Electron-Beam-Induced Currents in Semiconductors

Abstract

The scanning electron microscope (SEM) is an extremely versatile instru­ ment capable of yielding many different kinds of information from the resulting interaction of the electron beam and the sample. One such interaction produces currents in semiconductors, the topic of interest here. The popular acronym for this subject is EBIC (electron-beam­ induced current). The EBIC technique can, among other things, be used to directly image recombination sites; to measure transport properties such as minority carrier diffusion length, lifetime, and surface recombina­ tion velocity; to determine junction depths and shallow trap energy levels; to image inversion layers in integrated circuits; and to map leakage paths and microplasma sites. There exists in the literature, however, a lack of clarity regarding the interpretation and basic accuracy of some of the above measurements. Our aim in this article is therefore twofold: to clarify this situation through reviewing the limits and applica­ bility of the various models, and to explain the technique itself and discuss examples of its application, power, and limitation.