Self-aligned ALD AlOx T-gate footprint insulator for gate leakage current suppression in SiNx passivated AlGaN/GaN HEMTs

The devices in this study demonstrate a novel process methodology that allows for a self-aligned ALD AlO¿ gate insulator to be placed directly under the T-gate footprint and not in the access regions. After gate contact formation, standard PECVD SiN¿ passivation can be applied just as in a conventional HEMT process. Preliminary devices show promising results that this technique can be used to achieve high power mm-wave performance.