Final answer:
The scanning electron microscope (SEM) uses a fine metal coating on the specimen to produce a 3D image of the surface.
Step-by-step explanation:
The type of electron microscope in which the specimen is sprayed with a fine metal coating to produce a 3D image of the surface is called the scanning electron microscope (SEM).
The SEM uses secondary electrons produced by the primary beam interacting with the surface of the sample. It moves the beam around electrically to "scan" the sample and uses a CCD detector to process the data and create a 3D image.
By spraying the specimen with a fine metal coating, the SEM is able to enhance the details of the surface and provide a more accurate representation of the sample.