Step height accurate in the nanometer range?

Hi, I recently took some step height measurements with results in the 9-15 nm range. Is the profilm3D really that accurate at nanometer ranges that they can be reported or should it be used as a proportion only?

Here is an example of the step height measurement.


Hello FSabri,

The Profilm3D (in my hands) has successfully measured a VLSI 9nm step height standard. So it is possible to trust measurements in this regime. This assumes that your instrument is measuring it’s 10um standard correctly. For your sample I would do SEM/FIB and see how they agree if you want to improve your confidence.


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The P3D has three measurement modes: WLI, GLI, and PSI. The PSI mode will give the best height resolution but works only for samples where the height variation between neighboring pixels is always less than approximately 150 nm. This appears to be the case for your sample.

If you haven’t already, you should explore using the PSI measurement mode. Also, you should consider whether the surface materials are the same in both high and low regions. If they are different, you should select the “Dissimilar materials” option (in Step 3 of the Step Height Line or in Step 2 of the Step Height Rectangles). This will apply a correction that compensates for the fact that light when reflected from an interface changes its phase differently for different materials.

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Hi, this is not exactly related with the main topic, but I’m just starting to use this system and I’m not even able to change from WLI to GLI or PSI, is it necessary to have an additional hardware or the options are disable because of the height variation of neighboring pixels? I’m interested on measure a groove similar to this one, but my measurements have too many invalid points.

Hi Gonzalo,

GLI and PSI require special licenses to use. Do you know if you have those licenses included with your Profilm3D? If you do not or are unsure, then I would suggest reaching out to one of our application engineers with your serial number for help. You can find a link to contact our team here!