Authors: Y. Song, Y. Guan, J. Zhang, J. He, X. Zhang, X. Lin
Affilation: Peking University, China
Pages: 717 - 720
Keywords: device physics, modeling, bio-FET, pH sensor
In this paper, the analytic modeling of the BioFET as a pH sensor has been developed from the complete surface potential equation and channel expression. Combining the physical MOSFET theory with electrochemistry of the electrolyte, the expressions of both the potential drop in the electrolyte and the surface potential of the substrate are obtained, respectively, by using an analytic approximation. The drain current and signal noise ratio (SNR) variations with different values of the electrolyte are also discussed for different electrolyte, providing an order condition to gain preferable performance. The modeling results are also verified by the numerical simulation, proving the model validity.