Calibrating Z; Engage - Veeco 004-210-000 Instruction Manual

15.8

Calibrating Z

In terms of obtaining accurate Z-axis measurements, it is generally not difficult to obtain accurate
X-Y calibration references. However, it is much more difficult to obtain accurate Z-axis results. Z-
axis calibration is very sample-dependent. It is difficult 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:
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
3. Find a square pit and center the pit in the image using a Scan size of approximately 10µm.
Note:
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
Rev. B
Calibration, Maintenance, Troubleshooting and Warranty
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.
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 flat area around the periphery of the pit. If you have
problems locating a pit, please refer to Finding a Pit with an "A" Scanner:
Section 15.8.7.
Figure
MultiMode SPM Instruction Manual
15.8a).
Calibrating Z
icon.
ENGAGE
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