Enhancement of Ion-Sensitive Field-Effect Transistors through Sol-Gel Processed Lead Zirconate Titanate Ferroelectric Film Integration and Coplanar Gate Sensing Paradigm

• Published in: Chemosensors 2024-07, Vol.12 (7), p.134
• Main Authors: Mah, Dong-Gyun, Oh, Seong-Moo, Jung, Jongwan, Cho, Won-Ju
• Format: Article
• Language: English
• Subjects: Annealing; Business metrics; Design and construction; Electric properties; Electrical properties; extended fate ion-sensitive field-effect transistors (EG-ISFETs); ferroelectric field-effect transistors (FeFETs); Ferroelectric materials; Ferroelectricity; Field effect transistors; Glass substrates; Indium; ion-sensitive field-effect transistors (ISFETs); lead zirconate titanate (PZT) ferroelectric films; Lead zirconate titanates; Metallic films; methodologies for pH sensing; Performance measurement; Semiconductor devices; Sensitivity enhancement; Sensors; Sol-gel processes; Thin films; Transistors; Tungsten; Tungsten oxide
• ISSN: 2227-9040; 2227-9040
• DOI: 10.3390/chemosensors12070134

To facilitate the utility of field effect transistor (FET)-type sensors, achieving sensitivity enhancement beyond the Nernst limit is crucial. Thus, this study proposed a novel approach for the development of ferroelectric FETs (FeFETs) using lead zirconate titanate (PZT) ferroelectric films integrated with indium–tungsten oxide (IWO) channels synthesized via a cost-effective sol-gel process. The electrical properties of PZT-IWO FeFET devices were significantly enhanced through the strategic implementation of PZT film treatment by employing intentional annealing procedures. Consequently, key performance metrics, including the transfer curve on/off ratio and subthreshold swings, were improved. Moreover, unprecedented electrical stability was realized by eliminating the hysteresis effect during double sweeps. By leveraging a single-gate configuration as an FeFET transformation element, extended-gate (EG) detection methodologies for pH sensing were explored, thereby introducing a pioneering dimension to sensor architecture. A measurement paradigm inspired by plane gate work was adopted, and the proposed device exhibited significant resistive coupling, consequently surpassing the sensitivity thresholds of conventional ion-sensitive field-effect transistors. This achievement represents a substantial paradigm shift in the landscape of ion-sensing methodologies, surpassing the established Nernst limit (59.14 mV/pH). Furthermore, this study advances FeFET technology and paves the way for the realization of highly sensitive and reliable ion sensing modalities.