The Ion Sensitivity of Boron Implanted Silicon Nitride Chemical Sensors

Silicon nitride has been widely used as a pH sensing insulator on the gate of the ion sensitive field effect transistor (ISFET) employed in CMOS integrated chemical sensors. In this paper, we report experimental results on the H+sensitivity of heavily boron-implanted silicon nitride (Si3N4). Ion implantation provides a microelectronics technology compatible approach to modify the surface of insulators and tailor the ion sensitivity of ISFETs. This work has suggested new possibilities to study the multiple-site site-binding model for blocking insulators. The composition of the surface sites (nature and number of sites), can be conveniently controlled by implant ion species and dose. © 1989, The Electrochemical Society, Inc. All rights reserved.