Characterization of Aluminum Silicate (AlSiO) Insulator Films

Abstract

An attractive gate insulator film with a wide bandgap and a high dielectric constant is required to achieve high performance power field-effect transistor (FET) using wide bandgap semiconductors such as SiC and diamond. An Al₂O₃ film is one of the candidates for this purpose. The AlO film was produced by means of RF sputtering on Si and SiC substrates, and I-V and C-V characteristics of the AlO film were measured. However, the AlO film was not stoichiometric and it has large gate leakage current and large charge shifts. So we added Si in AlO (AlSiO).
We have succeeded in suppressing the gate leakage current and the charge shifts by using the AlSiO film. The optimized AlSiO film was applied to SiC-MIS structure. It was also observed that the leakage current level was suppressed.