Direct Measurement of Carrier Mobility in Intrinsic Channel Tri-Gate Single Silicon Nanowire Metal-Oxide-Semiconductor Field-Effect Transistors

In this paper, we report the direct measurement of intrinsic carrier mobility in "single"-silicon-nanowire metal-oxide-semiconductor field-effect transistors (MOSFETs) for the first time. To obtain intrinsic carrier mobility with high accuracy by the split capacitance-voltage (C-V) method, ultralong single-silicon-nanowires, instead of multiple parallel nanowires, were designed and fabricated. The open-circuit method was utilized to remove the parasitic effect in measured capacitance. It is found that, although mobility degradations in narrower nanowires are seen in both electrons and holes, the hole mobility is higher than the universal mobility on the (100) surface even in a "single"-nanowire thanks to the high hole mobility on the (110)-oriented side surface of the [110]-directed nanowire. The extracted mobility indicates that surface orientation plays a key role in nanowire mobility. (C) 2013 The Japan Society of Applied Physics