Sensitivity Measurement for Bio-TFET Considering Repulsive Steric Effects With Better Accuracy

Abstract

Sensitivity analysis of label free Bio-TFET considering repulsive steric effects (RSEs) has been addressed in the paper. Doping-less underlap dielectric modulating tunnel field effect transistor (DU-DM-TFET) is assumed like a reference structure. Initially, the efficacy of doping-less underlap (DU) TFET without cavity has been compared with the reported TFET literatures. Later, the impact on surface potential (ψ), energy band (EB), ON-current (I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> ), I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</sub> /I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OFF</sub> ratio, sub-threshold swing (SS), and their corresponding sensitivity due to variations of permittivity (k) along with charge density (N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</sub> ) of bioanalytes, length of cavity (L <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cavity</sub> ) and cavity thickness (T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cavity</sub> ) have been addressed in this context. Non-uniform patterns of bioanalytes inside the nanogap cavity regions considering impulsive steric effects make the analysis more practical. Later, an assessment of noise features inside the cavity of DU-DM-TFET based biosensor is explored. Finally, an error assessment table is prepared to evaluate sensitivity errors (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E</sub> ) in the reported literature using the proposed RSE. A maximum 40% error in effective capacitance has been found if RSE is not considered. So, RSEs need to be considered always during the analysis of label free biosensing.