Abstract
The present work reports on a distinct and very reproducible bistable-like behavior of two defects at around EC − 0.5 eV in MOCVD-grown GaN. The kinetics of the thermally activated transformation between the two states are analyzed in an Arrhenius model, yielding an energy barrier of 0.4 ± 0.1 eV, and a frequency factor of 106±1 s−1. Depth profiles suggest that the charge state of the defects determines the observed amplitude variation. Relevant models for the observed behavior, and their shortcomings are discussed: (i) passivating properties of hydrogen, and (ii) bistable defect component(s). A proper explanation of the experimental observations represents, however, a further challenge.
Highlights
The understanding of the electronic properties of defects in epitaxial GaN is an essential part of defect engineering for the use of GaN in opto, RF, and power electronics
Interpreting bi- or multistable behavior of electrically active defects expands the understanding of their atomic structure and possible configurations
Five defect levels are observed in the metal-organic chemical vapor deposition (MOCVD)-grown GaN layers within the investigated temperature region
Summary
The understanding of the electronic properties of defects in epitaxial GaN is an essential part of defect engineering for the use of GaN in opto-, RF-, and power electronics. In spite of considerable research efforts for the last two decades, directed towards defect identification, there are still big gaps in our understanding of their properties. To our knowledge, only a few reports on electrically metastable defect states in GaN have so far been published, and a major part of them concerns externally induced damage (by e.g. ion implantation, thermal stress, sputter deposition of the Schottky contact, and plasma treatment prior to the Schottky contact deposition). A couple of references report and analyze bistable-like behavior in as-grown GaN; an example is the DLTS line at ∼EC − 0.6 eV, with a speculative hypothesis of hydrogen passivation that, was not demonstrated experimentally
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
