Perspectives From the Leading Edge

Before we move on, there were a few more presentations that I wanted to review from the IMAPS GBC (Global Business Council) [see PFTLE “IC Insights Predicts Fast Industry Rebound...,” March 15, 2009; and “Like Swallows Returning to San Juan Capsitrano,” March 20, 2009]. One of the main themes for this meeting was the 3-D infrastructure and how it is going to develop.

Amkor's Bob Lanzone had a nice slide comparing the different classifications of vias (shown below). The two vias-first options (before transistors and before BEOL) are confusing to people, and the industry is looking for a different way to differentiate between them. Bob is going with the term proposed by others in the past year or so — “vias early.” That’s not very descriptive to me, but I do agree that “vias first” should probably be defined only as pre-transistor, polysilicon-filled vias. What does appear to be for sure is that what Bob is calling “vias last” front side, appears to be a last-resort option (as we have discussed previously).

In terms of the infrastructure, in the slide shown below, Bob proposes some options on how the processing steps will be divided among the fab and the OSAT. My opinion is that the ultimate resolution of this will depend on the fab and its capabilities. In general, though, I think everyone is agreed that foundry TSV is the best option from both an economic and infrastructure standpoint.

Our old friend Bob Patti of Tezzaron gave his opinion on the infrastructure as it exists today vs. 2-D infrastructure (shown below). Being one of the leaders in this field, his frustrations with the current infrastructure are obvious from his slide.

Qualcomm, as a user, has certainly been out front pushing on the supply chain to develop. Tom Gregorich gave a very nice presentation on how things were developing from a Qualcomm perspective. The first slide (below) points to why companies are spending time trying to develop 3-D technology. It’s the lure of those solid green bullets that is pushing the field forward even though the current availability is NIL.

When it comes to the processing distribution between the fabs and the OSATS (SATS), Gregorich's next slide (below) looks a lot like Lanzone’s in that they both support TSV in the fabs and question where the thinning, backside processing and bonding will occur. Qualcomm questions this from the standpoint of who will make the necessary investments.

In the next few weeks we’ll be taking a look at:

• The Samsung 3-D roadmap that isn’t.
• Some under-the-radar spin-on glasses that could put the low-k roadmap back on track.

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