2024-03-29T15:26:39Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/298922022-11-17T02:08:08Zhdl_2115_20069hdl_2115_156Mechanism of surface conduction in the vicinity of Schottky gates on AlGaN/GaN heterostructuresKotani, JunjiTajima, MasafumiKasai, SeiyaHashizume, Tamotsu427Lateral surface leakage current (Is) on an AlGaN/GaN heterostructure was systematically investigated by using a two-parallel gate structure with a gap distance (LGG) of 200 nm–5 µm. The surface current Is systematically increased as LGG decreased. A simple resistive layer conduction that should show 1/LGG dependence failed to account for the drastic increase in Is when LGG was reduced to less than 1 µm. However, no dependence on LGG was seen in vertical current that flows in the Schottky interface. The Is showed a clear temperature dependence proportional to exp(−T −1/3), indicating two-dimensional variable-range hopping through high-density surface electronic states in AlGaN. A pronounced reduction in surface current of almost four orders of magnitude was observed in a sample with SiNx passivation. ©2007 American Institute of PhysicsAmerican Institute of PhysicsJournal Articleapplication/pdfhttp://hdl.handle.net/2115/29892https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/29892/1/APL91-09.pdf0003-69510003-6951Applied Physics Letters9190935012007-08-27enginfo:doi/10.1063/1.2775834Copyright 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.publisher