Preparation and characterization of SiO2/6H–SiC metal–insulator–semiconductor structure using TEOS as source material

Insulating SiO2 layer was deposited on 6H–SiC by chemical vapor deposition (CVD) method using tetraethyl orthosilicate (TEOS; Si(OC2H5)4) as a source material. The substrate was research grade n-type 6H–SiC. The SiO2 film was deposited at 750 °C. Metal–insulator–semiconductor (MIS) capacitor was prepared to evaluate the interface properties between SiC and SiO2. The sample showed capacitance–voltage curves with hysteresis loops and deep depletion characteristics. Interface-state density near mid-gap was 5×1011 cm−2 eV−1, and was lower than that for the sample prepared on same substrate using thermally grown oxide as an insulating layer. Post-deposition annealing at 1000 °C in wet O2 atmosphere resulted in increase in interface-state density.