Optics: measuring and testing – By polarized light examination – With light attenuation
Patent
1997-10-31
1999-10-05
Kim, Robert H.
Optics: measuring and testing
By polarized light examination
With light attenuation
356376, 356384, G01B 1100, G01B 1124, G01B 1102
Patent
active
059633298
ABSTRACT:
A method for nondestructively determining the line profile or topographical cross-section of repeating lines on a substrate is provided, including line thickness, line width, and the shape of the line edge. A substrate having a repeating structure, such as a grating, is illuminated with broad-band radiation. Diffracted radiation is collected, measured, and recorded as a function of wavelength to provide an intensity versus wavelength curve. An initial model of the line profile of the grating, a model of the broad band radiation shined on the grating, and a model of the interaction of the radiation with the model grating is provided to a data processing machine. The machine uses Maxwell's equations to calculate a model diffracted intensity versus wavelength curve, and the measured intensity curve is then compared with this modeled intensity versus wavelength curve. The line profile in the model is then adjusted and the model intensity curve recalculated to improve agreement between the measured and calculated intensity curves. The model is repeatedly adjusted and the intensity recalculated until the best agreement between the two intensity versus wavelength curves is achieved, thereby providing the line profile. The method similarly provides composition profiles, such as doping depth profiles and optical coating profiles by taking advantage of the relationship between index of refraction and composition.
REFERENCES:
patent: 4141780 (1979-02-01), Kleinknecht et al.
patent: 4408884 (1983-10-01), Kleinknecht et al.
patent: 4593368 (1986-06-01), Fridge et al.
patent: 4707610 (1987-11-01), Lindow et al.
patent: 4748335 (1988-05-01), Lindow et al.
patent: 5042949 (1991-08-01), Greenberg et al.
patent: 5164790 (1992-11-01), McNeil et al.
patent: 5349440 (1994-09-01), DeGroot
patent: 5363171 (1994-11-01), Mack
Diffraction Analysis of Dielectric Surface-relief Gratings, M. G. Moharam and T. K. Gaylord, vol. 72, No. 10/Oct. 1982/J. Opt. Soc. Am. pp. 1385-1392.
Formulation for Stable and Efficient Implementation of the Rigorous Coupled-wave analysis of Binary Gratings, M. G. Moharam, Eric B. Grann, and Drew A. Pommet, vol. 12, No. 5/May 1995/J. Opt. Soc. Am. pp. 1069-1076.
Linewidth Measurement of Gratings on Photomasks: A Simple Technique, S. Sohail H. Haqvi, Susan Gaspar, Kirt Hickman, Ken Biship, and John R. McNeil, Apr. 1, 1992/vol. 32, No. 10/Applied Optics pp. 1377-1384.
Stable Implementation of the rigorous Coupled-wave Analysis for Surface-Relief Gratings: Enhanced Transmittance Matrix Approach, M. G. Moharam, Drew A. Pommett, and Eric B. Grann vol. 12, No. 5/May 1995/J. Opt. Soc. Am.A, pp. 1077-1085.
Use of Light Scattering in Characterizing Reactively Ion Etched Profiles, Konstantinos P. Giapis, Richard A. Gottscho, Linda A. Clark, Joseph B. Kruskall, and Diane Lambert, AT&T Bell Laboratories, Murray Hill, NJ 07974 and Avi Kornblit and Dino Sinatore, AT&T Bell Laboratories, Allentown PA 18103, page No. and date not available.
Conrad Edward W.
Paul David P.
International Business Machines - Corporation
Kim Robert H.
Leas James M.
Merlino Amanda
LandOfFree
Method and apparatus for measuring the profile of small repeatin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for measuring the profile of small repeatin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for measuring the profile of small repeatin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1178131