No abstract

Low voltage oxide thin-film transistors (TFTs) operating below 1.0 V were developed using a high dielectric constant tantalum oxide produced by thermal oxidation. Thermal oxidation was carried out at 400, 500, and 600 °C under an oxygen atmosphere. The tantalum oxide was evaluated by X-ray photoelectron spectroscopy (XPS). XPS confirmed the binding energy of Ta4f, indicating the binding state of tantalum oxide. The bottom gate oxide TFT with the gate insulator of tantalum oxide grown at 500 °C exhibited mobility of 12.61 cm2/V and a threshold voltage of 0.46 V. The transfer characteristics at the drain voltages below 1.0 V show its applicability to low voltage operation below 1 V. The bootstrapped inverter with developed oxide TFTs operated well at the operation voltages of both the 1.0 and 2.0 V.

AMOLED pixel circuit was proposed to compensate for reduced luminance by both the stretching and IR drop on power line. In addition, the proposed circuit keeps compensation function for both the positive and negative shift. The proposed circuit was verified by the simulation for the negative shift of threshold voltages, IR drop at power bus line and the stretching induced luminance change.

Low voltage oxide thin film transistor (TFT) was developed using high dielectric gate insulator by thermal oxidation of tantalum metal. Thermal oxidation was carried out after deposition of tantalum layer by sputtering. Thermal grown tantalum oxide was analyzed by HR‐TEM and XPS. Through XPS analysis, it was confirmed that the binding energy of Ta4f indicates the formation of tantalum oxide. And the clear O1s peak has good Ta‐O bond. The transfer characteristic of the developed oxide transistor showed mobilities over 10 cm2/V·s and the inverter circuit operating below 1 V was achieved.