Our work in ellipsometry centers around the development of ellipsometric instrumentation.  One of the instruments that we have developed is an angular scanning ellipsometer, and the requisite software to control its operation, and analyze the acquired data. The basic concept behind the angular scanning ellipsometer is described in the article entitled "Angular Scanning Mechanism for Ellipsometers", by D. M. Byrne and D. L. MacFarlane, Applied Optics, Vol. 30, No. 31, November 1, 1991. My students and I are currently callibrating and testing the optical assembly. In our calibration and checkout of our prototype instrument, we have uncovered a couple of design "glitches" that we are currently fixing.  

We have made modifications to our original design that we've recently implemented and are now considering further modifications to the basic platform to make the instrument suitable to obtain scatterometric data. Within this redesign effort, we have conceived several hardware oriented tasks that are suitable for undergraduate senior design projects or masters theses.  I have also conceived of some analytical tasks that are related to system modeling of the ellipsometer, in its original configuration, and to its operation as a scatterometer and to the analysis of data collected by our instrument.

Sometimes our work involves the analysis of ellipsometric data to find the optical properties of special materials or systems.  For example, we have applied ellipsometric analysis (1) to determine the refractive index and thickness of amorphous hydrogenated carbon films, correlating our results with process parameters, (2) to determine the refractive index of ion implanted silicon to determine if ellipsometry could detect variations in dose or implant energy, and (3) to determine the refractive index and thickness of organic conducting polymer films, to correlate with other analytical methods of film characterization.  All of our ellipsometric measurements to date were made using a Gaertner Dual Wavelength Angular Scanning Ellipsometer.   The two wavelengths in this instrument are created by He-Ne lasers, one operating at 0.6328 micrometers, and one operating at 1.523 micrometers.  There is always "room" for developing new approaches aimed at ellipsometric data analyses.

We also have other ellipsometers available for our use, the newest being a broadband instrument operating at a fixed angle of incidence of about 72⁰.  It is photo-elastic modulator based ellipsometer.  To support our studies of material properties, we also have an 'N&k instrument' from N&k Technologies, Inc.  This is a broadband reflectometer/transmissometer that is routinely used for film thickness and refractive index and for substrate refractive index. 

My present endeavors center around analyses of the optimum angles/wavelengths at which to measure a scatterometric signature.  The proper establishment of an optimum measurement scenario should lead to an optimum instrumental configuration, and hence, a configuration that is more economical to build and operate.