Ion-sensing devices with silicon nitride and borosilicate glass insulators

• Published in: IEEE transactions on electron devices Vol. 34; no. 8; pp. 1700 - 1707
• Main Authors: Harame, D.L., Bousse, L.J., Shott, J.D., Meindl, J.D.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.1987; Institute of Electrical and Electronics Engineers
• Subjects: Exact sciences and technology; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Other topics in instruments, apparatus, components and techniques common to several branches of physics and astronomy; Physics; Measurement; Field effect transistor; Electrolyte; Ionization
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/T-ED.1987.23140

Ion-sensitive field-effect transistors (ISFET's) with silicon dioxide, silicon nitride, and borosilicate glass as the active gate material were fabricated and tested for pH-sensing applications. The borosilicate glass and silicon nitride devices were found to have a linear potential/pH response and previous theories of ISFET function were inadequate to explain this. A two-site theory is presented that can explain the features of the potential/pH response of both silicon nitride and borosilicate glass ISFETs. The model is easily extended to any two-site system.