Improved TEM samples of semiconductors prepared by a small-angle cleavage technique.

A small-angle cleavage technique has been developed that produces superior transmission electron microscope (TEM) samples of semiconductors and related materials. The technique involves back-thinning the sample to approximately 100 microns, then scribing a groove on this back face at a specified small angle to a standard cleavage plane. The sample is cleaved along this scribe line followed by cleaving along the standard cleavage plane to produce a thin wedged sample. Samples prepared by this method are characterized and compared with conventional and low-angle ion milled samples. The technique is illustrated, and the characteristic geometry of the cleaved sample is explained in terms of a simplified cleavage model.