A Continuous Semianalytic Current Model for DG and NW TFETs

作者：Wu Jianzhi^*; Taur Yuan

来源：IEEE Transactions on Electron Devices, 2016, 63(2): 841-847.

DOI：10.1109/TED.2015.2509468

• Ambipolar effect
• band-to-band tunneling
• scale length
• short-channel effect
• tunnel FET (TFET)

A continuous semianalytic I-V model is developed for double-gate (DG) and nanowire tunnel FETs (TFETs). At the core of the model is a gate-controlled channel potential that satisfies the source and drain boundary conditions. The band-to-band tunneling current is expressed in terms of Franz's two-band E(k) relation with 3-D density of states. Verified by numerical simulations, the model is capable of generating I-ds-V-gs characteristics for any a given bandgap and channel length, based on which the guidelines for TFET scaling are derived. A methodology for evaluating different I-ON-I-OFF characteristics, distinguished from the common practice of I-ON/I-OFF ratio and SS slope, is employed. Ambipolar effect or channel-to-drain tunneling is also covered by the model. The model has been applied to an example of GaSb-InAs DG TFET, to compare with published atomistic simulation results. I-ds-V-ds characteristics are also generated by building into the model the debiasing effect of channel charge in the linear region.

• 出版日期2016-2