High sensing performance of fluorinated HfO2 membrane by low damage CF4 plasma treatment for K+ detections

A low damage CF
4
plasma with a filter in a PECVD system was proposed to incorporate fluorine atoms into an HfO
2
sensing membrane in an EIS structure for K
⁺
ion sensor application. The highest sensitivities of 82mV/pK was obtained when the low damage plasma treatment with RF power of 100W was used for 30min. Compared with the conventional CF
4
plasma, the sensitivity significantly improved. The reasons were the high polarization induced by fluorine atoms and elimination of plasma damage.