Evaluation of SiO2 films for the application to a flexible substrate

SiO₂ films deposited by RF sputtering at room temperature have been investigated for the gate insulator of TFTs. As a result of mixing oxygen into argon gas during deposition, leakage current of the film decreased, and the breakdown voltage increased over 8 MV/cm. From high-frequency C-V characteristics, hysteresis was reduced from 2.5 to 0.04 V by performing 4% H₂ annealing after the deposition. These results suggest that RF sputter-deposited SiO₂ film is promising for a gate insulator in TFTs of low heat-resistant substrate.