Controlling the Ambipolar current by using Graded drain doped TFET

A Graded Doped Drain TFET (GD-TFET) architecture is proposed in this work to suppress the ambipolar current that exists in Conventional TFET (C-TFET). This graded doping in the drain region improves off-state parameters like off-current, ambipolar current without affecting on-state parameters. The various parameters from different TFET structures like Doping-Less TFET (DL-TFET), Low Doped TFET (LD-TFET), Conventional TFET (C-TFET), and Graded Doping TFET (GD-TFET) are simulated and compared. It has been found that the proposed architecture offers superior suppression of ambipolar current without affecting others parameters. The architecture offers an ambient current of 7×10
^-15
A/μm which is far less than the other structure of 8×10
^-10
A/μm in the case of C-TFET. The structure also offers sub-threshold swing, transconductance, and on-to-off current ratio of 35.0628 mV/decade, 1.44×10
^-05
S and 6.40×10
⁺⁰⁸
A/μm, respectively, which is comparable to C-TFET structure.