Several high technology applications, such as the
development of Integrated Circuits, require complex layer-by-layer
integration of new materials and processing over large areas that
rely on techniques such as chemical mechanical planarization (CMP)
to remove material in a planar and uniform fashion CMP is an
example of a process controlled by various parameters such as
slurry concentration, spin speed, pattern density, hardness of the
polishing pad, temperature etc where minor deviation from the set
process parameters leads to several critical defects including
stress cracking, delaminating at weak interfaces, pitting and
corrosive attacks from slurry chemicals The current method of
detection of these defects is scanning electron microscopy (SEM),
which on a 12inch Si wafer can take up to 48 hours Likewise, there
are many other large area polymeric coating applications such as
pacemakers where pin-hole defects can be critical to performance
The detection of these defects poses a major challenge and is an
example of the classic “needle-in-haystack” problem for nano and
macroscale detection We address this issue by developing a novel,
efficient method for the optical detection of surface topographical
features using fluorescent nanoprobes, which are surface-modified
polystyrene nanospheres whose ability to detect surface features
can be tuned via size (entropic effects) and chemical properties
(enthalpic effects) We have successfully applied this approach to
detect numerous types of artificial and natural defects on
polymeric and non-polymeric substrates including lines, pinholes
and sharp edges This method can elucidate the surface structure of
large areas in a minimal amount of time It is estimated that this
new method will decrease imaging time compared to traditional
imaging methods like atomic force microscopy (AFM) and SEM by 50
fold Our defect detection approach is particularly applicable to
many problems where polymers are used in the form of surface and
interfacial layers in hybrid nanomaterial films

http://absimage.aps.org/image/MAR12/MWS_MAR12-2011-008019.pdf

High Fidelity Detection of Defects in Polymer Films using Surface-Modified Nanoparticles

Causes of high-ohmic contact resistance were explored by analyzing several integrated circuit samples with an ion microprobe. Presence of oxide and dopant depletion at the interface were indicated. Mapping of oxygen vs depth through an oxide revealed that not only the elements present, but also the layered structure of the material could be observed. The possible production of artifacts due to electrostatic charges on the surfaces of a sample was noted.

J. W. Dzimianski

Papers

Use of an Ion Microprobe in Semiconductor Failure Analysis