A Technique to Prepare Cross Sections of Semiconductor Devices in Small Samples for Transmission Electron Microscopy

Extract

This technique is used to prepare cross sections of semiconductor devices in small samples for analysis by Transmission Electron Microscopy (TEM). These small samples, measuring 100 X 100 X 50 microns, are too small for the manual handling involved in routine mechanical cross sectioning methods. A larger sample, for easier manual handling, is made by gluing the original small sample between a larger piece of silicon and a larger piece of dimpled quartz. The dimpled depression in the quartz is just large enough to surround the original sample. The sample is then mechanically thinned down using a Tripod polisher and the wedge technique. The quartz piece, glued to the top of the original sample, allows the progress of the polish to be monitored as the first side of the cross section is being mechanically polished. The silicon piece, glued to the bottom of the original sample, is used to gauge the final thickness of the wedge produced when polishing the second side of the cross section using the wedge technique.