Improving the Performance of the ToGoFET Probe: Advances in Design, Fabrication, and Signal Processing

Area of Science:

• Electrical Engineering
• Materials Science
• Nanotechnology

Background:

• Capacitive measurements are crucial for various sensing applications.
• Existing tip-on-gate field-effect-transistor (ToGoFET) probes have limitations in sensitivity and reliability.
• Improvements in probe design and fabrication are needed to enhance performance.

Purpose of the Study:

• To report recent improvements in the tip-on-gate field-effect-transistor (ToGoFET) probe for capacitive measurements.
• To detail modifications in probe structure, fabrication, and signal processing.
• To demonstrate enhanced imaging performance and sensitivity.

Main Methods:

• Redesigned the inbuilt metal-oxide-semiconductor field-effect-transistor (MOSFET) for reliable operation.
• Modified the standard complementary metal-oxide-semiconductor (CMOS) fabrication process, including trench formation and channel definition.
• Optimized demodulation of amplitude-modulated drain current to improve the signal-to-noise ratio.

Main Results:

• The redesigned MOSFET exhibited improved I-V characteristics, reflecting design and fabrication modifications.
• Enhanced signal-to-noise ratio was achieved through optimized demodulation techniques.
• The improved ToGoFET probe demonstrated a 20-fold enhancement in the minimum measurable value.
• Successful imaging of a buried electrode confirmed improved performance.

Conclusions:

• The reported modifications significantly enhance the performance of ToGoFET probes for capacitive measurements.
• The redesigned MOSFET and optimized fabrication process contribute to improved reliability and sensitivity.
• The enhanced ToGoFET probe offers a 20-fold improvement in minimum measurable value, enabling more sensitive detection.