REVERSIBLE HYDROGEN ANNEALING OF METAL-OXIDE-SILICON CARBIDE DEVICES AT HIGH-TEMPERATURES

We report on a reversible hydrogen annealing effect observed in platin um-silicon dioxide-silicon carbide structures at temperatures above ab out 650 degrees C. It appears as a decrease of the inversion capacitan ce in the presence of hydrogen. This phenomenon is shown to depend on hydrogen atoms, created on the catalytic metal, that pass through the oxide and interact with charge generation sites at the oxide-silicon c arbide interface. The consequence of the observation for chemical sens ors based on silicon carbide is discussed. The results are phenomenolo gical, since no details of the annealing chemistry could be developed from the present experiments. We find, however, that the annealing pro cess and its reversal have activation energies of about 0.9 eV and 2.9 eV/site,respectively. (C) 1995 American Institute of Physics.