6 Stacked Ge0.95Si0.05nGAAFETs without Parasitic Channels by Wet Etching

The 6 stacked Ge0.95Si0.05 nanowires without parasitic channels are realized by NH4OH + H2O2 wet etching. High ION per stack and per footprint are achieved thanks to the nanowire conduction and the electrons populated in the high mobility L4 valleys. The reduced SS of 80 mV/dec and improved ION/IOFF of 1.5E5 are obtained by the removal of parasitic channels compared to the 7 stacked Ge0.95Si0.05 nanowires with the parasitic channels in our previous work. The high ION of 120 µA per stack (4600 µA/µm per channel footprint) at VOV = VDS = 0.5 V is reached among the Ge/GeSi 3D nFETs. © 2022 IEEE.