Observation of HfO2 thin films by deep UV spectroscopic ellipsometry

Modified Tauc–Lorentz dispersion model leading to a more accurate representation of absorption features below the bandgap

“…in microelectronic, photovoltaic and optoelectronic industries. Multiple studies on the HfO 2 optical properties have reported the presence of an absorption feature 0.2-0.3 eV below the optical band-gap energy E g and attributed this feature to the hafnium dioxide crystallinity or, in particular, to monoclinic phase of HfO 2 [38][39][40][72][73][74][75][76][77][78][79][80][81]. Similar sub-bandgap absorption feature has been also reported for atomic-layer-deposited (ALD) Al 2 O 3 [82].…”

First-Principles Study of Dynamical and Dielectric Properties of Orthorhombic Phases of Group IVb Transition Metal Oxides.

“…Similar studies were also performed for crystalline HfO 2 (9,11) and TiO 2 (10). In this paper, we extend these previous works by performing a thorough study of the orthorhombic phases of HfO 2 , ZrO 2 and TiO 2 that have been observed at high-pressure (14,15,16,17) or in thin films (18,19). Note that the dielectric constants of the orthorhombic phases of HfO 2 and ZrO 2 have also been calculated (20).…”

Optical and structural characterization of thermal oxidation effects of erbium thin films deposited by electron beam on silicon

“…In particular, the appearance of the shoulder peak around 5.5 eV in the absorption spectra is similar to the case reported in the literature for a dualphase hafnium oxide phase. 36 The absorption coefficient data for the shoulder peak was fit in the linear regime as shown in Fig. 11, yielding an intercept at $5.3 eV.…”