Summer REU student participate in a short course to learn the basic concepts of electron microscopy and microanalysis. Participants gain practical experience operating either a scanning electron microscope (SEM) or a focused ion beam microscope (FIB), depending on what will best serve them in their research efforts. The faculty mentors' labs are well equipped and participants will also gain experience on a variety of equipment depending on their area of research.

Scanning Electron Microscope (SEM)

The SEM is one of the most versatile instruments available for the examination and analysis of the microstructural characteristics of solid objects. It provides two outstanding improvements over the optical microscope: it extends the resolution limits and improves the depth-of-focus resolution dramatically (by a factor of ~300). It is also capable of examining objects at a high range of magnifications. This feature is useful in forensic studies as well as other fields because the electron image complements the information available from the optical image.

Focused Ion Beam Microscope (FIB)

The Focused Ion beam (FIB) uses a stream of Ga ions to image or mill the surface of a sample. Operating much like an SEM, the beam of ions is raster scanning over the surface of the sample with a variable width, speed, and intensity. The Ga ions can have an energy of 5-30 keV. High energy intensities cause the surface of the sample to be milled or sputtered away; the milling process is similar to shooting a shotgun at a brick wall. Typical beam currents range from 50 pA to 5 nA. Beam diameters can range from 5 nm to more than 1 micron. Various secondary signals such as, ions, electrons, and X-rays can be generated from the sample when Ga ions impact the sample.