Return on Investment
Some key principles impacting return on Reticle Storage investment
Low Capital Cost: FABs often have 5K active reticles to manage.
Elaborate bare reticle storage tools for that capacity would have capital cost >$20M. It would take a long time to ROI that amount.
It is possible to procure and implement a comprehensive FAB-wide reticle storage and management solution for well under $1M. Low capital
cost will ROI quickly.
Space Efficient Design:
Thousands of reticles are the reality and they must be physically stored somewhere. Logistically,
active reticles should be stored near the litho tools. When storing reticles inside the cleanroom, a space saving design is best.
Itís estimated that 5000 reticles on library shelves will consume about $185K of cleanroom space. Then add $32K annually to sustain
the clean area apportioned to these shelves, and the clearance needed to access them. There is ROI in space saving storage solutions.
FABs are built around photolithography. These tools are a factory's throughput bottleneck by design. Most litho
related delays due to reticles are preventable. Time spent searching for reticles is lost production and therefore lost revenue. When
a "lost" reticle is needed, often an emergency PO is issued to manufacture a replacement quickly. These rush orders are very expensive.
There is ROI in reducing reticle retrieval time.
Photomasks need periodic inspection, cleaning, pellicle work, and
eventual repair or replacement. It does us no good to quickly retrieve a reticle only to find it is flawed and cannot perform its
duty. Reticle maintenance is therefore critical. Every reticle should be tracked in a master database. Any event (usage, history,
inspect, maint) that ties to reticle readiness should be captured and used to predict and schedule required maintenance. There is
ROI in a assuring reticles are suitable for use when called upon.
Reality is that a typical FAB has well over 5,000 reticles inside the cleanroom. They simply must be stored somewhere. Shall we just pile them up on Home Depot supplied shelves? Should we purchase high dollar elaborate bare reticle storage systems with insitu inspect and overhead rail transport? Let's consider the ROI:
ROI - Reticle Storage Systems:
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