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in total. The metal areas are up to 6 dicing streets create issues where the with metal, the blades’ self-sharpening
microns in thickness and are of varying mechanical saw dicing blades’ diamond mechanism can be defeated, and the
metal types in random locations in each cutting surfaces are fully embedded with blade begins to push into the silicon.
reticle shot field. As metal levels and metallization. High metallization filled Metal interaction then surfaces, and
structures increase in complexity, the dicing streets create dicing issues with can create damage during cutting.
metal density increases. Increasing metal metal loading of the dicing blades that This damage creates yield issues and
density creates more difficulty in loading decrease process capabilities. is compounded during production
mechanical dicing blades, resulting The dicing process typically involves operations. Blade dressing increases, not
in increases chipping, blade wear and a self-sharpening dicing blade that fully solving the problem, and therefore
quality losses. constantly wears and exposes new long term blade breakage and product
The next challenge is process control diamonds. In the case of blade loading damage can result.
in the wafer fabrication process. To
incorporate process controls, the wafer
streets are designed with features to enable
the capability to do live probe, metal
thickness measurements, as well as film
measurements during processing. All these
steps assure that the wafers built meet the
electrical requirements needed, but they
also require additional film, metal boxes
for metrology measurements, as well as test
pads to probe during processing. These are
needed for each metal/fabrication layer that
is placed, and they are stacked in the dicing
street to save silicon for active die and
maximize die per wafer increases.
Figure 3 shows an example of testing
pads’ locations on the die during wafer
fabrication processing. These pads
typically encompass all oxides, as well
as each metal layer, with increasing
thicknesses across the scribe street
during manufacturing as a need for
quality control. As metal layers and
complexity increase, so do the number
of test locations required to monitor
and control wafer fabrication facilities.
The structures are also complicated
with moves to copper back end of line
(BEOL) structures to increase device
performance. Past work has been focused
on optimizing mechanical dicing for use
on aluminum pads and features, but the
move to copper structures has required
significant blade composition changes
and process optimization to level set the
dicing operations.
The last key factor impacting dicing
capabilities is die size interaction as
shown in Figure 4. As die sizes increase,
dicing street loading with metallization
also increases as fab processing typically
requires the same test structures on
smaller versus larger devices. As a result,
this constant component load requirement
loads the entire step field layout with metal
streets. This layout technique, in turn,
causes entire dicing streets to be loaded
with metallization in both the horizontal
and vertical scribe locations. Metal-filled

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