Artifacts in SPM Imaging

Scanning probe microscopes use piezoceramic elements to control the motion of the probe or sample on the nanometer scale (see Section 3.3.1.3). In scanned tip systems the cantilever/ probe is attached to the scanning element. In scanned sample systems the sample is attached to the scanning element. Scanner-related artifacts arise from two sources  

Non-ideal behavior of the piezo elements in their response to applied voltage. There are 

Non-ideal motion of the scanner due to coupling of motion between the axes. 

The response of a piezo to a large step change in voltage is not a step change in position. Most of the motion occurs very quickly, but then there is a slow continuing motion, called creep. This means that after a rapid change, the tip position will not be stable until the creep is 

Any finite-sized probe must cause an apparent increase in size of small protruding objects and an associated apparent reduction in size of pits. 

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