Thin film transistor and method for making the same

A method for making thin film transistor, the method comprising:

• providing a substrate;
• depositing a gate on the substrate;
• forming a first sub-dielectric layer on the gate by magnetron sputtering, wherein the first sub-dielectric layer is a first oxide dielectric layer and in direct contact with the gate;
• forming a second sub-dielectric layer on the first sub-dielectric layer, wherein the second sub-dielectric layer is an aluminum oxide layer (AlO3), a silicon dioxide layer (SiO2), a hafnium oxide (HfO2) layer, or a silicon nitride (Si3N4 layer) and grown by atomic layer deposition, electron beam evaporation, thermal oxidation, or plasma-enhanced chemical vapor deposition;
• applying a semiconductor layer on the second sub-dielectric layer, where the semiconductor layer comprises a plurality of nano-scaled semiconductor materials;
• and forming a source and a drain on the second sub-dielectric layer, wherein the source and the drain are spaced apart from each other and are electrically connected to the semiconductor layer, wherein the first sub-dielectric layer causes an inverse current hysteresis in the thin film transistor as compared with the second sub-dielectric layer so that the thin film transistor has a reduced current hysteresis.