The Secondary Electron Emission Characteristics of Carbon Materials

Abstract

  The secondary electron emission characteristics of various carbon materials have been studied using a conventional scanning Auger microscope (SAM) and a specially designed sample holder with a Faraday-cup attachment. In previous investigations using this technique, we confirmed that the secondary electron emission coefficient δ was largely dependent on the surface composition [J. Surf. Anal. 11, 71 (2004)]. The present study examined the secondary electron emission characteristics of carbon materials having various surface structures, with the same surface composition. The results clarified the following points. (1) δ of all the carbon materials examined was small in comparison with other materials, suggesting that they have an effect of restraining secondary electron emissions. (2) The change in δ due to an increase in surface roughness varied between the low and high regions of primary electron energy. (3) δ was not dependent on the substrate at a depth below 200 nm. In evaluating δ, it should be kept in mind that δ is affected by not only the surface composition but also the surface structure, orientation, and surface roughness of the material.