Influence of deposition condition on electrical properties of a-IGZO films deposited by plasma-enhanced reactive sputtering

The effects of sputtered atom flux on the electrical properties of a-IGZO films before and after thermal annealing were examined by varying the fluxes of sputtered atoms at the substrate holder. The electrical proprieties of IGZO TFTs fabricated from a-IGZO films were found to vary widely depending on the sputtered atom flux. Specifically, the electrical properties of a-IGZO films after thermal annealing improved considerably with increasing sputtered atom flux, such that a field effect mobility as high as 23.6 cm2V−1s−1 was achieved following annealing. These results suggest that the electrical characteristics of IGZO TFTs after annealing are affected by the film structure, including the density and quality of the as-deposited a-IGZO films.