Quality and reliability of wet and dry oxides on n-type 4H-SiC

The thermal oxide on silicon carbide (SiC) is found to be subtly different from that grown on silicon and many basic oxide characterisation experiments still remain to be carried out. Here a comparison is made between the breakdown properties and wet and dry thermally grown oxides on n-type 4H-SiC over the temperature range 25–300°C. The interface characteristics are also compared for the two oxides. It was found that for temperatures up to 200°C the dry oxide could have more than an order of magnitude larger charge to breakdown than that found for the wet oxide, whilst having no significant difference in interface state density or fixed oxide charge. At 300° the breakdown mechanism changed and became process independent.