Transparent ZnO-TFT Arrays Fabricated by Atomic Layer Deposition

Transparent ZnO thin film transistor ͑TFT͒ array of 176 ϫ 144 ͑106 dpi͒ 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 ͑ZnO͒, gate insulator ͑Al 2 O 3 ͒, and source-drain electrode ͑ZnO:Al͒ 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.