High temperature dielectric properties of SiO2 films deposited by TEOS PECVD

The electrical characteristics of SiO2 film deposited by TEOS-PECVD for primary passivation of power components in silicon carbide are studied. Although this type of films are widely used, their properties when the temperature reaches 250 °C or more are little known. Such high temperatures are required for the new high temperature operating SiC devices. The study shows that a heat treatment of this type of deposited SiO2 improves its electrical performance. The dielectric strength of the films, annealed at 400 °C for one hour in nitrogen atmosphere, is measured in a wide range of temperature up to 300 °C. The results indicate that this type of material is an excellent candidate for the primary passivation of high-temperature operating power device. In fact, a dielectric strength of 6 MV/cm at 300 °C is a very high value in comparison with other insulating materials used in power components.