Quantitative material analysis using secondary electron energy spectromicroscopy

Area of Science:

• Materials Science
• Surface Science
• Spectroscopy

Background:

• Scanning electron microscopy (SEM) is a common tool for surface imaging.
• Quantitative analysis of material properties at low beam voltages is challenging.
• Secondary electron (SE) signals in SEM contain rich information about material composition and electronic structure.

Purpose of the Study:

• To demonstrate the capability of secondary electron energy spectroscopy (SEES) for quantitative material analysis in low voltage SEM (LVSEM).
• To show SEES can map sample atomic number and determine bulk valence band density of states (DOS).
• To validate the accuracy and potential applications of SEES in conjunction with SEM and Scanning Auger Microscopy (SAM).

Main Methods:

• Utilized an electron energy analyzer attached to a SEM.
• Detected subtle spectral shape changes in scattered secondary electron (SE) signals.
• Extracted fine structure features from SE spectra to derive material properties.

Main Results:

• Achieved accurate mapping of sample atomic number.
• Successfully acquired bulk valence band density of states (DOS) information.
• Demonstrated close agreement between experimental and theoretical DOS distributions for six test samples (2.7–6.7% normalized root mean square deviation).

Conclusions:

• SEES is a viable quantitative analysis tool for LVSEM.
• The high accuracy achieved by SEES opens new avenues for material characterization.
• SEES can enhance the capabilities of existing SEM and SAM instruments for advanced analysis.