Sensitivity Analysis of T‐Shaped Source Tunneling Field‐Effect Transistor Biosensor With N ⁺ Pocket Layer and Insulated Pocket Layer

This work presents a biosensor based on T‐shaped source tunneling field‐effect transistor biosensor with N ⁺ pocket layer and insulated pocket layer (IP‐P‐T‐TFET). The insulated pocket layer is used to increase the drain current sensitivity of the IP‐P‐T‐TFET biosensor through decreasing the drain current of the biosensor when it is filled with air. In addition, the subthreshold swing (SS) of the IP‐P‐T‐TFET is also improved owing to the fact that the insulated pocket layer mitigates the source‐corner effect which exists in extended‐source TFET and deteriorates the SS of the device. What is more, using the N ⁺ pocket layer leads to decreased tunneling distance and increased sensitivity in comparison with a conventional T‐shaped source TFET (T‐TFET) biosensor. For K  = 10, S _{I on} =  8.72 × 10 ⁹ , S _{I on/ I off}  = 1.8 × 10 ⁹ , and S _{G m} = 2.37 × 10 ⁹ . The effect of charged biomolecules on the sensitivity performance is examined. Finally, the effect of various fill factors on the sensitivity characteristic is discussed. The results show the IP‐P‐T‐TFET biosensor can still achieve a relatively higher I _on sensitivity at lower fill factors.