The upgraded electrophysical and electrical models of MIS transistor sensitive elements (TSE) are presented for calculating the metrological and performance characteristics of integrated hydrogen sensors and gas-analysis microsystems based on them.

The features of the wide band gap SiC semiconductor use in the capacitive MOSFE sensors’ structure in terms of the hydrogen gas sensitivity effect, the response speed, and the measuring signals’ optimal parameters are studied. Sensors in a high-temperature ceramic housing with the Me/Ta₂O₅/SiCⁿ⁺/4H-SiC structures and two types of gas-sensitive electrodes were made: Palladium and Platinum. The effectiveness of using Platinum as an alternative to Palladium in the MOSFE-Capacitor (MOSFEC) gas sensors’ high-temperature design is evaluated. It is shown that, compared with Silicon, the use of Silicon Carbide increases the response rate, while maintaining the sensors’ high hydrogen sensitivity. The operating temperature and test signal frequency influence for measuring the sensor’s capacitance on the sensitivity to H₂ have been studied.

The technological approach for the low-scale production of field-effect gas sensors as electronic components for use in non-lab ambient environments is described. In this work, in addition to the mechanical protection of a gas-sensitive structure, an emphasis was also placed on the very topical issue of thermal stabilization around the one temperature point, even if it is several degrees higher than the surrounding one, which will probably also be useful for any type of application for many types of field-effect sensors. Considerable attention was paid to the characterization of the results obtained by various invasive and non-invasive methods for diagnosing the manufactured construction. The technology described in this article occupies an intermediate position between laboratory samples tested in clean rooms with stable ambient atmospheres, and experimental and small-scale production sensors designed for real operating conditions to solve the narrow application of measuring low concentrations of hydrogen.

We present the generalized experimental results of performance degradation of hydrogen sensors based on metal-insulator-semiconductor field effect transistor (MISFET)with the structure Pd-Ta₂O₅-SiO₂-Si. The n-channel MISFET elements were fabricated on silicon single chips together with temperature sensors and heater-resistors by means of conventional -technology. Two hundred cycles of responses to different hydrogen concentrations were measured during eight weeks using special measuring and temperature stabilization circuitries with a feedback loop based on the chip’s thermo-sensor and heater. We show how the response parameters change during long-term tests of sensors under repeated hydrogen impacts. There were two stages of time-dependent response instability, the degradation of which depends on operating conditions, hydrogen concentrations, and time. To interpret results, we proposed the models, parameters of which were calculated using experimental data. These models can be used to predict performances of MISFET-based gas analysis devices for long-term operation.

The technique of estimating the parameters models of MISTs (the field-effect transistors with metal-insulator-semiconductor structures) is proposed to predict the radiation sensitivity of the sensors