Know your full potential: Quantitative Kelvin probe force microscopy on nanoscale electrical devices

Area of Science:

• Surface science
• Nanotechnology
• Materials science

Background:

• Kelvin probe force microscopy (KPFM) is vital for mapping nanoscale potential in electronic devices.
• Accurate potential measurements are key to understanding nanostructure operation.
• KPFM can suffer from artifacts like topography crosstalk and stray electric fields.

Purpose of the Study:

• To evaluate the influence of KPFM operation methods on potential distribution measurements.
• To compare the quantitative accuracy of Amplitude Modulation (AM) and Frequency Modulation (FM) KPFM.
• To assess the impact of stray electric fields on different KPFM techniques.

Main Methods:

• Utilized an interdigitated electrode array as a reference structure.
• Compared various AM-KPFM and FM-KPFM techniques.
• Measured the quantitative accuracy of applied voltage differences between electrodes.

Main Results:

• FM-KPFM methods generally yield more quantitative potential measurements.
• FM-KPFM results are less susceptible to stray electric field interference.
• AM-KPFM methods show greater susceptibility to imaging artifacts.

Conclusions:

• FM-KPFM is superior for quantitative surface potential measurements in electronic devices.
• Choosing the appropriate KPFM method is crucial for reliable nanoscale potential mapping.
• Understanding KPFM artifacts is essential for accurate device characterization.