关键词: AlGaN/GaN HEMT, 质子辐照, 辐射感生受主缺陷, 辐射加固

Abstract:

The radiation effect of FP-GaN HEMT was investigated by using proton radiation source.After low irradiation fluence, the phenomena of an increase in carrier density of GaN material was found.The device showed negligible degradation at low proton fluences.At high fluences, the decreased drain current and transconductance as well as the obviously shifted threshold voltage of HEMT were observed.And the ohmic contact was so relative robustness to proton, but the Schottky characteristics degraded obviously.Utilizing the depletion approximation theory and the introduction of acceptor defects to express radiation induced defects in AlGaN/GaN heterostructures, we developed irradiation induced acceptor defects damage model for AlGaN/GaN HEMT.The simulations indicated that the acceptor defects induced in both channel and buffer layer dominate the radiation damage in AlGaN/GaN HEMT.A good agreement between calculations and experiments presents the validity of this model.The annealing results proved that the damage induced by proton may be partially recovered.SiN-passivated FP-AlGaN/GaN HEMTs appear to be attractive candidates for space and terrestrial applications, and the HEMTs are resistant to displacement damage.

Key words: AlGaN/GaN HEMT, proton-irradiation, irradiation induced acceptor defects, radiation hardness