Large On-Current Enhancement in Hetero-Junction Tunnel-FETs via Molar Fraction Grading

We propose to employ a grading of the molar fraction in the source region of III–V hetero-junction tunnel- FETs as a means to improve the ON-current without degrading the subthreshold swing. Our full quantum simulations show that the molar-fraction grading increases the ON-current by enlarging the hole wave function penetration from the source to the channel region.We also compare the performance of graded AlGaSb/InAs tunnel FETs and InAs MOSFETs and show that at VDS = 0.3 V, the tunnel device can outperform the MOSFET in terms of both ON-current and subthreshold slope.