Effect of mid-annealing process on the device characteristics of the TFT using Al-doped ZnO active channels prepared by atomic layer deposition

A mid-annealing process was proposed to control both parameters of the carrier concentration and crystal orientations for the atomic-layer deposited Al-doped ZnO (AZO) thin films. It was defined as an additional thermal treatment in oxygen ambient for the prepared AZO films right after the channel area patterning process during the TFT fabrication procedures. It was confirmed that the electrical conductivity showed drastic changes in the AZO films prepared at 150 and 200 ^oC without any marked variations in their crystallographic nature. Sound transfer characteristics were also obtained via mid-annealing process for the fabricated AZO TFTs, which had shown totally conductive natures in absence of the proposed process. Further optimization should be investigated for obtaining higher device performances.