Overcoming the quantification barrier in reverse tip sample scanning spreading resistance microscopy for efficient...

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Reverse tip sample (RTS) scanning probe microscopy (SPM) offers efficiency gains, particularly in high-force modes like scanning spreading resistance microscopy (SSRM).
• Previous RTS SSRM advancements focused on probe fabrication and qualitative measurements, but quantitative carrier profiling remained elusive due to focused ion beam (FIB) induced sample damage.
• Accurate carrier profiling is crucial for semiconductor device analysis and material science.

Purpose of the Study:

• To develop and validate focused ion beam (FIB)-based sample preparation protocols for quantitative carrier profiling using reverse tip sample (RTS) scanning spreading resistance microscopy (SSRM).
• To overcome the challenge of FIB damage in RTS sample preparation for reliable electrical measurements.
• To enable accurate and efficient carrier concentration analysis in semiconductor materials.

Main Methods:

• Two distinct FIB-based RTS sample preparation protocols were developed: sequential sample mounting and unified assembly bonding.
• Co-mounting target and calibration samples on a single tipless cantilever to ensure identical ion beam exposure.
• Quantitative validation using staircase calibration samples with known carrier concentrations and comparison with conventional SSRM.

Main Results:

• The developed protocols successfully enabled quantitative carrier profiling using RTS SSRM, overcoming previous limitations caused by FIB damage.
• Both sequential and unified assembly preparation methods yielded accurate SSRM quantification when validated with calibration samples.
• Results from RTS SSRM were found to be equivalent to conventional SSRM, demonstrating its quantification reliability.

Conclusions:

• This work establishes quantitative carrier profiling capabilities for RTS SSRM, addressing a critical gap in electrical SPM characterization.
• The presented FIB preparation protocols offer a reliable method for accurate carrier concentration measurements in semiconductor research and development.
• RTS SPM, particularly in its quantitative SSRM configuration, is positioned as a valuable tool for advanced electrical characterization of materials and devices.