N+ Pocket Doped Vertical TFET Based Dielectric-Modulated Biosensor Considering Non-Ideal Hybridization Issue: A Simulation Study
Vandana Devi Wangkheirakpam, Brinda Bhowmick, Puspa Devi Pukhrambam
Abstract
A comprehensive evaluation of sensitivity between double gate tunnel FET and n+ pocket doped vertical tunnel FET based label-free biosensors is reported in this work. Both the biosensors possess nanogaps on the left and right of the fixed dielectric (HfO2) which enhances the capture area of the biosensors. Comparison has been made on the TCAD simulation studies of their sensitivities considering neutral/charged biomolecules having different dielectric constants. The sensitivity of VB is found to be approximately 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> times the sensitivity of DB due to its current conduction in both vertical and lateral directions. Also, the effects of steric hindrance and irregular position of probes/receptors are analyzed to understand the non-ideal behavior of the sensors. Sensitivity is calculated from the simulated results for four different cases of partially filled nanogaps - decreasing, increasing, concave and convex profiles. It rises by about 5-7% when filled factor is increased from 40 to 66%. Finally, benchmarking of proposed VB is done against other published literature as it gives better result in terms of sensitivity.