Dept. of Computer Science and Electrical Engineering
Oregon Health & Science University
A far ultraviolet (UV) spectroscopic ellipsometer system working up to 9 eV has been developed and applied to characterize high-K- dielectric materials. These materials have been gaining greater attention as possible substitutes for Si02 as gate dielectrics in aggressively scaled silicon devices. The optical properties of representative high-K bulk crystalline, epitaxial, and amorphous films, were investigated with far UV spectroscopic ellipsometry and some by visible-near UV optical transmission measurements. Optical dielectric functions and optical band gap energies for these materials are obtained from these studies. The spectroscopic data and results provide information that is needed to select viable alternative dielectric candidate materials with adequate band gaps, and conduction and valence band offset energies for this application, and additionally to provide an optical metrology for gate dielectric films on silicon substrates. For materials with anisotropic structure such as single crystal DySC03and GdSc03 an analysis process was developed to determine the optical constant tensor.
OGI School of Science and Engineering
Cicerrella, Elizabeth, "Dielectric functions and optical bandgaps of high-K dielectrics by far ultraviolet spectroscopic ellipsometry" (2006). Scholar Archive. 2.