Effect of oxygen-modification on the switching of ZnO TFT

In this work, two methods for incorporating oxygen atoms to improve the quality of zinc oxide thin films are proposed. The first method involves modifying the film using oxygen plasma. The plasma bias enables the mild implantation of oxygen atoms into the film. However, O₂ plasma can increase oxygen vacancy defects due to ion bombardment of the zinc oxide film and may also damage the gate insulator–channel interface of the thin-film transistor. The second method introduces oxygen gas in-line to actively participate in the zinc oxide formation process. This in situ doping approach effectively suppresses the formation of oxygen vacancies and controls the carrier concentration, leading to a positive shift in the threshold voltage and improved quality of the gate insulator–channel interface. As a result, the switching behavior of the thin-film transistor is optimized.