Non-ideal effects improvement of SF6 plasma treated hafnium oxide film based on electrolyte–insulator–semiconductor structure for pH-sensor application

A novel HfO2 thin film with SF6 plasma treatment as ion selective membrane on electrolyte–insulator–semiconductor structure for pH-sensor was proposed. The sensing characteristics on hydrogen ion detection and the non-ideal effects including drift effect, hysteresis phenomenon, and responses on interference ions were all presented in this article. The results show that the slight increase of pH-sensitivity is achieved and the non-ideal effects are improved after SF6 plasma treatment. It is finally concluded that the HfO2 thin film with SF6 plasma treatment as ion selective membrane is suitable for pH detection and the optimum condition is 5 min for SF6 plasma treatment.