Study on ZnO micron channel length thin film transistors using different metal electrodes

Scaling behaviors of ZnO thin film transistors (TFTs) with channel lengths down to 2 mu m have been systematically studied by using different electrode materials (Ti, Mo, Sn and Ag), in order to be able to drive micro light emitting diodes (micro-LEDs) whose ideal sizes are expected to be around 5 mu m. The apparent threshold voltage roll-off is observed for ZnO TFTs with Ti and Mo as electrodes, while it can be ignored when Sn and Ag are used as electrodes. Even if the channel length is as short as 2 mu m, the ZnO TFTs demonstrate a mobility of 24 cm2V-1s-1, ION/IOFF ratio of 107 and width normalized contact resistance (W.RSD) of 1.5 Omega cm (VGS = 15 V) if Ag is used as electrodes, rendering enough current to drive micro LEDs. (c) 2021 Elsevier B.V. All rights reserved.