A Charge Plasma Based Label Free Biomolecule Detector Using SiGe-Heterojunction Double Gate Tunnel FET

Abstract

To overcome the random dopant fluctuations (RDFs) and high thermal budget problems faced by normally doped Tunnel Field Effect Transistor (TFET) devices, charge plasma SiGe-heterojunction double gate TFET is utilized to design a label free biosensor. The performance of proposed biosensor is analyzed for different values of dielectric constant (k), charge density (both positive and negative), gate work function and cavity dimensions. These parameters alter the electric properties of the biosensor which help in the detection process. Their effect on the drain current, electric field, surface potential, sub-threshold swing (SS), ION/IOFF ratio, and electron tunneling rate (ETR) of the device is also discussed. Furthermore, the drain current sensitivity of the proposed biosensor is analyzed and it is found that a maximum sensitivity of 1.13 × 1010 is obtained for dielectric constant k = 12. The proposed biosensor is implemented by carrying out two-dimensional device simulations using the Silvaco ATLAS tool.