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Figure 4: General process flow: edge trimming, bonding, backgrinding, taping, debonding.
after the device wafer has been bonded to
the carrier. Bonding performance can be
inspected by simply looking through the
carrier (optical defect inspection) instead
of sophisticated inspection tools required
with Si carriers.
Flexibility. As the trend in the
industry asks for thinner substrates, we
believe that laser debonding will become
essential moving forward. Having the Figure 5: Cross-sectional view of edge trimming, temporary bonding, and backgrinding.
flexibility now to use a carrier that can thickness) (see Figure 4). The CTE of Wafer stack bonding was performed with
work with current mechanical debonding this glass is well matched with that of Si a SUSS XBS300 temporary bonding
processes, and that aligns with the future in the typical temperature range used for system and two different market-proven,
thinning roadmap, can help companies Si thinning and post-thinning processing. commonly used adhesive systems for
save on development time and cost. In order to conduct a meaningful mechanical debonding (one with device
Below, we describe a demonstration of experiment and mimic real-world release, one with carrier release). Edge
Corning glass carriers working with SUSS semiconductor process conditions, we trimming and grinding details are
MicroTec’s mechanical debonding tool. performed thinning down to a 50µm final discussed in the next section.
General process flow. In order to thickness. The study started with Si edge The subsequent metrology step controls
demonstrate the ability to mechanically trimming prior to wafer/glass bonding the backgrinding process to ensure that
debond glass car riers, Cor ning’s to prevent edge chipping during the the final Si thickness of 50µm is within
SG3.4 glass wafers (200mm diameter, grinding process. A C-type chamfer was the expected tolerance. In addition, the
0.5mm thickness) were bonded to Si used as the edge finish for the glass wafer. uniformity of the adhesive thickness can
wafers (200mm diameter and 0.525mm

Figure 6: Summary of debonding results.

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