A Wafer Pre-Alignment System Using One Image of a Whole Wafer

하나의 웨이퍼 전체 영상을 이용한 웨이퍼 Pre-Alignment 시스템

  • Koo, Ja-Myoung (Dept. of Electrical and Electronics Engineering, Korea University of Technology and Education) ;
  • Cho, Tai-Hoon (School of Computer Engineering, Korea University of Technology and Education)
  • 구자명 (한국기술교육대학교 전기전자공학과) ;
  • 조태훈 (한국기술교육대학교 컴퓨터공학부)
  • Received : 2010.08.23
  • Accepted : 2010.09.15
  • Published : 2010.09.30


This paper presents a wafer pre-alignment system which is improved using the image of the entire wafer area. In the previous method, image acquisition for wafer takes about 80% of total pre-alignment time. The proposed system uses only one image of entire wafer area via a high-resolution CMOS camera, and so image acquisition accounts for nearly 1% of total process time. The larger FOV(field of view) to use the image of the entire wafer area worsen camera lens distortion. A camera calibration using high order polynomials is used for accurate lens distortion correction. And template matching is used to find a correct notch's position. The performance of the proposed system was demonstrated by experiments of wafer center alignment and notch alignment.



  1. 나원석, "노치형 웨이퍼 정렬기 개발에 관한 연구," 한국항행학회지 제13권 제 3호, pp. 412-418, 2009.
  2. 박홍래, 유준, "웨이퍼 정렬법과 정밀도 평가," 제어.자동화.시스템공학회지, 제8권, 제9호, pp. 812-817, 2002.
  3. H.S. Lee, J.W. Jeon, J.W. Kim, S.J. Jung, and J.E. Byun, "A 12 inch wafer prealigner", Micoprocessors and Microsystems, vol. 27, pp.151-158, 2003. https://doi.org/10.1016/S0141-9331(02)00105-9
  4. 이남희, 조태훈, "고차 다항식 변환 기반 카메라 캘리브레이션을 이용한 웨이퍼 Pre-Alignment 시스템", 반도체디스플레이기술학회지, 제9권, 제1호, pp.11-16, 2010.
  5. 조태훈, "고차 polynomial을 이용한 정밀한 카메라 캘리브레이션", Proceedings of KFIS Spring Conference , Vol.17, No.1, pp.413-416, 2007.
  6. C. Steger, M. Ulrich, C. Wiedemann, "Machine Vision, Algorithms and Applications", WILEY-VCH, pp. 211-214, 2007.
  7. Qu Dongsheng, Quio Suilong, Rong Weibin, Song Yixu, Zhao Yanna, "Desing and Experiment of The wafer pre-alignment System," Proceedings of the 2007 IEEE International Conference on Mechatronics and Automation, pp. 1483-1488, 2007.