Calibration, Maintenance, Troubleshooting and Warranty
Calibrating Z
Rev. B
MultiMode SPM Instruction Manual
299
15.8
Calibrating Z
In terms of obtaining accurate Z-axis measurements, it is generally not dif
fi
cult to obtain accurate
X-Y calibration references. However, it is much more dif
fi
cult to obtain accurate Z-axis results. Z-
axis calibration is very sample-dependent. It is dif
fi
cult to control Z piezo dynamics because the Z-
axis does not move at a constant rate, as the X- and Y-axes do during scanning. Furthermore, offsets
affect the piezo over a period of minutes. The silicon calibration references distributed by Veeco
have 200nm vertical features accurate to within ± 3 percent. The calibration reference is referred to
throughout the examples provided in this section. If you require greater accuracy, you must select
an appropriate calibration standard and/or a metrology head employed with a Veeco MultiMode
microscope.
Note:
Refer to the label on your calibration reference sample to verify the
measurement employed is 200nm. Older systems may have samples with a
different Z value.
15.8.1
Engage
1. Set up the microscope for
TappingMode
imaging.
2. Select
Engage
under the
Motor
pop-down menu or click on the
ENGAGE
icon.
3. Find a square pit and center the pit in the image using a
Scan size
of approximately
10µm
.
Note:
For “A” scanners you will only be able to image a small portion of one pit.
Adjust the sample and/or microscope stage until one side of a pit is visible,
along with portions of the
fl
at area around the periphery of the pit. If you have
problems locating a pit, please refer to
Finding a Pit with an “A” Scanner:
4. Change the aspect ratio to 4:1, and verify that the image includes the pit along with portions
of the surrounding flat area (see
