AlGaN/GaN MIS-HFET with improvement in high temperature gate bias stress-induced reliability

CMOS-compatible GaN-on-silicon technology with excellent D-mode MISHFET performance is realized. A low specific contact resistance R_c (0.35 Ω-mm) is achieved by Au-free process. MIS-HFET with a gate-drain distance (L_GD) of 15 μm exhibits a large breakdown voltage (BV) (980 V with grounded substrate) and a low specific on-resistance (R _ON,_sp) (1.45 mΩ-cm²). The importance of epitaxial quality in a key industrial qualification item: high temperature gate bias (HTGB) stress-induced voltage instability issue is figured out and a breakthrough by optimizing GaN epitaxial layer for improvement of MIS-HFET is demonstrated. A low V_th shift of the optimized MIS-HFET is achieved ~ 0.14V with qualification stress condition V_G of -15 V at ambient temperature of 150 oC for 128 hours.