Low-Temperature Transport Characteristics and Quantum-Confinement Effects in Gate-All-Around Si-Nanowire N-MOSFET

Gate-all-around n-MOSFETs with Si-nanowire (~7 nm) as the channel body are fabricated and characterized for their low-temperature behavior (~5 K to 295 K). I_DS-V_GS characteristics at low V_DS (~50 mV) exhibit a decrease in current with decreasing temperature in strong inversion up to about ~200 K. However, at high V_DS, drain current reverts to typical temperature behavior, i.e., I_DS increases with the reducing temperature due to the increase in phonon-limited mobility (mu_ph)- It is inferred that, at low V_DS the enhancement in mu_ph at a reduced temperature could be possibly masked by the intersubband scattering on account of subband splitting due to quantum-confinement effects as indicated by subband calculations for nanowire structures.