Scanning Transmission Electron Microscopy (STEM)
STEM is similar to TEM. The difference is that the electron beam scans the sample in a raster while the electron beam is focused on a small spot. Equal to TEM the different ways of interaction of the electron beam with the specimen is used to create an image. The spot-size of the electron beam needs to be 1nm or less which is only possible by using an Field Emission Gun.
The basic imaging methods of STEM are similar to the ones of TEM, but one of the most interesting advantages of STEM is the possibility to use different imaging modes at the same time which is not possible for TEM.