User`s guide

Scanner Maintenance and Calibration 8
Agilent 5500 SPM User’s Guide 142
movement) and a single tube for Z motion. Since the range is small with
these scanners, the effect of cross-coupling is minimal.
Aging
Aging is a time-dependent effect in which the sensitivity (extension per
unit of field) of the scanner decreases, approximately exponentially,
over time. A large amount of decrease takes place during the first few
hours of use. Therefore, scanners are burned in before initial calibration.
After this initial burn-in, the aging rate is very slow; however,
calibration once or twice per year is still recommended.
Creep
At a constant applied voltage the piezo position will change slightly
over time, most noticeably at the beginning of a scan or after a change
on scan location. Creep appears as elongation of the feature in the
direction of the offset because of this slow movement (Figure 93).
Figure 93 Scanner creep