Ion implantation of platinum from pulsed laser plasma for fabrication of a hydrogen detector based on an n-6H-SiC crystal

Abstract

A fairly simple method of surface doping of a SiC substrate with a catalytic metal (in particular, platinum) from a pulsed laser plasma is suggested. Doping is attained due to implantation of high-energy ions and ion mixing of the plasma-deposited film with the surface layer of the SiC substrate. The developed mathematical model makes it possible to conduct predictive calculations of the energy spectrum of implanted platinum ions on the basis of experimental data on the main physical characteristics of the pulsed laser plasma and technical parameters of the high-voltage system. The study of ion-implanted layers in the n-6H-SiC crystals have revealed features of structural and phase variations in the surface layers of the crystal at various doses of “hot” (600°C) ion implantation. On the basis of an analysis of experimental data, it is suggested that there are different solid-state reactions of platinum with silicon carbide in relation to the dose of implantation; these reactions cause a loss or acquisition of catalytic properties of nanosystems in the formation of platinum silicides or metal-like clusters, respectively. Optimization of the dose of ion implantation of platinum makes it possible to fabricate an on-chip n-6H-SiC structure, which varies the electrical parameters in a hydrogen-containing environment at elevated temperatures.