Gate-on-drain overlapped L-shaped channel Tunnel FET as label-free biosensor

In this manuscript gate-on-drain L-shaped channel Tunnel FET is proposed to detect various biomolecules through label-free bio-sensing detection technique. Biomolecules can be detected in the proposed structure through modulating ambipolar current between channel and drain by overlapping gate on drain thus creating a cavity. Trapped biomolecules within cavity gets immobilized. Immobilized biomolecules change the drain to channel tunneling width, thus changing the ambiploar leakage current. Drain doping and cavity length was fine-tuned to achieve better sensitivity in terms of ambipolar current and ambipolar knee voltage shift with and without presence of biomolecules. A maximum sensitivity of 3.8×107 is achieved for drain doping of 5×1019 donors/cm3 and cavity length of 60nm. A high value of sensitivity is achieved for each biomolecules when drain doping ranged from 1019 donors/cm3 to 5×1019 donors/cm3 and cavity length ranged between 40nm to 50nm. Effect of differently charged biomolecules on sensitivity has also be structured.