High-energy proton radiation effect of Gallium nitride power device with enhanced Cascode structure br

To ascertain the damage mechanism caused by high-energy proton irradiation to AlGaN/GaN powerdevices of enhanced Cascode structures, we study the radiation effect of enhanced Cascode structure anddepletion AlGaN/GaN power devices by using 60 MeV energy protons in this work. In the case of protoninjection reaching 1x1012 p/cm2, the experimental results show that the threshold voltage of the Cascode typedevice is negatively drifted, the transconductance decreases, and the peak leakage current increases. Thethreshold voltage decreases from 4.2 V to 3.0 V, with a decrement of 1.2 V, and the peak transconductancevalue decreases from 0.324 S/mm to 0.260 S/mm, with a decrement of about 19.75%. There is no significantchange after the conventional depleted AlGaN/GaN device has been irradiated. The Cascode-type AlGaN/GaNpower device is more sensitive to proton irradiation than the depletion-type AlGaN/GaN device. The Cascode-type device is sensitive to proton irradiation because of its structure connected to a silicon-based MOS tube.Proton irradiation causes the silicon-based MOS gate oxide layer to generate a large amount of net positivecharge, induces an ionization damage effect, and causes threshold voltage to negatively drift and the gateleakage current to increase. The equivalent 60 MeV energy protons and cumulative injection of 1x1012 p/cm2dose of the radiation device is used to obtain the ionization damage effect. It is found that after beingirradiated by the equivalent dose ray , the device has the threshold voltage decreasing from 4.15 V to2.15 V, with a negative drift of 2 V; transconductance peak decreases from 0.335 S/mm to 0.300 S/mm, with anapproximate decrement of 10.45%. The degradation of the electrical properties of the device after beingirradiated by ray is consistent with the degradation law after being irradiated by high-energy protons. Inorder to further verify the experimental accuracy and conclusions, the ionization energy loss and non-ionizationenergy loss induced by radiation in the device are obtained by Monte Carlo simulation. The simulation resultsshow that the ionization energy loss induces silicon-based MOS to generate oxide trap charge and interfacialstate trap charge, which is mainly responsible for the performance degradation of AlGaN/GaN HEMT power devices with enhanced Cascode structure.