| A novel technique, Image Scanning Ellipsometry, to measure the two dimensional thickness profile of a non-uniform, thin film, from several nm up to several {dollar}mu{dollar}m, in the transient state as well as in the steady state was developed and tested in this thesis. Image Scanning Ellipsometry (ISE) is a full-field imaging technique which can study every point on the surface at the same time with high spatial resolution and thickness sensitivity; i.e., it can measure and map a liquid or solid film thickness profile in two dimensions. The long-term objective of the development of ISE is to determine the stability and heat transfer characteristics of evaporating thin films. The main purpose of this thesis was to develop the basic concept of ISE and demonstrate its use by measuring the thickness profiles of non-uniform solid films in a steady state as well as the profile of draining liquid films of wetting and partially wetting fluids in a transient state.; In this thesis, ISE has been proven to be as accurate as a null ellipsometer by measuring a known solid wedge profile of ThF{dollar}sb4{dollar} on a Si substrate. In addition, the ability of ISE to measure liquid draining films such as FC-5311, FC-77, and FC-70 in a transient state was demonstrated. Moreover, ISE was also used to measure a partially wetting, draining film of dodecane, and to record the details of film rupture. The approximate solutions of a modeling equation for the thickness profile during draining was compared to the experimental profile. The agreement between theory and experiment is quite good. The theoretical profiles agree with the experimental profiles in both the thicker hydrodynamic region and in the thin film region which is under 100 nm.; However, because the current limited magnification of the ISE hinders the exact location of a null point and the allocation of the exact position of the dark fringes is limited by the ability to accurately digitize and analyze the images, discrepancies between the modeling and the experiments are expected. Moreover, since the initial draining film thickness is not infinite as assumed in the model, there is a difference between the real draining time and the model time. With calibration, this is not a hinderance to model evaluation.; The present ISE design is not optimum but can be easily improved by redesigning and rebuilding the instrument. Suggestions for improvement include replacing the optical components for improved resolution, using better image acquisition hardware, and faster data analysis tools. |
