Acknowledgment

I thank all the kind people who helped and supported me to do this doctoral thesis.

First and foremost, I would like to express my sincere gratitude to my supervisor Prof. Hans Kosina, for the continuous support of my PhD study and research, for his patience, help, and motivation. My sincere thanks goes to Dr. Mahdi Pourfath for his help and support in all the time of research and writing of this thesis.

The Institute for Microelectronics has supported me to complete my thesis. My special thanks goes to Prof. Siegfried Selberherr and Prof. Erasmus Langer for providing excellent working conditions, for the possibility to work at such a prestigious place, and for the opportunity to attend several international scientific conferences.

I also want to express my gratitude to other members of the institute. I would like to thank the following (in alphabetical order):
Oskar Baumgartner, Markus Bina, Hajdin Ceric, Johann Cervenka, Raffaele Alberto Coppeta, Paul Ellinghaus, Lado Filipovic, Lidija Filipovic, Joydeep Ghosh, Klaus-Tibor Grasser, Alexander Grill, Wolfgang G¨os, Ewald Haslinger, Philipp Hehenberger, Yury Illarionov, Markus Jech, Markus Kampl, Hossein Karamitaheri, Manfred Katterbauer, Hiwa Mahmoudi, Alexander Makarov, Andreas Morhammer, Mihail Nedjalkov, Neophytos Neophytou, Roberto Orio, Dmitry Osintsev, Vassil Palankovski, Santo Papaleo, Marco Rovitto, Florian Rudolf, Karl Rupp, Gerhard Rzepa, Franz Schanovsky, Prateek Sharma, Anderson Singulani, Zlatan Stanojevic, Viktor Sverdlov, Michael Thesberg, Oliver Triebl, Stanislav Tyaginov, Bianka Ullmann, Michael Waltl, Josef Weinbub, Yannick Wimmer, Thomas Windbacher, Renate Winkler, and Wolfhard Zisser.

I also want to thank my friends, especially Behzad Ebrahimi, who accompanied me during my student days and curiously followed my life as a researcher.

Last but not the least, I would like to thank my parents, for supporting me spiritually throughout my life.