Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
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Evaluation of Imaging Performance of Phase Shift Mask Depending on Reflectivity with Sub-resolution Assist Feature in EUV Lithography

SRAF를 적용한 극자외선 노광기술용 위상 변위 마스크의 반사도에 따른 이미징 특성 연구

  • Jang, Yong Ju (Department of Nanoscale Semiconductor Engineering, Hanyang University) ;
  • Kim, Jung Sik (Department of Nanoscale Semiconductor Engineering, Hanyang University) ;
  • Hong, Seongchul (Department of Materials Science and Engineering, Hanyang University) ;
  • Cho, HanKu (Institute of Nano Science and Technology, Hanyang University) ;
  • Ahn, Jinho (Department of Nanoscale Semiconductor Engineering, Hanyang University)
  • 장용주 (한양대학교 공과대학 나노반도체공학과) ;
  • 김정식 (한양대학교 공과대학 나노반도체공학과) ;
  • 홍성철 (한양대학교 공과대학 신소재공학과) ;
  • 조한구 (한양대학교 나노과학기술연구소) ;
  • 안진호 (한양대학교 공과대학 나노반도체공학과)
  • Received : 2015.08.18
  • Accepted : 2015.09.22
  • Published : 2015.09.30
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Abstract

In photolithography process, resolution enhancement techniques such as optical proximity correction (OPC) and phase shift mask (PSM) have been applied to improve resolution. Especially, sub-resolution assist feature (SRAF) is one of the most important OPC to enhance image quality including depth of focus (DOF). However, imaging performance of the mask could be varied with the diffraction order amplitude changed by inserting SRAF. Therefore, in this study, we investigated the imaging properties and process margin of attenuated PSM with SRAF. Reflectivities of attenuated PSMs at 13.5 nm were 3, 6, 9% and simulation was performed by $PROLITH^{TM}$. As a result, aerial image properties and DOF as well as diffraction efficiency were improved by increasing the reflectivity of attenuated PSM. Additionally, printed critical dimension variations depending on SRAF width and space error were also reduced for attenuated PSM with high reflectivity. However, SRAF could be printed when reflectivity of attenuated PSM is high enough. In conclusion, optimization of reflectivity of attenuated PSM and SRAF to prevent side-lobe from being printed is needed to be considered.

Keywords

References

  1. ITRS organization, "International technology roadmap for semiconductors 2013 edition : Lithography summary", 2013, from http://www.itrs.net
  2. C. Constancias, M. Richard, D. Joyeux, J. Chiaroni, R. Blanc, J.Y. Robic, E. Quesnel and V. Muffato., "Phase shift mask for EUV lithography", Proc. of SPIE, Vol. 6151, pp. 1-4, (2006).
  3. C. H. Clifford, Y. Zou, A. Latypov, O. Kritsun, T. Wallow, H. J. Levinson, F. Jiang, D. Civay, K. Standiford, R. Schlief, L. Sun, O. R. Wood, S. Raghunathan, P. Mangat, H. Peng Koh, C. Higgins, J. Schefske. and M. Singh., "EUV OPC for the 20nm node and beyond", Proc. of SPIE, Vol. 8322, pp. 1-14, (2012).
  4. M. Burkhardt, G. McIntyre, R. Schlief and L. Sun., "Clear sub-resolution assist features for EUV", Proc. of SPIE, Vol. 9048, pp. 1-7, (2014).
  5. F. Jiang, M. Burkhardt, A. Raghunathan, A. Torres, R. Gupta, and J. Word., "Implementation of assist features in EUV lithography", Proc. of SPIE, Vol. 9422, pp. 1-10, (2015).
  6. N. Davydova, E. van Setten, R. de Kruif, D. Oorschot, M. Dusa, C. Wagner, J. Jiang, W. Liu, H. Y. Kang, H. Liu, P. Spies, N. Wiese and M. Waiblinger., "Imaging performance improvements by EUV mask stack optimization", Proc. of SPIE, Vol. 7985, pp. 1-4, (2011).
  7. A. Erdmann and P. Evanschitzky., "Imaging characteristics of binary and phase shift masks for EUV projection lithography", Proc. of SPIE, Vol. 8550, pp. 1-10, (2012).
  8. S. Lee, I. Lee, J. Doh, J. U. Lee, S. Hong and J. Ahn., "Improved imaging properties of thin attenuated phase shift masks for extreme ultraviolet lithography", J. Vac. Sci. Technol. B 31(2) 021606, pp. 1-6, (2013).
  9. S. Hsu, R. Howell, J. Jia, H. Y. Liu, K. Gronlund, S. Hansen., and J. Zimmermann, "EUV resolution enhancement techniques (RETs) for k1 0.4 and below ", Proc. of SPIE, Vol. 9422, pp. 1-16, (2015).
  10. J. S. Kim, S. Hong, J. U. Lee, S. M. Lee, and J. Ahn., "Attenuated phase-shift mask for mitigation of photon shot noise effect in contact hole pattern for extreme ultraviolet lithography", Appl. Phys. Express, Vol. 7, pp. 1-4, (2014).
  11. S. Hong, S. Jeong, J. U. Lee, S. M. Lee, and J. Ahn., "Stochastic patterning simulation using attenuated phase-shift mask for extreme ultraviolet lithography", Appl. Phys. Express, Vol. 6, pp. 1-4, (2013).
  12. C. B. Tan, K. K. Koh, D. Zhang and Y. M. Foong., "Sub-resolution assist feature (SRAF) printing prediction using logistic regression", Proc. of SPIE, Vol. 9426, pp. 1-6, (2015).
  13. M. Coles, Y. S. Choi , K. Yang, C. Parker and A. Self., "Automated method of detecting SRAF and sidelobe printing with automated CD-SEM recipes", Proc. of SPIE, Vol. 6924, pp. 1-11, (2008).
  14. R. Viswanathan, J. T. Azpiroz and P. Selvam., "Process optimization through model based SRAF printing prediction", Proc. of SPIE, Vol. 8326, pp. 1-10, (2013).
  15. C. Burgel, M. Sczyrba and G. R. Cantrell., "A systematic approach to the determination of SRAF capabilities in high end mask manufacturing", Proc. of SPIE , Vol. 7823, pp. 1-11, (2010).