AFM Artifacts

by Peter Eaton

2. Other Artifacts

Flying Tip

This artifact shows that the AFM is not properly tracking the surface.
In the example below, it is obvious, but this is not always the case.
Sometimes it is clearer if you look at some of the other signals, like amplitude or phase or deflection images.
IN this case, note how all the features have a "tail" to their left.
AFM image showing poor feedback

In the example above, the image of nanoparticles shows "tails" on each particle, to the left. The image was recorded right to left.
Commonly the left to right image would show the tails on the right side of each feature. It is typical of this effect, that you will get different images in the two directions.

How to avoid it.
If you see this, your feedback parameters are incorrect.
It is usually easy to fix. You generally should increase integral gain, then proportional, you may need to change the setpoint too, or even scan more slowly.

Artifacts Index Page
This document was written by, and is maintained by Peter Eaton (
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Document updated on 14th September 2007.