Any specimen, whether it has been sputter coated or is naturally conductive, must be firmly attached to the specimen support before being viewed in the SEM. Attention to detail in the mounting proceedure is very important if a researcher desires a quality result.
Non-conductive samples
Make sure the support (specimen stub) is clean before use and also check to make sure the stub you are using is compatible with the stage of the SEM you will be using.Place the specimen on the stub before the sputter coating procedure. This will increase the conductivity and therefore the quality of your results.
Conductive samples
The specimen stub you choose should be of a material that will not interfere with the backscattered-electron and x-ray signals that will be emitted from the specimen. Again, make sure the stub is clean and compatible with the SEM you are using.
Additional Notes
For some samples it will be necessary and perhaps more convenient to place the specimen on a substrate that will be mounted on the stub. Substrate materials range from glass and plastic cover slips to metal and crystalline disks, plastics, waxes and many membrane filters. Since it is frequently necessary to attach the specimen or substrate to the stub, a variety of adhesives is available for this purpose. You should make sure to choose an adhesive that will not decrease the quality of your results.