High transconductance surface channel In0.53Ga0.47As MOSFETs using MBE source-drain regrowth and surface digital etching

Abstract

We demonstrate In_0.53Ga_0.47As surface channel MOSFETs using a gate-last process and MBE source/drain (S/D) regrowth. The structure uses a sacrificial N+ InGaAs channel cap layer between the regrown S/D contact layer and the channel, which is removed in the channel region by a “digital” etch process incorporating UV ozone oxidation and surface stripping in dilute HCl. A device with 65 nm-L_g and 1.2 nm EOT shows 1.6 mS/μm peak transconductance at V_ds = 0.5 V and 120 mV/dec SS at V_ds = 0.05 V, while 535 nm-L_g devices show 95 mV/dec SS at at V_ds = 0.1 V.