|M.Sc Student||Osman Bilal|
|Subject||Study of Electron Trapping Effects in Gallium Nitride|
|Department||Department of Electrical Engineering||Supervisor||Professor Dan Ritter|
|Full Thesis text - in Hebrew|
Wide gap semiconductors such as SiC and GaN are an attractive replacement of silicon in the microelectronics industry for high power applications due to their high bandgap voltage and high electron mobility. A major concern in the case of the GaN technology is electron traps, which degrade device performance.
This work focuses on the evaluation of the trap density in an AlGaN\GaN structure using the gated van der Pauw method. The electron concentration in the channel of the device was measured as a function of voltage and time, and the trap concentration was extracted from the data. We have found that the trap concentration at the interface to the dielectric passivation layer, as well as in the AlGaN barrier layer, is much lower than previously expected. It thus appears that most of the trapping in the transistor takes place in the GaN buffer layer.
To makes sure that all traps are accessible during the measurement, we have also used UV radiation the create electron hole pairs. Trapped electrons should recombine with the holes. In this work, only initial data on the effect of UV radiation was obtained. This study will be continued in future research.