Due to the rapid progress of Si technology and the introduction of new device types and materials, it is a challenging task to develop and improve models for TCAD device simulation. In this development process it is essential to have access to reliable data from measurements, but as device fabrication gets more and more complex also experiments become more expensive and - as a major drawback - also more time consuming. As a consequence it is of increasing interest to obtain data by simulations based on more fundamental methods.
In this work it has been shown that Monte Carlo methods
based on a full-band dispersion relation are a powerful tool in this respect.
Full-band Monte Carlo is generally applicable to hot carrier problems, because
an accurate representation of the band structure at higher energies is
essential here. Beyond that, the simulator has been extended to handle
transport in arbritrarily strained Si, Ge and SiGe alloys. This is an
important feature, since modern high performance MOSFET devices rely heavily
on strain engineering techniques to increase the performance. It has been
exemplarily demonstrated that in Si the electron mobility is
increased by a
strain setup and that in Ge the higher hole
mobility compared to Si can be further increased by the introduction of
strain.
These effects are explained by an evaluation and theoretical interpretation of
band structure data from EPM calculations. It is concluded that the electronic
mobility increase or decrease, depending on the setup, stems from an energy
separation of the 
valleys, which also lifts their degeneracy, and from
a change in the effective masses in transport direction. For hole transport the
latter effect is also valid, but there is also a contribution from the relative
shift of the heavy hole, light hole and split-off bands.
It has been also demonstrated that the high computational costs of full-band
Monte Carlo can be reduced by the implementation of performance
optimizing features like rejection algorithms or irregular mesh
refinement in
-space. These features in combination with the
availability of successively increasing computational power indicate that
full-band Monte Carlo will play a stronger role in device simulation in the
future.
In this work Monte Carlo techniques are also applied to simulate blocked
impurity band photo detectors. These devices operate at temperatures below
. The scattering models were extended to
deliver valid results in this temperature range. Some simulation results of the
avalanche effect in blocked impurity band devices were presented. The avalanche
effect can be used to operate the devices as single photons detectors.