What size features would you be looking to image? STM typically is used for atomic resolution imaging, so the maximum practical field of view is probably in the 10s of nanometers if you have atomistic resolution.
You might be better off with SEM if you need much larger field of view and can live with the coarser resolution limit
You might be better off with SEM if you need much larger field of view and can live with the coarser resolution limit