In the electron energy loss spectra for amorphous, atomic layer deposited (ALD) Al2O3 film, a peak at 6.4 eV was observed. First principle quantum chemical simulation shows that it relates to excitation of neutral oxygen vacancy in Al2O3. The 2.91 eV luminescence excited in a band near 6.0 eV in amorphous Al2O3 is similar to that in bulk crystals which is associated with neutral oxygen vacancy. Thus, the amorphous ALD Al2O3 film is oxygen deficient and the oxygen vacancy parameters are similar in crystalline and amorphous Al2O3.

Electronic structure of oxygen vacancies in Ta₂O₅ have been studied theoretically by first-principles calculations and experimentally by x-ray photoelectron spectroscopy. Calculations of δ-Ta₂O₅ were performed using density functional theory within gradient-corrected approximation with the +U approach. Results indicate that the oxygen vacancy causes a defect level in the energy gap at 1.2 eV above the top of the valence band. To produce oxygen vacancies, amorphous films of Ta₂O₅ were bombarded with Ar⁺ ions. XPS results indicate that the Ar-ion bombardment leads to the generation of the oxygen vacancies in Ta₂O₅ that characterize the peak at 2 eV above the valence band. The calculated spectrum of crystalline δ-Ta₂O₅ demonstrates qualitative correspondence with the XPS spectrum of the amorphous Ta₂O₅ film after Ar-ion bombardment.

A theory for charge transport in dielectrics via tunneling between traps was developed. Unlike in the Frenkel model, in the present theory the traps are characterized with the thermal and optical ionization energies, and ionization proceeds by the multi-phonon mechanism. The theory predicts the tunneling between such traps to be a thermally stimulated process whose activation energy equals half to the difference between the optical and thermal ionization energies. The theory provides an adequate description to the experimental current-voltage characteristics of silicon-rich silicon nitride films. Such films have a high density of traps originating from the excess silicon present in the material, with charge transport proceeding as a charge carriers tunnel between closely spaced traps.

The atomic structure of amorphous and crystalline hafnium oxide $\left(\mathrm{Hf}{\mathrm{O}}_2\right)$ films was examined using x-ray diffractometry and Hf edge x-ray absorption spectroscopy. According to the x-ray photoelectron spectroscopy and band data calculated by the density functional method, we found that the valence band of $\mathrm{Hf}{\mathrm{O}}_2$ consists of three subbands separated by ionic gaps. The upper subband is formed by O $2p$ , Hf $4f$ , and Hf $5d$ states; the intermediate subband is formed by O $2s$ and Hf $4f$ states, whereas the lower narrow subband is mainly formed by Hf $5p$ states. The energy gap of amorphous $\mathrm{Hf}{\mathrm{O}}_2$ is $5.7\mathrm{eV}$ as determined by electron energy loss spectroscopy. The band calculation results indicate the existence of light $\left(0.3m_0\right)$ and heavy $\left(8.3m_0\right)$ holes in the $\mathrm{Hf}{\mathrm{O}}_2$ film and the effective mass of electron lies in the interval of $0.7m_0–2.0m_0$ .

Thermally assisted tunneling of holes at the ${\mathrm{A}\mathrm{u}-\mathrm{S}\mathrm{i}}_3{\mathrm{N}}_4$ interface was experimentally observed. The hole barrier of $1.6\pm 0.2\mathrm{eV}$ and the effective masses for the hole and electron tunneling into silicon nitride have been determined. A revised energy-band diagram of the metal-nitride-oxide-semiconductor structure is constructed.