Scanning tunneling microscopes are relatively easy, scanning electron microscopes (with an electron beam) are a lot harder (if you want any kind of serious magnification).
Getting some results appears to be doable but before you get the resolution and repeat accuracy of a commercial model I think you'll be spending the same amount of money. But you'll learn a ton :)
An STM uses a needle that is only a few atoms across to scan the object under inspection, an SEM uses an electron beam to do the same in a high vacuum chamber.
An STM you can build under $100, an SEM would at a minimum cost you several thousand (and much more if you can not do your own machining).
Getting some results appears to be doable but before you get the resolution and repeat accuracy of a commercial model I think you'll be spending the same amount of money. But you'll learn a ton :)
An STM uses a needle that is only a few atoms across to scan the object under inspection, an SEM uses an electron beam to do the same in a high vacuum chamber.
An STM you can build under $100, an SEM would at a minimum cost you several thousand (and much more if you can not do your own machining).