Jan M. Knaup

The Mechanism of Interface State Passivation by NO

Preliminary results of a systematic theoretical study on the reactions of NO with a model 4H-SiC/SiO2 interface are presented. We show, that nitridation is a complex process, in which the balance between various mechanisms depends on doping and temperature. For weakly doped (1015-16 cm-3) n-type SiC, the crucial effect is an additional oxidation without creation of excess carbon at the interface.

The Search for Near Interface Oxide Traps - First-Principles Calculations on Intrinsic SiO2 Defects

The density of interface traps (Dit) in thermally oxidized SiC is unacceptably high for MOS device fabrication. The most severe problem is posed by the extremely high concentration of slow acceptor states near the conduction band edge of 4H-SiC. These states are attributed to near interface traps originating from (probably intrinsic) defects in the oxide. Here a systematic theoretical search is presented for possible defects in the oxide with an appropriate acceptor level. Supercell calculations using a hybrid functional approach (and resulting in a correct gap) on defects in alpha-quartz exclude the oxygen vacancy and the oxygen interstitial, as possible candidates. In contrast, these calculations predict interstitial silicon to have an acceptor level in the appropriate range. The carbon interstitial in silica has an acceptor level somewhat deeper than that. Occupation of these levels give rise to significant rearrangement of the environment, leading to a more extended defect structure.

A permutation invariant collective variable to track and drive vacancy dynamics in simulations of solids

Vacancy dynamics in oxides are vital for understanding redox reactions and resulting memristive effects or catalytic activity. We present a method to track and drive vacancies which we apply to metadynamics simulation of oxygen vacancies (V

Where Would the Electronic States of a Small Graphite-Like Carbon Island Contribute to the SiC/SiO2 Interface State Density Distribution?

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Defects in SiO2 as the possible origin of near interface traps in the SiC/SiO2 system: A systematic theoretical study

) in rutile, demonstrating its effectiveness. Using the density-functional based tight-binding method, it is possible to explore the free energy hyperplane of oxygen vacancies in TiO

Theoretical study of the mechanism of dry oxidation of 4H-SiC

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Computational studies on polymer adhesion at the surface of γ-Al2O3. I. The adsorption of adhesive component molecules from the gas phase

. We show that the migration of V

Initial steps toward automating the fitting of DFTB Erep(r).

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Defects of the SiC/SiO2 interface: energetics of the elementary steps of the oxidation reaction

in TiO

How the aggregation of oxygen vacancies in rutile based TiO

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