Design and Performance Analysis of Step Channel Stack Oxide DG-TFET for Dielectrically Modulated Bio-sensing Applications

In this work, a step channel stack oxide double gate (DG) TFET-based biosensor is proposed. The dielectric modulation of the device due to the presence of biomolecules is utilized for bio-sensing applications. This novel structure shows a high
$\mathrm{I}_{ON}/I_{OFF}$
ratio
$\boldsymbol{(> 10^{11})}$
, low sub-threshold slope
$\boldsymbol{(< 30\text{mV}/\text{dec})}$
and better sensitivity
$(\sim 10^{3})$
to the presence of biomolecules. The sensitivity performance of the biosensor is analyzed by varying the dielectric constant corresponding to various biomolecules and thereby calculating the sensitivity. The presence of biomolecules near the source-channel junction influences the ON current of the device leading to better device sensing capabilities. The proposed structure is simulated using commercial TCAD software (Silvaco TCAD).