Transparent ZnO-TFT Arrays fabricated by atomic layer deposition

Abstract

Transparent ZnO thin film transistor (TFT) array of 176 x 144 (106 dpi) was fabricated on glass substrate. The V-th of the TFT with inverted coplanar structure is about 0.8 V and the mobility is 1.13 cm(2)/V s. The active layer (ZnO), gate insulator (Al2O3), and source-drain electrode (ZnO:Al) were deposited by atomic layer deposition. We also compared the performance of TFTs fabricated by lift-off and wet-etching process as the patterning processes of ZnO layer. The carrier density of the ZnO layer was carefully adjusted to reduce off-current of TFT. Good contact with small contact resistance was formed between the active layer and the source-drain electrode.