nGauge AFM User Manual
12
In the Approach tab, click the
Approach
button to initiate the auto-approach. The sample
platform will rise quickly and then slow down for a final approach once the sample gets very close. The
data being streamed on the graph represents the cantilever oscillation amplitude, and it will begin to
decrease as the sample gets close and tip-sample interaction is observed. When the auto-approach is
complete, the tip will be engaged with the sample and you can proceed to imaging. If the cantilever
oscillation amplitude does not track the setpoint or the amplitude oscillates, please refer to section 6.0
Troubleshooting.
4.3 Imaging
In the
Scan
tab, choose the image resolution you would like by selecting the
number of pixels
per line
and the
number of lines
per image. The higher the resolution, the longer it will take to complete
a scan. The
Time spent at each point
field indicates the amount of time that the tip dwells above each
point of the scan and ultimately determines the scan speed. A smaller number in this field increases the
scan speed, but if the scan is too fast the resulting image may be blurry or distorted.
Click
Scan
to begin imaging. The image will begin to build up line by line. The color in the image
represents the height of the features, and some minor corrections (line leveling, plane leveling) can be
applied to the raw data to display a clearer image by checking the
Level Image
checkbox on the left side
of the screen. There you will also find the options to display the topography, phase, or error images in
both the forward and reverse directions. A profile view can be found below the image that displays the
cross-section (height) of the current line being scanned. When the scan is completed, the line under
your cursor would be displayed on the line profile plot. You can widen or narrow the line profile by using
the scroll wheel.
The Z actuator is split into Coarse Z and Fine Z controls. The Fine Z has a smaller range, and it’s
the control that is used to track sample topology while scanning. If a sample has tall features that extend
