Development and investigation of DMDG-MOSFET biosensor for charged biomolecule detection

The paper explores the analog and sensitivity parameter of a n-channel gate stack Dual Material Double Gate (DMDG) MOSFET biosensor, specifically focusing on its response to a wide range of charged biomolecule introduced into its cavity region. This novel structure offers improved sensitivity and selectivity due to its ability to modulate the threshold voltage and control the electrostatic environment more precisely compared to conventional MOSFET-based biosensors. The analysis includes a thorough examination of the surface potential, electric field, transconductance, and threshold voltage variations influenced by the presence of charged biomolecules. By applying a parabolic-potential technique to solve the 2D Poisson’s equation, the expression for surface potential can be found. The minimal surface potential model is used to calculate the threshold voltage. Using SILVACO ATLAS, the simulation findings suggest that the proposed gate stack DMDG-MOSFET structure demonstrates sensitivity of 0.123 V and 0.607 V for neutral and charged biomolecules respectively emphasizing the impact of gate material engineering on the biosensor’s performance.