Characteristic enhancement in tunnel field-effect transistors via introduction of vertical graded source

A novel vertical graded source tunnel field-effect transistor(VGS-TFET)is proposed to improve device performance.By introducing a source with linearly graded component,the on-state current increases by more than two decades higher than that of the conventional GaAs TFETs without sacrificing the subthreshold swing(SS)due to the improved band-to-band tunneling efficiency.Compared with the conventional TFETs,much larger drive current range can be achieved by the proposed VGS-TFET with SS below the thermionic limitation of 60 mV/dec.Furthermore,the minimum SS about 20 mV/dec indicates its promising potential for further ultralow power applications.