Schottky Barrier FET Biosensor for Dual Polarity Detection: A Simulation Study

In this letter, we present the first tunable polarity biosensor which exhibits a high sensitivity detection capability for both negatively and positively charged biomolecules. The concept is enabled by the use of a reconfigurable transistor in which two individually gated Schottky junctions permit a selective transport of carriers through the junctions. Using TCAD simulations, we show that a threshold voltage shift of ~0.6 V and a current sensitivity >10
³
are obtained. We further demonstrate through simulations that the proposed structure enhances the sensitivity (~3 times) of the state-of-the-art Schottky FET biosensors which suffer from severely reduced transconductance due to contact passivation. With a high sensitivity and operation versatility, the proposed device holds a great promise for more compact and multiplexed sensing capabilities than the existing FET biosensors.