Trapping effect evaluation of gateless AlGaN/GaN heterojunctionl

摘要

An electric-field-dependent trapping effect was observed in our AlGaN/GaNntransmission-line-model u0002TLMu0003 structure. Therefore, we adopted a “gradual voltage stress” schemento induce a similar trapping effect, that is, a similar sheet resistance variation u0002u0002RSHu0003 for all intervalsnof our AlGaN/GaN TLM structure. By measuring the TLM structure under “gradual voltage stress”nu0002stressed TLM measurementu0003, we investigated the trapping effects in gateless AlGaN/GaNnheterojunction field-effect transistors. 10 nm of Al2O3 passivation film substantially decreasednthe voltage-stress-induced u0002RSH, suggesting surface traps were involved. The feasibility andnreproducibility of the stressed TLM measurement method was confirmed with repeatednpassivation. © 2010 American Institute of Physics. u0004doi:10.1063/1.3506583