Veeco Dektak 150, User Manual

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3D Mapping Function E-7
Checking Stylus Operation after Calibration
With soft touchdown enabled, watch the stylus as it finishes a scan and the stage moves to next scan
location. The stylus should be slightly below its balance point, and you should see it gently bobbing,
but not touching the surface.
When the stylus engages, it should come down smoothly, and then slow as it nears the surface and
gently come into contact.
Troubleshooting Soft Touchdown Problems
The following strategies can help solve soft touchdown problems:
•
If the stylus does not pick up at the end of the scan, repeat steps 1 - 3 in the previous section. If
it still does not pick up, decrease the Initial and Lift Off Force values in increments of 100 DAC
counts until stylus operation becomes smooth.
•
If the stylus comes down forcefully after a long pause, repeat steps 1 -3 in the previous section.
If it still comes down too forcefully, increase the Initial and Lift Off Force values in increments
of 100 DAC counts until stylus operation becomes smooth.
•
If the stylus comes down smoothly at first, but then contacts too quickly at the end, either
decrease the Engage force increment or increase the delay.
•
If the stylus bobs dramatically as it engages, decrease the Initial Force value and increase the
delay.
As you troubleshoot, bear in mind the following:
•
Soft Touchdown is automatically enabled with N -lite forces.
•
Soft Touchdown cannot be used with Tower Up after Scan operation.
•
Although Soft Touchdown cannot be used in Hill mode, it can be used in both Valleys and Hills
and Valleys modes.
ENTERING SOFT TOUCHDOWN INTO A SCAN ROUTINE
NOTE –
The Soft Touchdown option is available only when the Map Scan scan type is
selected and the Tower Up After Scan option is NOT selected.
WARNING
Movements that are too forceful can result in damage to the stylus and/or the
sample.