Tunneling FET With Embedded P+ Pocket as a High Sensitivity Biosensor for Label-Free Detection

In this paper, an efficient structure for tunneling field effect transistors (TFETs) with P+ pocket is proposed for label-free detection of biomolecules. This structure includes a double gate TFET with P+P-N+ doping profile for source, channel, and drain regions and an embedded P+ pocket in the channel to control the band-to-band tunneling (BTBT). The biomolecules are captured in the cavity region and affect the band bending. The capacitive behavior of biomolecules causes further band bending where their dielectric constant is increased. The presence of P+ pocket at the source side of TFET causes more changes in the capacitive behavior and in current and consequently increases the sensitivity. For the detection of the biomolecule with K=۴, the proposed structure shows more than ۶۰% improvement in sensitivity. It enhances the sensitivity for all investigated dielectric constants, where the enhancement is more considerable for biomolecules with higher dielectric constants. For more evaluation, the biosensor is assessed in different widths and impurity densities of P+ region. It demonstrates that the proposed structure can efficiently tolerate the variations in physical dimension and impurity concentration while it maintains higher sensitivities.

کلیدواژه ها:

Tunneling FET ، Biomolecule ، Sensitivity ، band-to-band tunneling ، Band Bending