Low-temperature thermal oxidation of ion-amorphized 6H-SiC

Abstract: The aim of this work is the determination of the wet oxidation growth rate on different SiC phases. Thermal oxidations were performed in the temperature range 750 - 1100 degreesC on Ar+ ion-amorphised 6H-SiC, polycrystalline and unimplanted 6H-SiC samples. RBS and TEM were used to analyse the oxidised samples. The results obtained in this work show that the oxidation rate on different SiC phases is determined by the amount of disorder present at the sample surface. The highest oxidation rates are found on as-implanted samples at oxidation temperatures below 900 degreesC where an amorphous SiC layer is still present at the sample surface. The re-crystallisation of the ion-amorphised surface layer takes place already at temperature as low as 885 degreesC. Above this temperature, oxidation and re-crystallisation are competitive phenomena, a slow down of the oxidation rate being observed when the re-crystallisation of the amorphous SiC layer is completed. In an intermediate temperature range, centred around 910 degreesC, an enhanced oxidation phenomenon related to an uncompleted re-crystallisation is observed for the first time.