Preventing probe induced topography correlated artifacts in Kelvin Probe Force Microscopy

Area of Science:

• Surface science
• Scanning probe microscopy
• Nanotechnology

Background:

• Kelvin Probe Force Microscopy (KPFM) is a powerful technique for measuring surface potential.
• Rough sample topography can introduce artifacts in KPFM measurements, complicating data interpretation.
• Homogeneous probe coatings are crucial for reliable KPFM on non-flat surfaces.

Purpose of the Study:

• To investigate and mitigate topography-correlated artifacts in KPFM.
• To evaluate the impact of probe inhomogeneity on KPFM measurements.
• To identify optimal probe materials and experimental conditions for artifact-free KPFM.

Main Methods:

• Amplitude Modulation (AM) KPFM and Frequency Modulation (FM) KPFM were employed.
• Experiments were conducted on gold-coated samples with rough topography.
• Homogeneously and inhomogeneously coated probes (PtIr, Au, TiN) were utilized.

Main Results:

• Homogeneously coated probes and proper experimental setup eliminated topography-correlated artifacts in AM-KPFM.
• Probe inhomogeneity, induced by sample contact, caused artifacts in both AM- and FM-KPFM.
• Lift height dependence of KPFM measurements indicated probe-induced artifacts.

Conclusions:

• Maintaining probe homogeneity and preventing tip alteration is essential for accurate KPFM on rough surfaces.
• TiN-coated probes demonstrated superior resistance to coating damage, making them suitable for KPFM.
• The study provides a model for understanding and preventing KPFM artifacts related to probe inhomogeneity.