Specific Process Knowledge/Characterization/SEM: Scanning Electron Microscopy/samplemount: Difference between revisions

From LabAdviser
Jmli (talk | contribs)
Jmli (talk | contribs)
Line 14: Line 14:
: Finding the right feature on a sample is more tricky than one would think due to the limited field of view. Making sketches of feature positions on the sample or drawing on the sample itself is often a great help.
: Finding the right feature on a sample is more tricky than one would think due to the limited field of view. Making sketches of feature positions on the sample or drawing on the sample itself is often a great help.
; Limit cross contamination issues
; Limit cross contamination issues
:  
: Sticking your sample onto carbon pad that is already sitting on a pin stub is a very fast way to get started - but it is not a very clever one. Using old carbon pads has many disadvantages:
; Optimize imaging conditions
* The electrical conductivity of the carbon pad degrades over time and you will have charging problems
: Poorly mounted samples are much more likely to vibrate or charge up.
; Optimize imaging conditions hence image quality.
: Poorly mounted samples are much more likely to vibrate or charge.


Respect the guidelines on sample mounting in the next sections and you will maximize the results of your efforts at the SEM.
Respect the guidelines on sample mounting in the next sections and you will maximize the results of your efforts at the SEM.

Revision as of 13:36, 17 June 2016

Why is sample mounting so important ?

Sample mounting is much more important than many SEM users seem to think. If you can get away in 10 seconds with fixing the sample to a sample holder so that it will not fall off during the SEM session, the sometimes precious time that you have on the SEM is better spent operating the instrument - right? Well, not quite. In case you are in doubt, this page will explain you why.

Consider the benefits of a correctly mounted sample:

Safety of the instrument
A poorly mounted sample may encourage users to put the stage in a position that, in order to be able to take an image, puts the instrument health at risk - this must always be avoided.
Accessibility
You can 'access' the sample in a way that enables you to take the images you need: If, for instance, short working distance is needed to ensure optimum conditions for the Inlens detector, the sample must be mounted in a way that makes it possible.
Problems with charging are minimized
In most cases where users complain that the sample seems to be drifting they tend to blame the stage. The reason is always bad grounding of the sample due to sloppy mounting.
Limit the waste of time
Finding the right feature on a sample is more tricky than one would think due to the limited field of view. Making sketches of feature positions on the sample or drawing on the sample itself is often a great help.
Limit cross contamination issues
Sticking your sample onto carbon pad that is already sitting on a pin stub is a very fast way to get started - but it is not a very clever one. Using old carbon pads has many disadvantages:
  • The electrical conductivity of the carbon pad degrades over time and you will have charging problems
Optimize imaging conditions hence image quality.
Poorly mounted samples are much more likely to vibrate or charge.

Respect the guidelines on sample mounting in the next sections and you will maximize the results of your efforts at the SEM.