Daniel Franta, Jiří Vohánka, Martin Bránecký, Pavel Franta, Martin Čermák, Ivan Ohlídal, Vladimír Čech
Optical Properties of the Crystalline Silicon Wafers Described Using the Universal Dispersion Model
Journal of Vacuum Science & Technology B 37 (2019) 062907
The optical properties of a slightly boron doped float-zone crystalline silicon wafer are studied using ellipsometry and spectrophotometry in a wide spectral range from far IR to vacuum UV. One side of the wafer was cleaned in an argon plasma, which influenced the optical properties of silicon near the surface. The dielectric response of silicon was modeled using a simplified universal dispersion model which is constructed on the basis of parameterization of the joint density of states describing both the electronic and phonon excitations. Several variants of models describing phonon absorption and interband transitions are discussed. It was possible to accurately determine the optical constants of bulk silicon and the optical constants near the perturbed surface over a wide spectral range. These optical constants agree well with those found in other works. From the optical measurements it was also possible to determine the thickness of the wafer and the static value of resistivity, and the determined values agreed with nominal values specified for the wafer.
DOI: 10.1116/1.5122284
You can also contact one of the authors: franta@physics.muni.cz, vohanka@physics.muni.cz, 63855@mail.muni.cz, ohlidal@physics.muni.cz