Abstract
A new self-reference signal processing technique is proposed for detecting the location of irregularities and defects in a periodic two-dimensional signal or image. Using high-resolution spectral estimation algorithms, the proposed technique first extracts the period and structure of repeated patterns from the image. Then a defect-free reference image for comparison with the actual image is produced. Since the technique acquires all the information needed from a single image (in contrast to most existing methods), there is no need for a database image, a scaling or alignment procedure or any a priori knowledge about the repetition period of the patterns.
Potential application fields for the proposed method range from the area of wafer and mask defect inspection, which includes inspection of memory chips, shift registers, switched capacitors, CCD arrays, and LCD displays to other areas that deal with repeated structures, such as crystallography. Some results of applying the proposed technique to real images from microlithography are presented.
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References
Babian F (1986) Optical defect detection limits in semiconductor wafers and masks. PhD thesis, Stanford University, Stanford, Calif.
Barth M, Hirayama D, Beni G, Hackwood S (1992) A color vision inspection system for integrated circuit manufacturing. IEEE Trans Semiconductor Manufacturing 5:290–301
Browning R, Lincoln I, Stonestorm P (1989) Recent advances in automated patterned wafer inspection. Proceedings SPIE, Integrated Circuit Metrology, Inspection, and Process Control III, pp 440–445
Burg JP (1975) Maximum entropy spectral analysis. PhD thesis, Stanford University, Stanford, Calif.
Capon J (1983) Maximum-likelihood spectral estimation, In: Haykin, (ed) Nonlinear methods of spectral analysis, 2nd edn, chapter 5. Springer Berlin Heidelberg New York
Chae S (1987) Defect detection and classification in VLSI pattern inspection. PhD thesis, Stanford University, Stanford, Calif.
Dom BE, Brecher VH, Bonner R, Batchelder JS, Jaffe RS (1988) The P300: a system for automatic patterned wafer inspection. Machine vision Appl 1:205–221
Ejiri M, Uno T, Mese M, Ikeda S, (1973) A process for detecting defects in complicated patterns. Comput Graph Image Processing 2:326–339
Kayaalp AE, Jain R (1985) A knowledged-based automatic on-line wafer (IC) inspection system. Proceedings VISION 85, pp 117–130
Lin LH, Cavan DL, Howe RB, Graves RE (1985) A holographic photomask defect inspection system. Proceedings SPIE, Optical Microlithography IV, pp 110–116
Miayzaki Y, Tanaka H, Kosaka N, Tomada T (1992) Surface defect inspection system with an optical spatial frequency filter for semi conductor patterned wafers. Proceedings SPIE, Integrated Circuit Metrology, Inspection, and Process Control VI, pp 515–525
Paulraj A, Roy R, Kailath T (1985) Estimation of signal parameters by rotational invariance techniques (ESPRIT). Proceedings of the 19th Asilomar Conference on Circuits, Systems and Computers
Roy R, Kailath T (1989) ESPRIT: Estimation of signal parameters via rotational invariance techniques. IEEE Trans ASSP 37:984–995
Schmidt RO (1981) A signal subspace approach to multiple emitter location and spectral estimation, PhD thesis, Stanford University, Stanford, Calif.
Tanaka H, Miayzaki Y, Mikami N, Kosaka N, Tomada T (1988) Inspection of patterned wafer surface using eletro-optic spatial light modulator. Proceedings Optical Computing, pp 144–147
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Khalaj, B.H., Aghajan, H.K. & Kailath, T. Patterned wafer inspection by high resolution spectral estimation techniques. Machine Vis. Apps. 7, 178–185 (1994). https://doi.org/10.1007/BF01211662
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DOI: https://doi.org/10.1007/BF01211662