Impact of Gamma Radiation on Dynamic RDSON Characteristics in AlGaN/GaN Power HEMTs

Abstract

GaN high-electron-mobility transistors (HEMTs) are promising next-generation devices in the power electronics field which can coexist with silicon semiconductors, mainly in some radiation-intensive environments, such as power space converters, where high frequencies and voltages are also needed. Its wide band gap (WBG), large breakdown electric field, and thermal stability improve actual silicon performances. However, at the moment, GaN HEMT technology suffers from some reliability issues, one of the more relevant of which is the dynamic on-state resistance (RON_dyn) regarding power switching converter applications. In this study, we focused on the drain-to-source on-resistance (RDSON) characteristics under 60Co gamma radiation of two different commercial power GaN HEMT structures. Different bias conditions were applied to both structures during irradiation and some static measurements, such as threshold voltage and leakage currents, were performed. Additionally, dynamic resistance was measured to obtain practical information about device trapping under radiation during switching mode, and how trapping in the device is affected by gamma radiation. The experimental results showed a high dependence on the HEMT structure and the bias condition applied during irradiation. Specifically, a free current collapse structure showed great stability until 3.7 Mrad(Si), unlike the other structure tested, which showed high degradation of the parameters measured. The changes were demonstrated to be due to trapping effects generated or enhanced by gamma radiation. These new results obtained about RON_dyn will help elucidate trap behaviors in switching transistors.

Neutron Irradiation of AlGaN Polarization Doped Field Effect Transistors

“…unintentional gamma radiation association is not expected to have any effect at an expected dose of < 10 2 rad based on previous literature of wide bandgap semiconductors. 6,[20][21][22]…”

Interplay Between γ–Ray Irradiation and 3DEG for Dosimeter Applications

“…This has a direct consequence in establishing a charge transfer in accordance with the trap assisted tunnelling (TAT). The TAT is dictated by the evolution of radiation induced traps that favor hole trapping due to a reduction in the barrier height [28][29][30][31][32][49] [53][54]. It effectively reduces the channel depletion as observed under the Source electrode at GaN top and graded AlGaN layers.…”

“…As a consequence, the operating conditions of the dosimeter remains intact. In addition, experimental reports [54][55] suggest the recovery of such irradiated samples post high temperature annealing process, which adds up to the stability of the DUT for dosimetry applications.…”

Heavy ion irradiation induced failure of gallium nitride high electron mobility transistors: effects of in-situ biasing

“…Gold heavy ions with mid-level energy (1.5 MeV) and 6.5 × 10 15 gold cm −2 fluence are shown to generate defect clusters that decrease saturation current by four orders of magnitude and cause loss of gate control [12]. Some studies claimed that the presence of an electric field has no impact on incoming ion radiation [19], whereas others show dissimilar behavior in transport properties between ON and OFF conditions [20][21][22][23][24]. Ionizing sources, such as X-ray and 60 Co, have been employed to evaluate the influence of irradiation at various bias conditions in HEMTs.…”