Proton induced trapping effect on space compatible GaN HEMTs

In order to assess the space compatibility of GaN-HEMT technology, radiation hardness tests are an essential requirement. In this field, Gallium Nitride exhibits excellent robustness with respect to radiation and GaN-based devices are providing very promising results for most of the typical space configurations. Nevertheless, in presence of very high fluence levels, displacement damage takes place reducing the device performances from the static to the dynamic point of view. This paper shows how the combination of radiation hardness tests and the improvement of deep level analysis allows us to quantify the DC and pulsed performance decrease induced by proton irradiation on a technology designed for space applications, highlighting some signatures useful for an early detection of the displacement damage. Results provide a consistent demonstration of (i) threshold voltage positive shift and (ii) trapping effect enhancement correlated with the proton irradiation fluences.