The scanning electron microscope as a means of investigating "Second breakdown" and similar phenomena

This paper illustrates the ability of the scanning electron microscope to contribute to the understanding of breakdown phenomena. In particular, we stress the use of this instrument as a very fine probe with an ability to make high resolution "maps" of the charge collection efficiency of a diode, and to detect very small regions of avalanche breakdown. By means of recently obtained pictures, the voltage sensitivity and spatial resolution of this technique is discussed. The range of experimental conditions over which this method can be used is described. The inherent limitations and the possible extensions are also given. Finally, the application to "second breakdown" is suggested.