Enhancement-mode AlGaN/GaN with plasma oxidation technology

High performance millimeter-wave enhancement-mode AlGaN/GaN HEMTs using plasma oxidation technology (POT) is fabricated by PECVD. The PECVD system avoids downward bombardment making this process damage free. The POT enables the formation of a thin oxide layer on gate region, ultralow leakage was achieved on the fabricated device, Ioff = 9.5× 10−7 mA/mm and it has a high ON/OFF ratio of over 109, the lowest off-state leakage for the AlGaN/GaN in deep-submicrometer gate length. The enhancement-mode AlGaN/GaN HEMTs using this new oxidation technology exhibits outstanding performance including Vth of 0.4 V, maximum drain current of 1 A/mm and fmax of 170 GHz.