The continued development of commercial STEM systems in the next few years will have a dramatic impact on all aspects of electron microscopy, particularly as the resolution improves. The STEM system offers us the opportunity for direct computer analysis of image signals of all types, wherein signals produced by characteristic X-rays, photons, electrons will be used in a variety of mixes to produce micrographs of thin films. For example, because larger areas and thicker films can be examined in STEM systems compared to CTEM scopes, it will be commonplace to examine sections of thickness cut for OLM transmission work in the STEM. It will also become increasingly important to produce micrographs of matched internal and external structure; that is, internal structure examined by STEM signals and external structure via SEM topographical signals (secondary and backscatter emission). The examination of thin films in the SEM mode however presents some difficulties in that the depth of penetration of the primary beam is a function of the accelerating 1 voltage (roughly according to where k' and n depend on the material).
Study on Modification of SiO2 Thin Film Surface Morphology and Its Electrical Performance