Semiconductor device manufacturing: process – With measuring or testing – Optical characteristic sensed
Reexamination Certificate
2006-05-23
2006-05-23
Lebentritt, Michael (Department: 2812)
Semiconductor device manufacturing: process
With measuring or testing
Optical characteristic sensed
Reexamination Certificate
active
07049156
ABSTRACT:
The present invention is directed to a system, method and software program product for calculating metrological data (e.g. layer thicknesses and depths of recesses and trenches) on a surface or structure, such as a semiconductor wafer. The present method does not require knowledge of the reflectivity or transmissivity of the surface or structure, but only a quantity related to the reflectivity or transmissivity linear transformation needs to be known. Initially, a simplified optical model for the process is constructed using as many parameters as necessary for calculating the surface reflectivity of the discrete regions on the wafer. Reflectivity data are collected from the surface of a wafer using, for instance, in-situ monitoring, and nominal reflectivity is determined from the ratio of the current spectrum to a reference spectrum. The reference spectrum is taken from a reference wafer consisting entirely of a material in which the reflection properties are well characterized. Both the observed and calculated data are transformed such that their vertical extents and spectrally averaged values coincide. By transforming both the observed data and calculated model such that their vertical extents and spectrally averaged values coincide, large errors in both the data and the model can be tolerated. A merit function is employed which measures the agreement between observed data and the model with a particular choice of parameters. The merit function may be minimized using a standard numerical technique for finding a deep minimum in the merit function at the correct values of the parameters.
REFERENCES:
patent: 4988198 (1991-01-01), Kondo
patent: 5392118 (1995-02-01), Wickramasinghe
patent: 5555472 (1996-09-01), Clapis et al.
patent: 5587792 (1996-12-01), Nishizawa et al.
patent: 5900633 (1999-05-01), Solomon et al.
patent: 6281974 (2001-08-01), Scheiner et al.
patent: 6590636 (2003-07-01), Nishi
Buchel, Jr. Rudolph J.
Lebentritt Michael
Verity Instruments Inc.
LandOfFree
System and method for in-situ monitor and control of film... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method for in-situ monitor and control of film..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method for in-situ monitor and control of film... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3624820