Low Power Thin Film Transistor

The carbon doped silicon oxide (SiOC) as a gate insulator was prepared on p-type Si substrate with the oxygen gas flow rates of 16-24 sccm by a RF magnetron sputter. The bonding structure of SiOC changed from the crystal to amorphous structure with increasing the oxygen gas flow rates because the potential barrier increased with increment of oxygen contents. The aluminum doped zinc oxide (AZO) channel thin film transistor (TFT) was achieved on SiOC as a gate insulator by a RF magnetron sputtering system, and the transfer curve of AZO transistor was directly influenced by the characteristic of SiOC. AZO transistor on an amorphous SiOC with high Schottky barrier was observed the ambipolar behavior. The matched interfaces between amorphous SiOC and AZO channel improved to increase the mobility of TFTs depending on the high Schottky barrier and the low drain voltage. AZO TFT prepared on the crystal structure SiOC with Ohmic contact as a positive resistance showed the unipolar transfer characteristics. The TFT with ambipolar transfer characteristics due to the high Schottky barrier as a negative resistance operated at low current about similar to 10(-7) A, and it could be prospected as low power device.