Scaling Length Theory of Double-Gate Interband Tunnel Field-Effect Transistors

A scaling theory of double-gate interband tunnel field-effect transistors (TFETs) using a physics-based 2-D analytical model is presented. Ignoring the mobile charge in the channel, the electrostatic potential profile and electric field are analytically solved, and the current is calculated by integrating the band-to-band tunneling generation rate over the volume of the device. The analytical model has excellent agreement with the numerical results obtained from a commercial simulator and atomistic nonequilibrium Green function simulations for both heterojunction and homojunction TFETs. The analytical model allows us to quantitatively extract the electrostatic scaling lengths in TFETs and compare the short-channel effect of TFETs with that of MOSFETs. We conclude that double-gate TFETs exhibit superior short-channel performance than their MOSFETs counterparts at a longer gate length (greater than four times the scaling length), but the scalability of the TFETs degrades at a faster rate than MOSFETs do at smaller gate lengths (less than four times the scaling length).