TEM Specimen Preparation Technique For Small Semiconductor Devices

Extract

One of the methods of preparing samples for analysis by Transmission Electron Microscopy (TEM) is the well-known procedure using a Tripod polisher and the wedge technique (1-3), developed in our laboratory. Though developed explicitly for preparing samples of integrated circuit structures built on silicon, the technique has been used in our lab for a wide variety of other materials, including metals and ceramics. In general when working with silicon samples, we have the luxury of starting with large wafer pieces or chips that are generally at least a couple of millimeters square or larger. Recently, however, we needed to work for an extended period on GaAs based lasers, where the devices requiring analysis were individual lasers extracted from individual packages. These small samples, measuring 100x100x50 microns, are too small for the manual handling involved in routine mechanical cross sectioning methods.