Instruction manual

Cantilever Preparation
Silicon Cantilever Substrates
Rev. B MultiMode SPM Instruction Manual 63
Figure 4.1f Common Silicon Probe Profile—Resultant Scan Artifact
Shown above in Figure 4.1f is the resultant effect of the angled back ridge on the step angle
measurement for a deeper trench depth. This will be tip and topography dependent.
The above discussions for Figure 4.1b–Figure 4.1f are in relation to microscopic scale shape
characteristics. There is one further detail which can come into play affecting the wall angle over
shorter (nominal 100nm) step height measurements: the shaped cusp at the end of the tip.
The shaped cusp at the end of the tip is formed to increase the sharpness of the point of the tip to a
length of 100nm from the end of the tip. It is formed in such a manner that the radius of curvature of
a silicon tip can be in the range of 5–10nm (on a very good tip).
S
can Line Profile
55°
70 - 80°
10°
1 µm - 2 µm Deep Trench
Note: Any wall angle on the left wall that is > 55 deg.
will be shown as 55 deg. in the image.
Any wall angle on the right wall that is >70-80 deg.
will be shown as 70 -> 80 deg. in the image.
Subsequent scan line produced by using
the realistic probe tip shape
11˚