It would not have been possible to write this doctoral thesis without the help and support of the kind people around me, to only some of whom it is possible to give particular mention here.
Foremost, I would like to express my sincere gratitude to my supervisor and friend Prof. Hans Kosina, for the continuous support of my Ph.D study and research, for his patience, help, support, and motivation. My sincere thanks also goes to Dr. Neophytos Neophytou and Dr. Mahdi Pourfath for their help and guidance in research during my Ph.D. studies, as well as in writing this thesis.
The Institute for Microelectronics has supported me to complete my thesis. My special thanks goes to Prof. Siegfried Selberherr, Prof. Erasmus Langer, and Prof. Tibor Grasser.
I am very grateful to DI Wolfhard H. Zisser who helped me during the transition to my new life in Vienna. I also thank him for translating the abstract of my thesis from English to German.
In addition, I have been very privileged to get to know and to collaborate with many other great people who became friends over the last few years. Hereby, I would like to thank the following (in alphabetical order):
Oskar Baumgartner, Markus Bina, Hajdin Ceric, Johann Cervenka, Raffaele Alberto Coppeta, Lado Filipovic, Lidija Filipovic, Wolfgang Gös, Ewald Haslinger, Philipp Hehenberger, Manfred Katterbauer, Hiwa Mahmoudi, Alexander Makarov, Mahdi Moradinasab, Mihail Nedjalkov, Roberto Orio, Dmitry Osintsev, Vassil Palankovski, Karl Rupp, Franz Schanovsky, Anderson Singulani, Zlatan Stanojevic, Viktor Sverdlov, Oliver Triebl, Stanislav Tyaginov, Paul-Jürgen Wagner, Michael Waltl, Josef Weinbub, Thomas Windbacher, and Renate Winkler.
Last but not the least, I would like to thank my parents, for supporting me spiritually throughout my life.