A Comparative Study of AFM between AM KPFM and Sideband KPFM  

Principles and Applications

This study analyzes three different samples to compare the electrical resolution performances of AM-KPFM and Sideband KPFM. In the conventional method, amplitude modulation (AM) KPFM, the measurement signal directly relates to the electrostatic force between sample and tip via the amplitude of the AC frequency signal.

 

This implies that AM-KPFM is strongly affected by the AFM cantilever, which lowers the resolution and sensitivity due to an averaging effect. The Sideband KPFM method has an advantage in terms of the spatial resolution and sensitivity of the surface potential measurement compared to AM KPFM.

The results of this study demonstrate that Sideband KPFM has superior spatial resolution and potential sensitivity compared to AM-KPFM. In surface potential images, Sideband KPFM shows a clear electrical contrast and detects relatively small potential images.

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