Electrochemical Characterization of Ion-Sensitive Capacitors with ALD Al2O3 as the Sensitive Dielectric

The physical, chemical and electrochemical characterization of sensitive materials used for ion-sensitive capacitive sensors (ISCAPs) has been performed. These sensors were designed with a single-metal level fabrication process (first metal level of an integrated circuit), and include special capacitive features which could help to increase the sensitivity of the devices (through modulation of their flat-band voltage). Additionally, an integrated quasi-reference electrode has been included in the design, thus enabling measurements without using any conventional external electrode. Based on previous results of the chemical and morphological characterization of materials after immersion in buffer solutions, it is expected that these sensors will provide high sensitivity and a stable response for pH measurements in the short-term.