Nitrogen-Doped ZnO Film Fabricated Via Rapid Low-Temperature Atomic Layer Deposition for High-Performance ZnON Transistors

Abstract

High-performance nitrogen-doped ZnO (ZnON)-based thin-film transistors (TFTs) were fabricated by atomic layer deposition (ALD) with a rapid purging time of only 5 s at a temperature as low as 150 °C. It is the first time to report ALD ZnON TFT using NH3 as N source. It is found that ZnON TFT with a N: Zn atomic ratio of 1:19 (ZnON 1:19) exhibited excellent properties, such as lower subthreshold swing of 0.47 V/decade and smaller $\Delta {V}_{\textsf {th}}$ of 0.71 V under the temperature stress from 25 to 105 °C. The ${I}_{ \mathrm{\scriptscriptstyle ON}}$ and ${I}_{ \mathrm{\scriptscriptstyle OFF}} $ decreased as N-doping concentration increased, and ZnON 1:19 TFT presented a high ${I}_{ \mathrm{\scriptscriptstyle ON}}/{I}_{ \mathrm{\scriptscriptstyle OFF}}$ ratio of 1.75 $\times \,\,10^{\textsf {7}}$ . The density of state was calculated by temperature stress. Combining with the X-ray photoelectron spectroscopy analysis, we built a model to explain the reaction mechanism that the moderate amount of N doping could significantly suppress the creation of oxygen defects.