MINIMAL-DATA APPROACHES FOR DETERMINING OUTER-LAYER DIELECTRIC RESPONSES OF FILMS FROM KINETIC REFLECTOMETRIC AND ELLIPSOMETRIC MEASUREMENTS

For stratified samples where material is being uniformly deposited or removed at a known rate, the dielectric response epsilon0 of the outermost few angstrom is exactly determinable from the value and thickness derivative of the complex reflectance without any knowledge of the underlying structure. For ellipsometric data the equivalent analysis is not exact, but a common-pseudosubstrate approximation is developed, that in applications to semiconductor crystal growth, is accurate to better than 0.1 %.