VARIABLE-DEPTH ELECTROPOLISHING OF TEM SAMPLES

A variable-depth electropolishing technique has been developed for tra nsmission electron microscopy samples using copper as sample material. This was required for an experiment concerning the measurement of the variation of dislocation density with depth for ion-implanted materia ls. The polishing technique was achieved by a two-step process, involv ing the measurement and use of the polishing rate to polish to a speci fic depth and the application of a transparent cover to one side of th e sample for back-thinning. With this technique, any sample depth can be made accessible for observation with a transmission electron micros cope and the method should be applicable to many different materials a nd electropolishers.