Tip Shape Issues
Rev. F
Scanning Probe Microscope Training Notebook
57
Vertical Resolution Issues
Scanner
:
•
Since the resolution in the vertical direction is not determined by the tip shape, it is
primarily determined by the resolution of the vertical scanner movement which is <1Å.
Pixelization
:
•
As in the lateral dimension, the number of data points in the vertical direction limits the
size of the smallest resolvable height change.
•
The number of data points in the vertical dimension is determined by the conversion of
16 bits over the full vertical range of the scanner (440V).
•
The Z-limit parameter may be used to increase the sampling resolution in the vertical
dimension to image sub-angstrom height changes with large Z range scanners.
Noise
:
•
The overall system noise will generally be the primary limiting factor in the highest
obtainable vertical resolution that can be acquired with your SPM. This may be a result
of combined effects from electrical, mechanical, and acoustic noise sources.
•
Bruker guarantees 0.3 to ~1Å RMS noise levels depending on the type of SPM and
SPM environment.