Patent ID: 6417921
Filing Date: 2002-07-09
Classification: G01B

Abstract:
A method for analyzing a sample having a multiple layer thin film stack thereon comprising the steps ofgenerating a first probe beam from a laser having a narrowband output which is stable to within one percent; directing the first probe beam to reflect off the surface of the sample at a non-normal angle of incidence; analyzing the change in polarization state of the first probe beam induced by the interaction with the sample and generating first output signals in response thereto; generating a second probe beam from a broad band wavelength source; directing said second probe beam to reflect off the surface of the sample; monitoring the second probe beam after reflection from the sample and determining the change in polarization state at a plurality of wavelengths and simultaneously generating a plurality of second output signals corresponding thereto; and analyzing the characteristics of the thin film layers on the sample based on a combination of the first and second output signals.