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.

A prototype of a nitro compound vapor and trace detector, which uses the pyrolysis method and a capacitive gas sensor based on the metal–insulator–semiconductor (MIS) structure type Pd–SiO₂–Si, was developed and manufactured. It was experimentally established that the detection limit of trinitrotoluene trace for the detector prototype is 1 × 10⁻⁹ g, which corresponds to concentration from 10⁻¹¹ g/cm³ to 10⁻¹² g/cm³. The prototype had a response time of no more than 30 s. The possibility of further improving the characteristics of the prototype detector by reducing the overall dimensions and increasing the sensitivity of the MIS sensors is shown.

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.

A simple method is demonstrated for hydrogen concentrations measurement directly in transformer oil and in the gas space above it use a highly sensitive (at the level of units and fractions of ppm) gas sensor based on a metal-insulator-semiconductor capacitive structure (MIS sensor). The results obtained can be used in online monitoring systems and predicting the power transformers integral performance, in particular those that have been put into operation long ago, by tracking slow and invisible at the initial stage aging processes of current-carrying connections and structural elements.

The article describes the result of the use SnO₂-Pd thin films as a gate for structure measured ppb range of NO₂ gas by the capacitive method. The technological aspects of fabrication SnO₂-Pd gate and one comparison by metrological parameters with the classical Pd gate field effect sensor are discussed. The use of SnO₂-Pd material allows improvement in sensitivity of NO₂ by an order of magnitude compare the classical Pd based gate field effect sensors.