Correlation Between Currents, X-ray Diffraction Patterns and Transfer Characteristics of SnO₂ Thin Film Transistor.

SnO₂ thin film transistor (TFT) was prepared with SiOC as a gate insulator on n-type Si and the correlation between bonding structures, the contact properties of SnO₂ thin films and the transfer characteristics of TFTs was researched. The current of SnO₂ thin films increased with increasing the crystallinity and the crystallinity of SnO₂ was increased by annealing. The SnO₂ deposited with much oxygen gas flows became an amorphous structure after annealing due to lowered crystallinity. On the other hand, the current decreased in the amorphous structure SnO₂ with high oxygen vacancies. However, the ambipolar transfer characteristics of SnO₂/SiOC TFT with an amorphous structure had higher stability-mobility than that of TFT with the crystallinity, because of the increment effect of the diffusion current at the depletion layer as the amorphous structure with high Schottky barrier (SB).