DOI
https://doi.org/10.25772/3RDH-5G14
Defense Date
2015
Document Type
Thesis
Degree Name
Master of Science
Department
Physics and Applied Physics
First Advisor
Michael A. Reshchikov
Abstract
There is an understanding of surface photovoltage (SPV) behavior for GaN, yet little is known about the SPV behavior for AlGaN. In this work, a Kelvin probe was used to measure the SPV for p-type AlGaN. Very slow SPV transients were found in AlGaN, which could not be explained with a simple thermionic model. A possible explanation of this behavior is the segregation of impurities to the surface, which causes significant reduction of the depletion region width (down to 2 nm), with carrier tunneling and hopping becoming the dominant mechanisms responsible for the SPV transients. To verify this assumption, the near-surface defective region (about 40 nm) has been removed through the ICP-RIE process. After the etching, the SPV transients became fast and increased in magnitude by about 0.6 eV. By using the thermionic model, band bending was estimated to be -1 eV.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
5-8-2015