On the features of hydrogen detection by a semiconductor structure grown on a 6H-SiC substrate by the combined method of platinum ion implantation and deposition

The results of a comparative study of the electrical properties of gas-sensitive semiconductor structures grown by the pulsed laser deposition of platinum, platinum ion implantation, and a combined method of platinum implantation and deposition onto an $n$-6H-SiC substrate are presented. Double-layer structures show a stronger response to hydrogen gas with a more pronounced diode behavior of the currentvoltage characteristics at high temperatures of $\sim$ 500$^\circ$C than single-layer ion-implanted structures. Furthermore, double-layer structures exhibit higher reproducibility of the current-voltage characteristic parameters during thermal cycling in a hydrogen-containing medium than ordinary thin-film structures on SiC substrates. The chemical state of ion-implanted platinum and the structure of thin-film layers after long-term testing are studied under harsh conditions. Possible mechanisms of the effect of platinum on the current flow in the ion-implanted layer and its dependence on the composition of the surrounding gaseous medium are considered.