Calibration, Maintenance, Troubleshooting and Warranty
SPM Calibration Overview
Rev. B
MultiMode SPM Instruction Manual
275
15.1
SPM Calibration Overview
Veeco employs a software-guided calibration procedure for all its microscopes. The procedural
particulars of how calibration is executed using NanoScope software are beyond the scope of this
document and include proprietary methods exclusive to Veeco. The calibration procedure is
summarized in the following four basic steps:
Note:
For a brief overview of the theory behind calibration, please see
1.
Orthogonality
: The orthogonality adjustment compensates for a possible non-square scan
pattern.
2.
Scanner Linearization
: Adjust parameters for correcting the capacitive nature of the piezo
material and force the X-Y motion of the tip to move at a constant velocity.
3.
X-Y Calibration
: Designate the software conversion values using one or both of the
following methods.
•
Capture Calibration
and
Autocalibration
: A built-in software routine automatically
controls the scanner while capturing a series of data
fi
les. The data
fi
les are then used to
“teach” the software the actual distance that the scanner moved. This process creates a
customized set of conversion values that will be used to convert the known signals to a
metric scale.
-or-
•
Fine-tuning
: Manually test and adjust X-Y sensitivity and derating values to within 1%
accuracy. The conversion values that scale the scanner motion are con
fi
rmed or are
adjusted, if needed, to within 1%. These same values should be adjusted by the customer
as the scanner ages due to use. A scanner will typically lose 10-20% of it’s scan range
over the
fi
rst year of typical use. The scanner will then become stable as long as it is not
damaged.
4.
Calibrate the Z scan tube to within 2%
: A separate calibration reference table stores the
conversion values for converting the control voltages applied to the Z tube. These values are
determined by scanning over a sample with a known depth.
