SEM-EDS Depth of Information

Elemental composition results from EDS survey spectra and XPS survey spectra are usually very different because XPS measures only the top 10 nm, while EDS measures 300 nm to 5,000 nm below the surface.

EDS is true Bulk Information.  XPS is true Surface Information. SEM images are from the top 5-10 nm, but SEM images do not contain any chemical information.

XPS can be used to analyze true bulk of a sample by fracturing the sample to expose true bulk.


XPS Information comes from Top 10 nm – Green Disk at Top


SEM-EDX Information depends on Voltage Used – See Calculated Depths of Information Chart below. 


Monte-Carlo simulations based on a 1,000 nm depth, which is 100X deeper than XPS depth.