D i s s e r t a t i o n

Hole Trapping
and
the Negative Bias Temperature Instability

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

WOLFGANG GÖS

Malborghetgasse 31/5/53
A-1100 Wien, Österreich

Matr. Nr. 9827273
geboren am 24. Juli 1979 in Wien
Wien, im Dezember 2011

Contents
Kurzfassung
Abstract
Acknowledgements
Acronyms
Physical Quantities
Physical Constants
1 Introduction
 1.1 Definition of NBTI
 1.2 Two Main Contributions to NBTI
 1.3 NBTI Experiments
 1.4 Phenomenological Findings
 1.5 A Modeling Perspective
 1.6 Conclusion
2 Fundamentals of Charge Trapping
 2.1 Tunneling — A Process Depending on Device Electrostatics
 2.2 Franck-Condon Theory
 2.3 The Level Shift
 2.4 Nonradiative Multi-Phonon Theory
 2.5 Effective Rates into Single Traps
3 Applied Methods
 3.1 Schrödinger-Poisson Solver
 3.2 From Rates to Degradation Curves
 3.3 Density Functional Theory
 3.4 Empirical Potential Molecular Dynamics
4 Elastic Tunneling Model
 4.1 A Phenomenological Trapping Model
 4.2 Elastic Tunneling
 4.3 Conclusion
5 Level Shift Model
 5.1 Defects in Amorphous Silicon Dioxide
 5.2 The Level Shift Model
 5.3 Conclusion
6 SRH-Based Models
 6.1 McWhorter Model
 6.2 Standard Model of Kirton and Uren
 6.3 Two Stage Model
 6.4 Conclusion
7 The Extended Nonradiative Multi-Phonon Model
 7.1 Transition Rates according to the NMP Theory
 7.2 States of a Bistable Defect
 7.3 Model Evaluation
 7.4 Analytics Derivation of the Capture and Emission Time Constants
 7.5 Explanation for Noise in TDDS Measurements
 7.6 Discussion
 7.7 Conclusion
8 Conclusion and Outlook
A Physical Basics
 A.1 Fermi’s Golden Rule
 A.2 Wenzel-Kramers-Brillouin Method
 A.3 WKB Formulas for Different Shapes of Energy Barriers
 A.4 Density of States
Bibliography
Own Publications
Curriculum Vitae