Very high temperature annealing effect on amorphous carbon films grown on refractory oxide substrates by pulsed laser deposition

We have carried out very high temperature heat treatment at 1400–2700°C of about 10nm-thick amorphous carbon thin films deposited on refractory substrates MgO, Al2O3, and yttria-stabilized zirconia (YSZ) using pulsed laser deposition techniques. After the annealing, a few nanometer scale sp2 crystallization of the films and a large corrugation with a height of more than 1μm were observed by Raman spectroscopy analysis and optical/atomic force microscopes, respectively. The corrugation is probably caused by the formation of gases at the film/substrate interface during the heat treatment.