Quantum interference in fully depleted tri-gate quantum-wire transistors-the role of inelastic scattering

Within the next decade, it is predicted that we will reach the limits of silicon scaling as it is currently defined. Of the new devices under investigation, one of the most promising is the tri-gate quantum-wire transistor. In this paper, we study the role quantum interference plays in the operation of this device both in the ballistic and quasi-ballistic regimes. We find that, in the ballistic case, the electrons propagating in the system tend to form vortices in their motion when subjected to moderate drain biases. These vortices form in both the source and drain of the device when the proper conditions are satisfied. Further, we observe fluctuations in the conductance of the device, which leads to fluctuations in resultant drain current due to interactions with the channel and dopant ions. When inelastic scattering is considered, the formation of the vortices is suppressed and the spread in threshold voltage fluctuations is reduced. However, the conductance fluctuations remain in the drain current once the drain voltage reaches larger values.