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SFRF: Spatial Frequency Response Function Estimation Program



Thomas A. Germer, Clara C. Asmail


Measurements of optical scatter are often employed in production line diagnostics for surface roughness of silicon wafers. However, the geometry of the optical scatter instrumentation lacks universal standardization, making it difficult to compare values obtained by instruments made by different manufacturers. The biodirectional reflectance distribution function [BRDF], on the other hand, is a well-defined quantity, and under conditions usually met with bare silicon wafers, can be related to the power spectral density [PSD] of the surface roughness. In a separate paper, we presented an approach for characterizing low level optical scatter instrumentation using a spatial frequency response function. Methods for calculating or measuring the response function were presented. This program implements the methods of that approach to allow manufacturers of instruments that deduce surface microroughness by measuring the level of light scattering to evaluate the spatial frequency response for those instruments.
World Wide Web-Internet and Web Information Systems


haze, optical scatter, silicon wafer, software, surface roughness


Germer, T. and Asmail, C. (1997), SFRF: Spatial Frequency Response Function Estimation Program, World Wide Web-Internet and Web Information Systems, [online], (Accessed May 29, 2024)


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Created November 10, 1997, Updated February 17, 2017