Plasma Cleaning for Electron Microscopy

Abstract

Specimen contamination and amorphous irradiation damage severely limit the ability to perform accurate electron microscope analysis of materials, especially as specimen areas of interest decrease in size. To analyze smaller areas of interest, electron probe sizes have decreased, while probe currents have increased. The combination of these two factors results in an increase in the amount of carbonaceous contamination formed on the specimen under the electron beam. Recently, the use of low energy plasmas has been shown to be effective in preventing such contamination from occurring (1-3). For TEM, the simultaneous placement of the specimen holder and specimen into such a plasma for short periods of time (usually less than two minutes) results in the ability to hold a converged probe on the specimen for analysis without contamination becoming an problem. Figure 1 is a TEM micrograph of a 304 stainless steel specimen.