The need for a rapid, non-destructive failure analysis of complex integrated circuits has led to the use of energy dispersive x-ray analysis (EDXA), to measure the localized thickness of Si02 and Al films on integrated circuits, by detecting the penetration threshold of the electron beam through the film. The accuracy (10%-20%) is determined by actual Scanning Electron Microscope (SEM) measurements, traceable to a secondary length standard, of the film thicknesses of sectioned samples. In contrast, another SEM based thickness measurement technique, such as Yakowitz-Newbury method, gave results that were 50-100% larger, required higher accelerating voltage that would damage the integrated circuit and took longer to setup/perform measurement. Typically, the thickness of the films range from 0.3 to 1.5 microns and thee-beam energy varies from 4 keV to 20 keV.
Sartore, Richard G.
"Measurement of Film Thickness on Integrated Circuits using Energy Dispersive X-Ray Analysis (EDXA),"
Scanning Microscopy: Vol. 1
, Article 5.
Available at: https://digitalcommons.usu.edu/microscopy/vol1/iss1/5