Scanning Electron Microscopes: Is High Resolution Possible?
Experiments with this scanning microscope have produced extremely encouraging results so that we feel Confident in predicting high resolution and high contrast after some obvious modifications are made in the system, such as providing a good objective lens. Experience with conventional lenses indicates that the instrument behaves in a predictable manner and there is no reason to doubt that the resolution can be as good as that of a conventional microscope. The use of quadrupole lenses will depend on calculations now being performed. There is cause for optimism; high resolution may also be possible with this kind of lens. Experience with field emission shows that the technology is not difficult and that there is more than enough current available for any conceivable use. Energy-loss measurements have been made on a variety of materials. It is attractive to consider the possibility of chemical analysis of selected areas of a specimen. We believe that a very crude form of analysis may ind
