유전알고리즘과 커널 부분최소제곱회귀를 이용한 반도체 공정의 가상계측 모델 개발

Development of Virtual Metrology Models in Semiconductor Manufacturing Using Genetic Algorithm and Kernel Partial Least Squares Regression

  • 김보건 (삼성전자 메모리 사업부) ;
  • 염봉진 (KAIST 산업 및 시스템 공학과)
  • Kim, Bo-Keon (Memory Division, Samsung Electronics) ;
  • Yum, Bong-Jin (Department of Industrial and System Engineering, KAIST)
  • 투고 : 2009.12.23
  • 심사 : 2010.04.06
  • 발행 : 2010.09.01

초록

Virtual metrology (VM), a critical component of semiconductor manufacturing, is an efficient way of assessing the quality of wafers not actually measured. This is done based on a model between equipment sensor data (obtained for all wafers) and the quality characteristics of wafers actually measured. This paper considers principal component regression (PCR), partial least squares regression (PLSR), kernel PCR (KPCR), and kernel PLSR (KPLSR) as VM models. For each regression model, two cases are considered. One utilizes all explanatory variables in developing a model, and the other selects significant variables using the genetic algorithm (GA). The prediction performances of 8 regression models are compared for the short- and long-term etch process data. It is found among others that the GA-KPLSR model performs best for both types of data. Especially, its prediction ability is within the requirement for the short-term data implying that it can be used to implement VM for real etch processes.

키워드

참고문헌

  1. Bishop, C. M. (2006), Pattern Recognition and Machine Learning, Springer.
  2. Bro, R. and Elden, L. (2008), PLS works, Journal of Chemometrics, 23, 69-71.
  3. Chang, Y. C. and Cheng, F. T. (2005), Application Development of Virtual Metrology in Semiconductor Industry, Proc. of the 31st Annual Conference of the IEEE Industrial Electronics Society, 124-129.
  4. Chang, Y. J., Kang, Y., Hsu. C. L., Chang, C. T., and Chan, T. Y. (2006), Virtual Metrology Technique for Semiconductor Manufacturing, 2006 International Joint Conference on Neural Networks, 5289-5293.
  5. Chen, Y. T., Yang, H. C., and Cheng, F. T. (2006), Multivariate Simulation Assessment for Virtual Metrology, Proceedings of the 2006 IEEE International Conference on Robotics and Automation, 1048-1053.
  6. Hung, M. H., Lin, T. H., Cheng, F. T., and Lin, R. C. (2007), A Novel Virtual Metrology Scheme for Predicting CVD Thickness, IEEE/ASME Transactions on Mechatronics, 12(3), 308-316. https://doi.org/10.1109/TMECH.2007.897275
  7. Jhonson, R. A. (2007), Applied Multivariate Statistical Analysis, 6th edition, Pearson Education.
  8. Khan, A. A., Moyne, J. R., and Tilbury, D. M. (2008), Virtual Metrology and Feedback Control for Semiconductor Manufacturing Processes Using Recursive Partial least squares, Journal of Process Control, 18, 961-974. https://doi.org/10.1016/j.jprocont.2008.04.014
  9. Kim, K. P., Lee, J. M., and Lee. I. B. (2005), A Novel Multivariate Regression Approach Based on Kernel Partial Least Squares with Orthogonal Signal Correction, Chemometrics and Intelligent Laboratory Systems, 79, 22-30. https://doi.org/10.1016/j.chemolab.2005.03.003
  10. Lin, T. H., Cheng, F. T., Wu, W. M., Kao, C. A., Ye, A. J., and Chang, F. C. (2009), NN_Based Key Variable Selection Method for Enhancing Virtual Metrology Accuracy, IEEE Transactions on Semiconductor Manufacturing, 22(1), 204-211. https://doi.org/10.1109/TSM.2008.2011185
  11. Su, Y. C., Hung, M. H., Cheng, F. T., and Chen, Y. T. (2006), A Processing Quality Prognostics Scheme for Plasma Sputtering in TFT-LCD Manufacturing, IEEE Transactions on Semiconductor Manufacturing, 19(2), 183-194. https://doi.org/10.1109/TSM.2006.873514
  12. Su, Y. C., Lin, T. H., Cheng, F. T., and Wu, W. M. (2008), Accuracy and Real-Time Considerations for implementing various Virtual Metrology Algorithms, IEEE Transactions on Semiconductor Manufacturing, 21(3), 426-434. https://doi.org/10.1109/TSM.2008.2001219
  13. Wasserman, G. S. and Sudjianto, A. (1994), All Subsets Regression Using a Genetic Search Algorithm, Computers and industrial Engineering, 27, 489-492. https://doi.org/10.1016/0360-8352(94)90341-7
  14. Yum, G. Y. (2006), Plasma Etch Technology, Miraecom.
  15. Zeng, D. K., Tan, Y. J., and Spanos, C. J. (2008), Dimensionality Reduction Methods in Virtual Metrology, Proceedinds of SPIE, 6922, 692238.1-692238. 11.