Low Leakage Current Vertical Thin-Film Transistors With InSnO-Stabilized ZnO Channel

Vertical channel InSnO (ITO)-stabilized ZnO thin-film transistors (TFTs) with a channel length of 300 nm were developed and fabricated. These TFT devices exhibited low off-state leakage current and gate leakage current coming into the scale of 10
^-14
A. In addition, a high on/off current ratio was achieved, up to 10
⁷
, with a drain voltage of 0.01 V. The effects of the overlap area between the source and drain region on the electrical performance of the proposed vertical TFTs were investigated. The results showed that the vertical channel ITO-stabilized ZnO TFTs with a smaller overlap exhibited a better switching speed, whether in DC or AC mode. The proposed vertical channel ITO-stabilized ZnO TFTs may be promising for application in flexible and high-density electronics.