Offline Operation
Rev. F
Scanning Probe Microscope Training Notebook
47
Bearing
Bearing ratio determination and depth histogram measurements are possible with Bearing.
Bearing provides a method to analyze how much of the surface lies below or above a given height.
The “bearing ratio” of the surface is the percentage of the surface at a specific depth with respect to
the entire area analyzed. (See manual for further description)
The depth histogram plots depth versus percentage of occurrence of data at different depths.
By enabling the Histogram Cursor (top menu, display screen), two cursors are available on the
histogram to make relative depth measurements.
Area depth measurements can be made by placing the two cursors at peaks representing different
feature heights. The area depth measurement can be made by determining the relative depth
between the two cursors.
•
Planefit and/or Flatten may need to be performed before making this measurement. This
will produce sharper peaks in the depth histogram.
The
Depth
feature may be used to make automated depth histogram measurements over many
images. (See manual for details)
Figure 18.2c
Area Depth Measurement of GaAs Lines using the Bearing Histogram
18.3 Filters
There are a wide range of modification functions found in the Modify menu that may be applied to
an image once it has been captured. These functions are explained in detail in the Command
Reference Manual.
It should be kept in mind that by using any modification functions, the data is being changed which
may or may not affect the measurements of interest. In general, it is good practice to modify the
image as little as possible, and to understand how the applied function will affect the image and
measurements.
