A low-leakage-current CdSe thin film transistor

Abstract

This paper reports the design, fabrication, and performance of a very low-leakage-current thin film transistor (TFT). The TFT had a double-gate structure and used a 80–100 Å thick CdSe thin film as the semiconductor. The free charge carrier concentration in the semiconductor film was calculated to be 5×10 14/cm 3. These factors contributed to achieving a zero-gate-bias current less than 10 −10 A in the TFT. The ON/OFF current ratio of the TFT was measured to be greater than 10 6. The TFT had acceptable stability in the ON condition and excellent stability in the OFF condition. A life test was performed on a TFT under a zero-gate-bias condition. After 1100 hr of testing, the zero-gate-bias current of the TFT increased from 5.8×10 −10 A to 9×10 −10 A. With extrapolation, the TFT had more than 10,000 hr lifetime.