The Effect of Thermal Annealing on the Properties of IGZO TFT Prepared by Atmospheric Pressure Plasma Jet

We fabricated bottom gate TFTs with IGZO channel layer deposited by atmospheric pressure plasma jet (APPJ). The effect of thermal annealing on the properties of IGZO TFTs was studied. After post annealing, the IGZO thin films showed a smooth and dense structure. The transistors annealed at 300oC showed clear switching behavior with a negative threshold voltage of -0.571 V and a mobility of 2.6 cm2/V-s. After 500oC post annealing, IGZO thin film showed an amorphous-like phase and the average transmittance is more than 80% in the visible range. Good electrical characteristics were achieved, including a threshold voltage of 6.74V, a subthreshold swing of 1.54 V/dec, a mobility of 10.31 cm2/V-s and a large Ion/Ioff ratio of 3.28x108.