D I S S E R T A T I O N

Dislocation Modeling in III-Nitrides

ausgeführt zum Zwecke der Erlangung des akademischen Grades
eines Doktors der technischen Wissenschaften

eingereicht an der Technischen Universität Wien
Fakultät für Elektrotechnik und Informationstechnik

von

Raffaele Alberto Coppeta
Rennweg 57/13
A-1030 Wien, Österreich
Matr. Nr. 1129950
geboren am 22 März 1986 in Torino, Italien

Wien, im June 2015      

Contents
List of Figures
List of Tables
1  Introduction
 1.1  Introduction: gallium nitride and related alloys (III-nitrides)
 1.2  GaN applications and characteristics
 1.3  Physical properties of III-nitrides
 1.4  Defects in III-nitrides
 1.5  Outline of the thesis
2  Elements of elasticity theory
 2.1  Introduction
 2.2  Fundamental equations
 2.3  Transformations
3  Dislocation energy
 3.1  Introduction
 3.2  Dislocation energy
 3.3  Dislocation in an isotropic continuum
 3.4  Dislocation in an anisotropic continuum
 3.5  Pre-logarithmic coefficients
 3.6  Comparison of pre-logarithmic terms based on a continuum and atomistic approach
 3.7  Dislocation configurations
 3.8  Summary
4  Critical Thickness
 4.1  Introduction
 4.2  The critical thickness criterion
 4.3  Impact of the anisotropy on the critical thickness criterion
 4.4  The critical thickness according to Willis, Jain and Bullough
 4.5  Overall comparison of various effects on the predicted critical thickness
 4.6  Comparison between theoretical and experimental critical thicknesses
 4.7  Summary
5  Reduction of the threading dislocation density
 5.1  Introduction
 5.2  Mathis Model
 5.3  Misfit dislocation density
 5.4  Threading dislocation density in heterostructures
 5.5  Summary
6  Conclusions and outlook
Bibliography
List of Publications
 Publications in Scientific Journals
 Publications in Conference Proceedings
Curriculum Vitae