Metrology using scanning probe microscopy

The use of the AFM as a probe of surface topography at a resolution of several nanometers 

There are several image artifacts that may make the image an inaccurate representation of the surface [151]. The most important of these is 

This problem exists at any resolution, but at these low resolutions of more than a few nanometers the tip shape is stable and measurable. Tip shape can be measured by observing the image of a known shape, and can be relied on to stay the same for a reasonable time. Latex 

If rough surfaces are to be measured, then a tip shaped like a needle will have fewer problems than a pyramid or cone, even if the cone has a very small radius at the tip. Tips of this form are made by etching away material from a standard tip, or adding a thin spire to it by electron beam assisted chemical vapor deposition (CVD), and are available commercially. These can probe deep and narrow trenches, but they are more easily 

These problems, though important for accurate measurement of feature size, should not be allowed to hide the fact that the AFM can show detail and make accurate measurements at the 5 nm level with little or no specimen preparation. The results compare well with high resolution LVSEM, as shown in Fig. 5.58. The AFM is not only cheaper, but allows in situ environmental studies without the problem of vacuum or 

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