Adjust The Detector Offsets And Setpoint (Contact Mode); Engage The Surface; Adjust Scan Parameters (Contact Mode) - Veeco 004-210-000 Instruction Manual

Fluid Operation
General Fluid Operation

8.2.7 Adjust the Detector Offsets and Setpoint (Contact Mode)

Adjust the detector mirror adjustment screws:

8.2.8 Engage the Surface

1. Using the Motor down switch (and coarse adjustment screws if not using a vertical engage
scanner), lower the tip until it is just above the level of the sample surface.
2. In the Real Time > Motor menu, click Engage, or click the Engage icon.

8.2.9 Adjust Scan Parameters (Contact Mode)

1. Once engaged, adjust the scan parameters to obtain the best image.
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In Contact Mode (i.e., Other Controls > Microscope mode set to Contact and
Feedback Controls > SPM Feedback set to Deflection), to achieve a vertical
deflection signal of roughly -1.0V. Set the Feedback Controls > Deflection Setpoint to
0V to begin.
•
The difference between the vertical deflection signal before engaging and the setpoint
determines the amount of force that the probe applies to the sample.
•
Typically, samples are softer in liquid than in air. Before engaging, verify that there is
not so large a difference between the setpoint and the vertical deflection signal as to
damage the sample.
•
Verify reasonable values for scan parameters (e.g., Scan rate, Scan size, Integral gain
and Proportional gain).
•
Once engaged, reduce the setpoint to minimize the tracking force.
•
The Motor down switch is located on the MultiMode base.
•
Watch the engagement closely through the 25× magnifier or using the vertical optical
microscope.
•
The motor begins to move the AFM head and probe down to the sample.
•
When the tip reaches the surface, the system should automatically stop, beep, and begin
to image the sample.
•
In Contact Mode, if the system engages immediately or before the tip reaches the
surface, try increasing the Setpoint approximately 2.0V, then repeat this step.
Note: This procedure is similar to operation in air, except that samples are often softer
in fluid. Adjusting the applied force can be critical.
MultiMode SPM Instruction Manual Rev. B