Modeling and virtual fabrication of conducting polymer gate Junctionless FinFET based poisonous gas detector

Direct electrical measurements, which track variations in intrinsic electrical characteristics of the FETs have led to exponential growth in development of solid-state sensors over past few decades. Further, FET-based sensing systems drastically reduce cost, have high sensitivity, provide fast response time, have low power consumption and are compatible with CMOS technology. Hence, in this work poisonous gas sensor has been designed for detection of gases-hexane, chloroform, dichloromethane, iso-propanol and methanol using Junctionless FinFET which utilizes conducting polymer (CP) Poly(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene)/Perchlorate/Acetonitrile (PPP-ClO4/AcCN) as gate material. Work function modulation of CP gate is investigated for variation in electrical parameters of the device upon exposure to various poisonous gases. The calibration of the JL FinFET is performed with previously reported experimental data. An analytical model has been developed for the proposed gas sensor and results are verified by TCAD simulation. The performance of the sensor has been analyzed by evaluating-Surface potential $${(S}_{msp}$$ ) and Threshold voltage sensitivity $$({S}_{Vth})$$ . $${S}_{Vth}$$ obtained for the gas sensor for detection of dichloromethane, iso-propanol and methanol is higher by 12.5%, 45% and 87% as compared to Svth obtained for previously reported FET gas detectors. JL FinFET poisonous gas detector also shows higher drain current senstivity of 97% when compared with CNT FET for detection of methanol gas. Virtual fabrication of the gas sensor is carried out on TCAD Sentaurus. The reliability analysis is also carried out by exposing gas sensor to high temperature to predict its performance at elevated temperature and is found to work efficiently upto 550 K.