Unveiling the Self-Heating and Process Variation Reliability of a Junctionless FinFET-Based Hydrogen Gas Sensor

Field-effect-transistor-based sensors are essential for environmental monitoring, industrial analyte detection, medical diagnosis, etc. This letter unveiled the process variation, self-heating-induced performance barrier, and aging issues of the junctionless (JL) FinFET-based hydrogen (H2) gas sensor. Using Sentaurus technology computer-aided design (TCAD), following gate work function modulation owing to H2 gas concentration (in ppm), we analyzed 1) the impact of the self-heating effect (SHE) on sensing characteristics; 2) the impact of different metal grain sizes on work function variation (WFV); 3) impact of random dopant fluctuation (RDF); and 4) device's end-of-lifetime (EOL) to predict the aging. As proof of concept, the JL device was fabricated and found to sense hydrogen with a response of (23.59 ± 1.2)% for 1.0 ppm of the gas, which agrees with our simulation results. The observed threshold voltage sensitivity is a maximum of ∼124.43% for 1.02 ppm. Thus, the proposed analysis would provide a deeper insight into a FinFET-based H2 gas sensor from a reliability perspective.