Annihilation of electrical trap effects by irradiating AlGaN/GaN HEMTs with low thermal neutrons radiation fluence

Comparison of neutron irradiation effects in AlGaN/AlN/GaN, AlGaN/GaN, and InAlN/GaN heterojunctions

“…The origin of the very high 2DEG density in III-Nitride HJs is due to the presence of both a high piezoelectric field and spontaneous polarization. 8,9 The effects of proton, [10][11][12] neutron, [13][14][15][16][17] or electron 18 irradiation manifest themselves mostly in 2DEG mobility degradation and in changes in the threshold voltage of transistor structures. 4,5 For InAlN/GaN HJs approximately lattice matched to GaN, the main contribution to the 2DEG density comes from spontaneous polarization.…”

“…4,5 The component of 2DEG density due to piezoelectric charge increases with increasing AlN mole fraction. 10 However, in the case of neutron irradiation [13][14][15][16][17] and electron irradiation, 18 the fluences leading to significant decreases in 2DEG mobility and increase of threshold voltage are too low to account for any physical mixing at the heterointerface. 6,7 The 2DEG mobility in III-Nitrides HEMTs is mainly limited by scattering due to charged ions and compositional fluctuations, with both components being strongly suppressed by the introduction of a thin AlN spacer layer.…”

Parasitic channel induced by an on-state stress in AlInN/GaN HEMTs

“…We have already shown that trapped carriers can be released from electron traps after several days. 17 In fact, this phenomenon has been observed for AlGaN/GaN HEMTs after a neutron FIG. 3.…”