Methods and systems are disclosed for analyzing a scanning interferometry signal. Steps include: providing a scanning interferometry signal produced by a scanning interferometer for a first location of a test object (e.g., a sample having a thin film); providing a model function of the scanning interferometry signal produced by the scanning interferometer, wherein the model function is parameterized by one or more parameter values; fitting the model function to the scanning interferometry signal for each of a series of shifts in scan position between the model function and the scanning interferometry signal by varying the parameter values; and determining information about the test object (e.g., a surface height or height profile, and/or a thickness or thickness profile for a thin film in the test object) at the first location based on the fitting.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/437,002, filed May 18, 2006, now U.S. Pat. No. 7,321,431, which claims priority to U.S. Provisional Patent Application Ser. No. 60/682,742, filed May 19, 2005 and entitled "METHOD AND SYSTEM FOR ANALYZING LOW-COHERENCE INTERFEROMETRY SIGNALS FOR SURFACE TOPOGRAPHY MEASUREMENT OVER THIN FILM STRUCTURES," the contents of both which are incorporated herein by reference.
