Drift and Hysteresis Effects Improved by RTA Treatment on Hafnium Oxide in pH-Sensitive Applications

Rapid thermal annealing (RTA) treatment in ambient is applied to optimize the drift and hysteresis effects of -based sensing membrane. The drift coefficient of the thick -electrolyte-insulator-semiconductor (EIS) structure was . After being treated with RTA at , the drift coefficient and hysteresis width of the thick layer was reduced to and , respectively. For the -EIS structure treated with RTA at , the drift coefficient was increased to because of the crystallization of the layer and was improved by annealing due to the densification of the layer. Therefore, the drift coefficient of the -EIS structure was reduced to by RTA treatment at . With excellent pH sensitivity and stability, an layer with proper RTA processing can be used as pH sensing material in ion-sensitive field-effect transistor-type sensors. Moreover, to easily control capacitance–voltage measurements and automatically calculate parameters such as pH sensitivity, drift coefficient, and hysteresis width of an -EIS structure, a program based on LabVIEW was developed.