In this letter, we report trilayer ZnO thin-film transistors (TFTs) with in situ Al2O3 passivation fabricated using plasma-enhanced atomic layer deposition. The bottom-gate, top-contact TFTs use an Al 2O3ZnO-Al2O3 trilayer deposited in one deposition run at 200 °C that provides protection for the active layer back surface with no extra passivation step. Compared with Al2O 3 passivated, nontrilayer ZnO TFTs, these trilayer devices have similar field effect mobility, but more positive turn-on voltage and improved bias stability. Seven-stage trilayer ZnO TFT ring oscillators operated at 3.5 MHz at a supply voltage of 17 V, corresponding to a propagation delay of 27~ns\stage.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering