High-Performance Sputter-Prepared Metal-Oxide Thin-Film Transistors Based on Solution-Processed Targets

Metal-oxide (MO) thin-film transistors (TFTs) can be made using low-cost solution-processing methods, which however, generally show compromised TFT performances partially arising from the low film density. To address this challenge, here we proposed a method that employed solution-processed MO film as a target to prepare sputtered MO TFTs. For purposes of illustration, Pr doped indium gallium oxide (InGaPrO) was chosen as the main MO semiconductor material to be studied. The sputter-prepared In 0.619 Ga 0.336 Pr 0.045 O x TFTs based on solution-processed film targets exhibited a saturation mobility (μ sat ) of 10.37 ± 0.41 cm 2 /Vs, a turn-on voltage ( V on ) of -1.42 ± 0.37 V, an I on / I off ratio of >1 × 10 8 , and negligible hysteresis, while the conventional solution-processed counterparts displayed an inferior μ sat of 1.59 ± 0.11 cm 2 /Vs. Negative bias illumination stress stability tests revealed that sputter- and solution-processed InGaPrO TFTs had negative V on shifts of 5.4 and 1.2 V, respectively, which is mainly related to the change in film density. The proposed method was further extended to fabricate low-temperature, high-performance InO x and In 0.95 Pr 0.05 O x TFTs with μ sat of 24.33 ± 0.42 cm 2 /Vs and 21.82 ± 0.81 cm 2 /Vs, revealing the potential of using solution-processed film targets for fabricating a wide range of sputtered MO TFTs.