Hard-Core DIY Scanning Electron Microscope

Tyll Hertsens's picture

Back in the mid-'80s I was a field service engineer repairing scanning electron microscopes (SEMs) for Cambridge Instruments --- a now defunct maker of scientific instrumentation started by Charles Darwin's youngest son. I was based on the west coast and most SEMs I worked on were in semiconductor manufacturing facilities used for research and manufacturing inspection of integrated circuits. I ended up specializing in Dynamic Voltage Contrast Imaging, a very specialized use of SEMs where, because an electron beam is used, you can see the voltages change on integrated circuits. The beam can also stop scanning and be placed on any point on the integrated circuit and be used as an oscilloscope probe.

Fig 1. Voltage contrast image of integrated circuit. Darker traces have a more positive voltage than lighter traces as the more negative traces repel the negatively charged electrons more strongly.

Suffice it to say that an electron microscope is a complicated and touchy beast. We used to have a saying, "Why is a dynamic voltage electron microscope system like a fine English sports car? Because you don't want to start one up unless your mechanic is there."

Fig 2. Diagram showing the basic functional workings of a scanning electron microscope.

Electron microscopes are filled with myriad and dissimilar technological hurdles to overcome: high voltage adjustable power supplies; precise and adjustable analog scan generators; adjustable magnetic lenses; precise and finely adjustable mechanics for physically moving the sample; and optional complex systems like x-ray spectrometer analysis of specimen chemistry. SEMs are COMPLEX!

Well ... color me stunned when I ran across this guy who home built a scanning electron microscope! Wow! This is one cool DIY project.

I bow to his geekly awesomeness! For more from this amazing DIYer and his various and sundry DIY projects, visit his YouTube Channel.

Amazing! Thanks for the tip, ujamerstand!

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