Preparation of superior IGZO ceramics by two-step sintering for application in IGZO thin film fabrication

Abstract

The preparation method of advanced ceramics that serve as target materials, has been the key challenge to produce high quality thin film transistors (TFTs) with the desired properties. In this study, a novel two-step sintering (TSS) process was successfully applied to fabricate indium gallium zinc oxide (IGZO) ceramics. The sintering behaviour of the IGZO compacts was investigated in detail and it was established that the first step optimum temperature should be in the range of 1400–1500 ℃, while for the second step should be 1350℃ with a dwell time of 12 h. Using this method, the relative density, average grain size and resistivity of the IGZO ceramics could reach 99.5%, 4–5 μm and 2.31 mΩ⋅cm, respectively. The corresponding IGZO thin films produced from the ceramic through sputter deposition had an average transmittance of over 88% and a low resistivity of 3.56 mΩ⋅cm. These excellent properties suggest that TSS has considerable potential as a viable approach for the preparation of ceramic target materials, which find application in the fabrication of TFTs.