A New “Ammonia Bath” Method for Realizing Nitrogen Doping in ZnSnO Transistors

This work develops a novel “ammonia bath” method of realizing nitrogen anion rapid doping in ZnSnO (ZTO:N) thin film transistors (TFTs). The preparation, electrical properties and stability of ZTO:N TFTs are investigated. Based on X-ray photoelectron spectroscopy analysis, the oxygen vacancies of ZTO thin films decrease significantly from 25.4 % to 15.6 % with N doping. The results also demonstrate that positive bias stability is enhanced dramatically. The ZTO:N TFT with “ammonia bath” of 4 min shows a low threshold voltage shift of 0.18 V compared with 2.13 V of ZTO TFT. The improved stability and electrical properties of TFTs are attributed to suppression of oxygen-related defects caused by N.