Optics: measuring and testing – By polarized light examination – Of surface reflection
Reexamination Certificate
2007-03-13
2007-03-13
Lee, Hwa (Andrew) (Department: 2877)
Optics: measuring and testing
By polarized light examination
Of surface reflection
C356S630000
Reexamination Certificate
active
10945167
ABSTRACT:
A method of determining the actual properties of a film stack. An incident beam of light is directed towards the film stack, such that the incident beam of light is reflected from the film stack as a reflected beam of light. The actual properties of the reflected beam of light are measured, and properties of the film stack are estimated. A mathematical model of the film stack is solved with the estimated properties of the film stack to yield theoretical properties of the reflected beam of light. The theoretical properties of the reflected beam of light are compared to the actual properties of the reflected beam of light to yield a cost function. The estimated properties of the film stack are iteratively adjusted and the mathematical model is iteratively solved until the cost function is within a desired tolerance. The estimated properties of the film stack are reported as the actual properties of the film stack. A method based on analytical derivatives, and not numerically computed derivatives, of solutions to Maxwell's equations that are at least partially expressible as complex exponential matrices is used to iteratively adjust the estimated properties of the film stack.
REFERENCES:
patent: 4999014 (1991-03-01), Gold et al.
patent: 5121337 (1992-06-01), Brown
patent: 6782337 (2004-08-01), Wack et al.
Li,Formulation and Comparison of Two Recursive Matrix Algorithms for Modeling Layered Diffraction Grating, J. Opt. Soc. Am., vol. 13, No. 5, pp. 1024-1035 (1996).
Moharam et al.,Formulation for Stable and Efficient Implementation of the Rigorous Coupled-Wave Analysis of Binary Gratings, J. Opt. Soc. Am., vol. 12, No. 5, pp. 1068-1076 (1995).
Aoyagi Paul
Flanner, III Philip D.
Poslavsky Leonid
KLA-Tencor Technologies Corporation
Lee Hwa (Andrew)
Luedeka Neely & Graham P.C.
Punnoose Roy M.
LandOfFree
Film measurement does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Film measurement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Film measurement will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3760394