A technique has been developed which enables one to cross-section specific devices or features for examination with the scanning electron microscope (SEM). This method is used for investigation of all facets of microelectronic circuit manufacture from research and development to failure analysis of the finished product.
Selective etching is used to provide contrast to each processed layer. Etch type and sequence, used for delineation, are important to understand since they may add artifacts to the cross-section, leading to erroneous analysis conclusions. The etchant and etch conditions used will be dictated by the information needed from a particular sample.
Etching systems based on HF-HNO3-H2O are used with metal oxide semiconductor (MOS) technologies. In addition, buffered silicon dioxide etches are also used especially to delineate silicon dioxide layers.
Cross-sectional analysis enables measurement of processing parameters such as junction depth, channel length, layer thickness and length, layer composition and step coverage.
Koellen, Daniel S.; Saxon, David I.; and Wendel, Kenneth E.
"Cross-Sectional Analysis of Silicon Metal Oxide Semiconductor Devices Using the Scanning Electron Microscope,"
Scanning Electron Microscopy: Vol. 1985
, Article 5.
Available at: https://digitalcommons.usu.edu/electron/vol1985/iss1/5