Numerical simulation of dielectrically modulated junctionless accumulation mode FinFET for biomolecule detection

Abstract

This work investigates the detection of biomolecules using a junctionless accumulation mode Fin-type field-effect transistor (FinFET) as a dielectric modulated biosensor for medical diagnostics and food analysis applications. This study focuses on detecting neutral biomolecules, namely Keratin, Zein, Aminopropyltriethoxysilane (APTES), Biotin, and Streptavidin. Sentaurus technology design (TCAD) simulator is used in this work for the simulations. The variation in different electrical parameters of the device, namely switching ratio (I_ON/I_OFF), transconductance (g_m), and threshold voltage (V_th), is observed when neutral biomolecules are introduced inside the cavity with respect to their dielectric properties. The device's performance is analyzed by varying its parameters, including cavity thickness, cavity length, fin height/width, and doping concentration in the channel, as well as source/drain regions. The results are then compared with those of an under-gate dielectric modulated junctionless fin-type field-effect transistor having similar dimensions, and it is noticed that a significant improvement in biosensing is achieved by moving to a junctionless accumulation mode FinFET biosensor.