AVS 60th International Symposium and Exhibition
    Spectroscopic Ellipsometry Focus Topic Wednesday Sessions
       Session EL+AS+EM+SS+TF-WeA

Invited Paper EL+AS+EM+SS+TF-WeA9
Optical Properties of Nanoscale Nanoelectronic Materials

Wednesday, October 30, 2013, 4:40 pm, Room 101 A

Session: Spectroscopic Ellipsometry: Perspectives and Novel Applications
Presenter: A.C. Diebold, College of Nanoscale Science and Engineering
Correspondent: Click to Email
Nanoscale dimensions clearly alter the optical properties of materials. All too often, changes in key optical properties such as direct gap transitions are attributed to quantum confinement. The origin of changes in optical properties depends on several factors including crystal structure (poly-crystalline vs single crystal), material type (metal, semiconductor, or dielectric) and temperature. Temperature dependent determination of the dielectric function of ultra-thin silicon on insulator films show that electron-phonon interactions alter optical transitions. Thus changes in the phonon dispersion will alter room temperature optical properties. These changes can be due the films that surround the nanolayer. Other examples include silicon fins and silicon fins topped with Si(1-x)Gex layers. The Si fins are confined in two dimensions. Here the need for understanding anisotropic optical properties is described. The optical properties of metal films also show dimensional effects. The origin of the thickness dependence of the optical properties of poly-crystalline metal films can be traced to grain size. In this talk, the impact of nanoscale dimensions will be explored using examples that include ultra-thin silicon films, thin silicon “fin” structures, and poly-crystalline thin metal films.