High resolution electron backscatter diffraction with a field emission gun scanning electron microscope.

A scanning electron microscope with a thermal field emission gun (FEGSEM) is found to offer significant improvements in electron backscatter diffraction performance over a conventional W-filament scanning microscope. The spatial resolution is improved by a factor of approximately 3 in the FEGSEM and is optimized at probe currents of 50-300 nA and at 10-15 keV. The angular accuracy is optimized at probe currents above approximately 150 nA and at 30 keV.