Scanner Maintenance and Calibration
5
Keysight 5500 SPM User’s Guide
5-5
explained below. Though they are explained separately for simplicity,
they may not be independent of each other.
All Keysight scanners are calibrated before shipment and installation. A
unique calibration file is provided with each system, as is a “generic”
calibration file, which is not scanner-specific.
Non-Linearity
shows a calibration target consisting of square features of
known size and equal spacing. The image was made with an
uncalibrated scanner. Features are larger at the start of each scan line,
and also at the bottom of the image. This effect is the result of
non-linearity of the piezo response across the scan range.
Figure 8-1
Image from an uncalibrated scanner showing non-linearity
Sensitivity
The features in
also change size within each scan line.
Lateral feature sizes may be reported incorrectly due to changes in piezo
sensitivity.
Hysteresis
Hysteresis is an effect in which the piezo movement during extension in
one direction does not match the movement during contraction caused
by an equal and opposite field in the other direction. The effect of