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The luminescence spectra of non-stoichiometric zirconium oxide film series with different oxygen vacancies' concentrations show the blue photoluminescence band centered near a 2.7 eV peak. There is a broad band at 5.2 eV in the luminescence excitation spectrum for blue emission. The ab-initio quantum-chemical calculation gives a peak in the optical absorption at 5.1 eV for the oxygen vacancy in cubic ZrO2. It was concluded that the 2.7 eV blue luminescence excited near 5.2 eV in a zirconium oxide film is associated with the oxygen vacancy. [ABSTRACT FROM AUTHOR]

The optical properties and composition of thermal silicon oxide thin films processed in a hydrogen electron cyclotron resonance plasma have been studied by ellipsometry, quantum-chemical modeling, and photoluminescence spectroscopy. It has been found that the plasma processing of the films leads to their oxygen depletion and the formation of nonstoichiometric oxide SiOx< 2. The parameter x of the obtained SiOx films has been determined by comparing the experimental spectral dependence of the refractive index with the dependence obtained theoretically using the ab initio calculation. It is shown that an increase in the time of processing of thermal dioxide SiO2 in a hydrogen plasma leads to an increase in the refractive index of the film, as well as in the degree of its oxygen depletion. The dependence of the parameter x of the investigated films on the hydrogen plasma processing time is plotted. [ABSTRACT FROM AUTHOR]

Amorphous silicon oxide SiO2, silicon nitride Si3N4, and silicon oxynitride SiOxNy are three key dielectrics in silicon devices. Implementation of nitrided oxide (oxynitride SiOxNy) as a gate dielectric in metal-oxide-semiconductor field effect transistors has been shown to significantly improve the reliability and lifetime of devices. Also, amorphous oxynitride is used as a tunnel dielectric in nonvolatile flash memory devices. The present paper is devoted to the experimental and theoretical study of silicon oxynitride electronic structure. The ionic formula of crystalline Si2N2O is deduced from the first principles. Effective masses of charge carriers in Si2N2O are calculated and compared with experimental data on tunnel injection in amorphous SiNxOy samples. Also experimental x-ray absorption and emission spectra are compared with the theoretically calculated ones. [ABSTRACT FROM AUTHOR]

The Si 2p x ray photoelectron spectra of SiOx with a different composition of 0 ≤ x ≤ 2 have been studied experimentally and theoretically. The SiOx films were prepared by low-pressure chemical vapor deposition from SiH4 and N2O source at 750 °C. Neither random bonding nor random mixture models can adequately describe the structure of these compounds. The interpretation of the experimental results is discussed according to a large scale potential fluctuation due to the spatial variation of chemical composition in SiOx. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The nature of electron and hole trapping in silicon ion-implanted silicon oxide (SiO2) with a dose of 1016 cm-2 were studied using photoluminescence and electron spin resonance (ESR) measurements. We observed an ESR signal with g = 2.006 after hole and electron injections. These results unambiguously imply that the Si nanoclusters created by the high-dose Si implants are both electron and hole traps in the SiO2 films. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A phonon-coupled trap model is proposed for trap-assisted injection mechanism in silicon-oxide-nitride-oxide-silicon (SONOS)/metal-nitride-oxide-silicon (MNOS) structures at low voltages. On the basis of this model, a theory of charge injection in SONOS/MNOS has been developed. Charge injection experimental data was fitted by this theory. Obtained trap parameters are close to those previously reported [K. A. Nasyrov et al., J. Appl. Phys. 96, 4293 (2004)], where the current dependence on temperature and electric field was investigated in MNOS. [ABSTRACT FROM AUTHOR]

A revised tight-binding Hamiltonian parametrization scheme for calculating the electronic structure of both covalent and ion-covalent solids is proposed. Unlike the conventional approaches, the present nonempirical calculation does not rely on any empirical parameter. We use the atomic properties of isolated atoms to construct the matrix elements. Results show that the predicted charge transfer in SiO2 and Si3N4, the bandgap energies of SiO2, Si3N4, and SiOxNy films, as well as the electron and hole barriers at the Si/SiO2, Si/Si3N4, and Si/SiOxNy interfaces are in good agreement with the experimental findings reported in literatures. [ABSTRACT FROM AUTHOR]

The atomic structure of amorphous and crystalline hafnium oxide (HfO2) 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 HfO2 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 HfO2 is 5.7 eV as determined by electron energy loss spectroscopy. The band calculation results indicate the existence of light (0.3m0) and heavy (8.3m0) holes in the HfO2 film and the effective mass of electron lies in the interval of 0.7m0–2.0m0. [ABSTRACT FROM AUTHOR]

The charge transport in the amorphous Si3N4 is studied experimentally and theoretically. We have found, that widely accepted Frenkel model of the trap ionization gives the unphysical low value of the attempt to escape factor, and the enormously high value of the electron tunnel mass. Experimental data are well described by theory of the two-bands conduction and the phonon-assisted trap ionization in Si3N4. [ABSTRACT FROM AUTHOR]