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Improvement of crater‐edge profiling for the characterization of superlattice structures
Author(s) -
Sobue S.,
Tanemura M.,
Okuyama F.
Publication year - 1989
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.740140805
Subject(s) - superlattice , impact crater , materials science , stacking , molecular beam epitaxy , characterization (materials science) , ion milling machine , zigzag , optics , epitaxy , layer (electronics) , chemistry , optoelectronics , geometry , nanotechnology , physics , organic chemistry , astronomy , mathematics
An Auger crater‐edge technique is proposed to measure the interfacial sharpness in superlattices grown by molecular beam epitaxy. The basis of the technique was to linearly raster the primary Xe + ion beam to form a crater with elongated edges. The SEM images of the crater walls so produced on Al 0.25 Ga 0.75 As/GaAs samples resembled closely the X‐TEM images of the superlattice, thus allowing one to determine the lateral and vertical inhomogeneities in layer stacking. The ion beam was then rastered in a zigzag pattern at lower beam energy, exposing the superlattice layers with better‐resolved interfaces, which gave rise to line profiles as low as 30 Å in apparent depth resolution. This may assure that the technique can compete with X‐TEM, with respect to the superlattice characterization in non‐atomic dimensions.