A highly pH-sensitive nanowire field-effect transistor based on silicon on insulator

Area of Science:

• Nanotechnology
• Semiconductor Devices
• Chemical Sensing

Background:

• Investigates silicon-on-insulator (SOI) based silicon nanowire field-effect transistors (FETs).
• Utilizes CMOS-compatible fabrication methods for device realization.

Purpose of the Study:

• To experimentally and theoretically analyze the performance of CMOS-compatible silicon nanowire FETs.
• To evaluate the pH sensitivity and charge sensitivity of the developed sensor.

Main Methods:

• Fabrication of silicon nanowire FETs using CMOS-compatible top-down approaches.
• Experimental measurement of Nernstian sensitivity to pH changes.
• Theoretical estimation of charge sensitivity in subthreshold mode.

Main Results:

• Achieved a maximum Nernstian sensitivity of 59 mV/pH.
• Estimated maximum charge sensitivity on the order of 10^-3 electron charge in subthreshold operation.

Conclusions:

• The CMOS-compatible top-down fabrication approach yields sensor sensitivity comparable to bottom-up methods.
• The developed sensor provides a foundation for creating integrated CMOS-compatible probes with on-chip signal processing capabilities.