Patent ID: 7933026

Claim:
A method of generating a map of a test wafer illustrating the uniformity of a process comprising the steps of: scanning the surface of a test wafer with a first laser probe beam, with the spot size of the first laser probe beam on the test wafer being on the order of one micron; detecting the reflected first laser probe beam and generating first output signals; comparing the first output signals to stored calibration information, said calibration information being generated by scanning a region on the surface of a calibration wafer with a second laser probe beam, with the spot size of the second laser probe beam on the calibration wafer being on the order of one micron and detecting the reflected second laser probe beam and generating second output signals and by directing a broadband probe beam to said region on the calibration wafer, with the spot size of the broadband probe beam on the wafer being larger than the spot size of the laser probe beam and detecting the reflected broadband probe beam and generating third output signals as a function of wavelength and analyzing the characteristics of the calibration wafer based on the third output signals and correlating the results of the analysis with the second output signals; and generating a two dimensional map of variations in the characteristics of the test wafer based on the comparison of the first output signals to the calibration information.