Reduction of electrical damage in specimens prepared using focused ion beam milling for dopant profiling using off-axis electron holography.
GaAs specimens containing p-n junctions have been prepared using focused ion beam (FIB) milling for examination using off-axis electron holography. By lowering the FIB operating voltage from 30 to 8 kV, we have shown a systematic reduction of the electrically 'inactive' thickness from 220 to 100 nm, resulting in a significant increase in the step in phase measured across the junctions as well as an improvement in the signal-to-noise ratio. We also show that the step in phase measured across the junctions can be influenced by the intensity of the electron beam.
Cooper
David
D
CEA LETI - Minatec, Grenoble, Cedex 9, France. david.cooper@cea.fr
Truche
Robert
R
Rouviere
Jean-Luc
JL