N-polar GaN-based highly scaled self-aligned MIS-HEMTs with state-of-the-art fT.LG product of 16.8 GHz-µm

In this paper, we describe a gate-first self-aligned MBE InGaN regrowth methodology for fabricating N-polar GaNbased MIS-HEMTs which exhibit ultra-low contact resistances of 23 Ω-μm, which is comparable to the lower band-gap technologies. These devices, not only show state-ofthe-art f_T.-L_G product values of 16.8 GHz-μm for 130 nm gatelength for GaN, but also show exceptional performance at low supply voltages (VDs = 500 mV), thereby making GaN competitive not only to wide band-gap materials like SiC but also to low band-gap technologies by InGaAs HEMTs and InSb by having low knee voltages, high drive currents while still demonstrating relatively large breakdown voltages for unipolar (non-CMOS like) operation.