Process Technology article @ RWT & TSMC 40nm

Monday 21st January 2008, 01:23:00 PM, written by Arun

Real World Tech just published a great new article on the upcoming process technologies from several companies including Intel, TSMC and Fujitsu. It is based on presentations given at IEDM 2007 in December, and also includes a noteworthy comparison table with processes from days past.

We definitely recommend the read (it's not even that long!) and for those interested in some more data given out at IEDM on TSMC's 45GS (General Purpose Superb) process specifically, we'll point you to this article from Semiconductor International. There's one tiny bit of information in there that is especially noteworthy, and which confirms 45GS is essentially a 40nm node: the gate density is 2.43x 65nm's. This has also been implied by TSMC's management in recent conference calls.

TSMC's official documentation lists 45LP as having 2.05x 65nm's gate density. This also implies that the SRAM cell size on that node is probably nearer to 0.29μm² than 45GS's 0.242μm², although it is not obvious that the shrink in gate density and SRAM cell size has followed the same ratio given the different goals of the two processes.

RWT's article also mentions TSMC claiming 45GS supports SRAM density from 0.202μm² to 0.324μm², presumably depending on the customer's desired area/performance/power trade-off. Interestingly, 0.202μm² is also much nearer 0.41x (1.0/2.43) TSMC's claimed cell size of 0.499μm² on 65nm. This is highly speculative, but we wouldn't be surprised if TSMC was focusing on the 0.242μm² figure because power efficiency (rather than just performance) goes down drastically below that.

Beyond 45GS, TSMC has hinted they intend to create a higher-performance process variant (with presumably similar density) in 2009, perhaps based on high-k and metal gates before deploying it on 32nm. This was discussed very shortly in TSMC's Q2 and Q3 conference calls. However, that process (if it even comes out) would be aimed more at processors (VIA?) than GPUs, and thus it is likely that the next process transition there after 45GS will be 32nm with products coming out in late 2010 and/or early 2011.

Current indicators point at GPUs migrating to the 45GS process node in late Q408 or, more likely, in early 2009. IGPs (on-CPU or not) from all three major players (Intel/AMD/NVIDIA) are also likely to be on 45nm in time for the 2009 Back-to-School OEM cycle.


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process ± 45nm, 40nm, 32nm, intel, tsmc