Impact of drain doping engineering on ambipolar and high-frequency performance of ZHP line-TFET
Sasmita Sahoo, Sidhartha Dash, Soumyaranjan Routray, Guru Prasad Mishra
Abstract
Abstract In this paper, we present a new Z-shaped line tunnel field effect transistor (TFET) employing drain doping engineering with a split drain structure (SD-ZHP-TFET). The split drain (SD) approach in the proposed ZHP-TFET helps increasing tunneling width at the channel-drain interface, reducing ambipolarity. Moreover, a horizontal pocket (HP) is implanted in the source region to boost the ON-current of the proposed SD-ZHP-TFET structure. The effect of both these approaches in the line-TFET provides higher ON-current and reduces ambipolarity significantly. Split drain structure in the ZHP-TFET exhibits a three-decade improvement in the ambipolar current without affecting the subthreshold (SS) and leakage current significantly. A calibrated simulation study of split drain thickness (t u ) and drain region doping variation on the analog performance are investigated using the technology computer-aided design device simulator. Moreover, the high-frequency figure of merit regarding total gate capacitance (C gg ), unit-gain cut-off frequency (f T ) is analysed. It is found that the drain doping improves the cut-off frequency from 1.8 GHz in ZHP-TFET to 2.2 GHz in the proposed SD-ZHP-TFET structure. Thus the proposed device is capable of providing higher I ON /I OFF (≈10 13 ) and I ON /I AMB (≈10 13 ) ratio with an average SS of 44 mV/decade.