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 In0.619Ga0.336Pr0.045Ox TFTs based on solution-processed film targets exhibited a saturation mobility (
$\mu _{\text {sat}}{)}$
of 10.37 ± 0.41 cm2/Vs, a turn-on voltage (
${V}_{\text {on}}{)}$
of −1.42 ± 0.37 V, an
${I}_{\text {on}}/{I}_{\text {off}}$
ratio of >
$1\times 10^{{8}}$
, and negligible hysteresis, while the conventional solution-processed counterparts displayed an inferior
$\mu _{\text {sat}}$
of 1.59 ± 0.11 cm2/Vs. Negative bias illumination stress stability tests revealed that sputter- and solution-processed InGaPrO TFTs had negative
$V_{\text {on}}$
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 InOx and In0.95Pr0.05Ox TFTs with
$\mu _{\text {sat}}$
of 24.33 ± 0.42 cm2/Vs and 21.82 ± 0.81 cm2/Vs, revealing the potential of using solution-processed film targets for fabricating a wide range of sputtered MO TFTs.