Veeco Dimension 3100, Руководство пользователя

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Calibration
Calibrating Z
Rev. D Dimension 3100 Manual 331
17.8 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 a metrology head employed with a Veeco Dimension Series
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.
17.8.1 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 .
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 Figure 17.8a ).
Figure 17.8a Z Calibration Image
5. Verify that the Z Center Position value shown next to the image display is close to 0 volts
( ±5 volts).