K. Green, W. Beard, X. Zhang and R. Armstrong
X-ray diffraction topography is the name given to several x-ray diffraction
techniques where large area x-ray beams diffracted from a crystal proved
detailed information about the surface structure and internal perfection
of crystal microstructures. Since x-ray topographic techniques are
based on Bragg (reflection) or Laue (transmission) diffraction from a crystal
lattice, they are extremely sensitive to any atomic lattice imperfections
and strains. Alterations of the interplanar spacing as small as one
part in ten thousand extending over a reasonable number of atomic cell
lengths can be recorded as a corresponding change in the diffracted beam
intensity. Line Modified-Asymmetric promise in the field of microelectronics.
The LM-ACT system is designed with low angular divergence in the x-ray
beam probe. Low prove beam divergence allows details of device geometries
on the order of microns to be resolved in the recorded x-ray intensity
variation if the diffracted beam. The LM-ACT system was applied here
to the study of integrated circuits (IC) after specific processing steps
were accomplished during IC fabrication and in the final product
condition.
Topographs obtained from specular crystal surfaces that were implanted
and non-implanted regions; details of the mask patterns have been resolved
on the order of a few microns. LM-ACT topographs from annealed, and
unannealed, implanted specimens showed marked differences and as a result
it is suggested that LM-ACT would be beneficial in optimizing the processing
schedule for a particular wafer/electronic system. A significant
feature the LM-ACT technique is the capability of producing high-resolution
stereo-pair topographs that provide quantitative information through the
depth of individual process layers in an integrated circuit.
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