Dose dependence of the enhancement of thermal oxidation for 6H-SiC by 30 keV O-18(+) and Ne-20(+) irradiation

The oxidation rate of the Si-face of 6H-SiC was significantly enhanced by 3 0 keV O-18(+) and Ne-20(+) irradiation at high doses followed by thermal an nealing at 1100 degrees C in a wet oxygen atmosphere. This oxidation rate s trongly depends on the ion dose. We found three regions of oxidation rate d ependence on the ion dose. The three regions show the same low oxidation ra te as that of the standard SiC, an oxidation rate with increased values and an oxidation rate with the fastest and saturated value. The dose dependenc es of the total damage obtained from Ruterford backscattering spectroscopy (RBS) measurements and of the oxide thickness are different. However, the d ose dependence of the spin density determined from electron spill resonance (ESR) measurements corresponded to. The high density of dangling bonds in SiC induced by ion irradiation is considered to result in the increase of t he diffusion coefficients for oxygen in SiC. Therefore, the oxidation rate of SIC is significantly enhanced. The enhanced oxidation was found to be re lated to the quality of the damaged layer and required higher dose than the dose necessary for amorphization, which was determined from RES and ESR me asurements.