With the development of flat panel display technology, higher performance requirements are put forward for thin film transistors used in drive circuits, and it is urgent to develop oxide thin film transistors with higher mobility and lower thermal budget. In this work, bandgap-tunable InSnZnO (ITZO) thin films are deposited using plasma-enhanced (PE) atomic layer deposition (ALD) at 180 °C. Then all-oxides ITZO thin-film transistors with different In:Sn:Zn component proportion channels and ITO source/drain electrodes are fabricated at a low thermal budget of 200 °C. By optimizing the indium content, the proposed ITZO transistor exhibits a high field effect mobility of 28.69 cm²/Vs, a high On/Off current ratio of 10⁸, and a quite small subthreshold swing (SS) of 71 mV/dec. The small SS could be attributed to the in-situ interfaces engineering for the channel layer and the gate dielectric layer, there is no without air-breaking during the depositions of two films layers in the same chamber. Finally, the negative/positive-bias temperature stress results indicate that the all-oxides ITZO TFT based on In:Sn:Zn (1:1:1) film has good stability. These results illustrate that the PEALD-derived all-oxides ITZO TFT is a promising candidate for the next generation flat panel display technology applications.