vol. 20, pp. 364-375, 2007 https://doi.org/10.1109/TSM.2007.907609
  5. Lee, Y. G., Lee, M. H., and Jeong, J. U., "Plasma electron temperature and metastable density measurement by using argon 4p level emission analysis (OES)," Spring Conference of KSDET, pp. 104-108, 2007.
  6. Yang, J., McArdle, C., and Daniels, S., "Dimension Reduction of Multivariable Optical Emission Spectrometer Datasets for Industrial Plasma Processes," Sensors, Vol. 14, pp. 52-67, 2014. https://doi.org/10.3390/s140100052
  7. Ma, B., McLoone, S., Ringwood, J., and MacGearailt, N. "An analysis of noise on optical emission spectroscopy measurements," Proc. ISSC, pp. 186-191, 2010.
  8. Bogart, K. H. A., Cushing, J. P., and Fisher, E. R., "Effects of Plasma Processing Parameters on the Surface Reactivity of OH($X^2{\Pi}$) in Tetraethoxysilane/$O_2$ Plasmas during Deposition of $SiO_2$," J. Phys. Chem. B, Vol. 101, pp. 10016-10023, 1997. https://doi.org/10.1021/jp971596o