Patent ID: 6999180

Claim:
An apparatus capable of selectively measuring both topography and thickness of a sample, the apparatus comprising: a light source adapted to create a light beam a variable wavelength within a wavelength range, a splitter adapted to split the light beam into a reference beam and a sample beam, a reference mirror adapted to receive the reference beam and reflect it back along an imaging path, a sample holder adapted to hold the sample, where the sample receives the sample beam at a plurality of pixel locations within a field of view and reflects it back along the imaging path, a stage adapted to move at least one of the reference mirror along a first axis of the reference beam and the sample along a second axis of the sample beam, a detector adapted to receive both the reference beam and the sample beam from the plurality of pixel locations as the stage moves to a plurality of different positions along at least one of the first axis and the second axis, thereby generating a matrix of intensity values, and an analyzer for receiving the matrix of intensity values, the analyzer adapted to, arrange the intensity values for a given pixel location as the stage moves along at least one of the first axis and the second axis into an interferogram, perform a Fourier transform on the interferogram for each pixel location to produce an array of complex numbers, determine phase values from complex portions of the complex numbers, and use a model of film parameters to selectively iteratively regress at least one of the thickness and the topography of the sample at the plurality of pixel locations from the phase values.