Development and design of very large-scale-integrated circuits requires the basic understanding of microscopic principles of carrier injection. In this work the transport behavior of electrons in silicon dioxide and the transmission rates at the silicon/silicon dioxide interface are investigated. These transmission rates are extended to account consistently for numeric multi-band structures within simulations of injection experiments and are used to characterize two different MOS structures.
Proceeding from existing models for the electronic transport in silicon dioxide, nonparabolic and numerical multi-band structures are under investigation. It is observed that nonpolar acoustic phonon scattering prevents carriers from polar runaway and stabilizes the electronic distribution. For low and intermediate electrical fields applied to the insulator we present fitting formulae for the average drift velocity as well as for the electron mobility.
Analyzing the injection of electrons from silicon into silicon dioxide the Fowler-Nordheim approximation is modified taking into account the quantum mechanical nature of tunneling within a trapezoidal potential well across a finite isolating domain. These transmission rates are extended for the case of thermionic emission of carriers into the oxide. Carriers are injected into the oxide and a subsequent postprocessing within the domain of the oxide can be performed. The dependence of the important parameters like the effective mass of electrons, the thickness of the oxide and the applied electric field are examined.
A combined Monte Carlo technique is applied to simulate stationary homogeneous injection experiments. Accounting for the transmission of electrons three different models are used to extract the injection rate defined as ratio of gate and bulk current. Compared with the Fowler-Nordheim approximation a reduction of the injection rate is observed, for quantum mechanical tunneling as well as in the case of thermionic emission with subsequent oxide transport of injected carriers.
In case of a 
MOSFET a consequent inclusion of gradual channel
approximation and of field dependent transmission rates for a full
two-dimensional Monte Carlo simulation is presented. Also discussed are both,
the degradation of the isolating qualities of the oxide layer and the impact of
different interface effects on gate currents during fabrication of modern
electronic devices.