Comparison of Proton Irradiation Effects on Electrical Properties of Quasi-Vertical and Lateral GaN Schottky Barrier Diodes

In this article, quasi-vertical and lateral gallium nitride (GaN) Schottky barrier diodes (SBDs) with similar electrical parameters are irradiated with 200-keV protons at different fluences. The radiation-induced defects induced by irradiation affect carrier concentration and tunneling current, result in a slight decrease in the forward current and an increase in the reverse current of quasi-vertical GaN SBDs. In contrast, lateral GaN SBDs exhibit significant degradation in forward current characteristics and a reduction in reverse current postirradiation. Electrical parameter variations in the N<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-}$ </tex-math></inline-formula>-GaN and N+-GaN layers of quasi-vertical SBDs, as well as changes in 2-D electron gas (2DEG) concentration at the AlGaN/GaN heterojunction interface in lateral diodes, are analyzed through C–V, transmission line model (TLM), and Hall measurement. By combining stopping and range of Ions in matter (SRIM) and technology computer-aided design (TCAD) simulations, the types and distributions of radiation-induced defects in both GaN SBDs are modeled to comprehensively reveal the degradation mechanisms in both devices under proton irradiation.