Improvement of interface properties of AlGaN/GaN heterostructures under gamma-radiation

Electrical characterization of 60Co gamma radiation-exposed InAlN/GaN high electron mobility transistors

“…Most of the radiation studies involving GaN-based HEMTs have involved proton or electron damage. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] In terms of heterostructures, preliminary data from proton damage studies suggests that the radiation hardness decreases in the order AlN/GaN > AlGaN/GaN > InAlN/GaN, consistent with the average bond strengths in the Al-based materials. 13 The effects of gamma-ray irradiation are also of fundamental interest for space applications and electronics in nuclear plants.…”

“…[14][15][16][17][18][19] In general, these devices exhibit negative threshold voltage shifts and in some cases an increase in 2DEG sheet concentration, in contrast to the results for proton-irradiated HEMTs. [14][15][16][17][18][19] Some of the important factors that could affect the electrical characteristics after the gamma-ray irradiations include the presence of a passivation layer, the metals used in the gate and Ohmic contacts, the native defect density in the barrier and GaN layers, and the gate length and gate width. 19 The passivation layer affects the transport in the channel in HEMTs and can reduce current fluctuations after irradiation.…”

“…Gamma rays can cause reactions at the interface between the metal and semiconductor, resulting in high ideality factors and increased on-state resistance, 21 as well as reordering of native defects and impurities. 16,22 Devices with small gate lengths and widths are vulnerable to radiation because of the larger relative decrease in effective carrier density. 21 In this study, we report the changes in DC characteristics of In 0.17 Al 0.83 N/GaN HEMTs after cumulative 60 Co gammaray irradiation from 30 to 500 Mrad.…”

“…In addition, the metallization was the same for all devices after gamma-ray irradiation, which is consistent with the previous results. [14][15][16]19,24 Since the a) Electronic mail: hyunhyun7@korea.ac.kr critical factor that affects radiation resistance is the effect of radiation-induced defects on the electrical performance of devices, we focused on the DC characteristics of the InAlN/ GaN HEMTs in our experiments.…”

Review of radiation damage in GaN-based materials and devices

“…However, as with MOCVD, the introduction rates of all traps were several times lower than the electron removal rate, again suggesting the dominant role of DRs in carrier removal. For ELOG material, considerable broadening of x-ray rocking curves for the (0006) symmetric reflection and (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) asymmetric reflection occurred as a result of neutron fluence irradiation of 10 18 cm À2 . This broadening indicates an increased density of extended defects, confirmed by etch pit density (EPD) measurements that show an increase by about 5 Â 10 7 cm À2 in the high dislocation density regions and the appearance of new irradiation induced inclined dislocation bands in the low dislocation density wings.…”