Origins of Performance Enhancement in Independent Double-Gated Poly-Si Nanowire Devices

In this paper, we characterize and compare the characteristics of a poly-Si nanowire (NW) device with independent double-gated configuration under different operation modes. In the device, the tiny NW channels are surrounded by an inverted-T-shaped gate and a top gate. It is found that the device under double-gate (DG) mode exhibits significantly better performance with respect to the two single-gate (SG) modes, as indicated by a higher current drive than the combined sum of the two SG modes and a smaller subthreshold swing of less than 100 mV/dec. Origins of such improvement have been identified to be due to the elimination of the back-gate effect as well as an enhancement in the effective mobility with the DG operation.