Requirements for Sample Images for Mex 3D Software
EMS Catalog #MP-0101
Mex is a very easy to use package for the creation of 3D images for subsequent measurement with the SEM. The software will do nothing to correct faulty images nor will it allow you to see features that are not on the sample. But by following a few simple procedures the results will be both spectacular and contain significant data, these simple procedures are shown below.
- All images must be in TIFF or BMP format
- The magnification chosen must reflect the size of the features to be viewed; the software will not allow features to be measured that are not visible.
- Tilt Angle: Mex will take either 2 or 3 images and these are divided by tilt angle, the choice of 2 or 3 images is specimen dependent. In the first case please supply a pair of images which have a differential tilt angle of 5 degrees.
- Eucentric Tilt: Please ensure that the images are eucentric, this means that a single chosen spot on the image should be in the same position on each image (see note)
- Tilt Direction: Please ensure that the tilt direction, when viewed on the SEM screen runs East to West and not North South or diagonal. If images run at an angle this will result in image rotation which will reduce the size of the image that can be viewed.
- Working Distance. To construct the image we need to know the working distance
- Calibration: Please ensure that a scale bar is on the image.
To take images for MeX it is necessary to have Eucentric Images, it is not necessary to have a Eucentric Stage to take Eucentric Images. What is also important is that when tilt is applied the image moves east to west (or west to east) and not north to south or any diagonal from that.
A simple method without a Eucentric Stage is
1) Find and identify a feature on the image that can be used as a reference
2) Either turn on the cross wires built into the SEM or stick a corner of a post it note on the feature
3) Decide which magnification the image is to be taken at, then go 2 magnification steps above that and align the feature
4) Drop the magnification down and take the image
5) Reduce magnification to a level where the bulk of the feature is still visible (this makes it easier to track when tilt is applied)
5) Apply tilt bringing the feature back into the frame with X or and Y
6) Either turn on the cross wires built into the SEM or stick a corner of a post it note on the feature
7) Then go 2 magnification steps above the magnification selected in #3 and align the same feature
8) Drop the magnification down and take the second image
If a third image is required simply repeat the process
Details on image requirements are available in pdf format.