Consider, after all, the very reason why STM is trying to get FD-SOI installed at GloFo in the first place. STM has met the same fate that GloFo is trying to avoid - a cash-starved R&D engine that is failing to generate revenues necessary for securing a self-sufficient future.
Hmm after 28nm yes, but currently they have 28nm more ready in their own fab in Crolles. Not sure why they want now GF, too, I guess Crolles is rather a small fab with low volumn and/or they want GF to get some experience with FD-SOI, they'll need them later for 14nm anyways ;-)
Thanks for all the other (here unquoted) insights, really interesting to read.
About the only market segment for forward body biasing I can see are overclockers - no one else is going to want to get anywhere close that portion of the power efficiency curve.
Well check the current CPU-products with >40W TDP. That is basically the market for that. A "bit" broader then mere overclockers ;-) FD-SOI furthermore saves some power due to lower leakage due to the roots in the LP-libraries, thus it should be quite competitive in terms of performance/watt.
Sure about that? Or is that only wishful thinking?
Yes sure, one link of many:
http://www.advancedsubstratenews.co...l-positioned-to-deliver-optimal-finfet-value/
I mean, there might be a reason why STM's presentation materials lay out some information for 14nm and 10nm planar FD-SOI without a single mention of finfet.
Well finfets are IBM's research, STM is not doing it. But it is on the roadmap (3D-FD):
IBM will use SOI-Finfets@14nm for their high-performance process, they mentioned it as successor of their last SHP 22nm PD-SOI process.
Companies can choose, if they are shy of the extra costs of 3D, then they can stick to 2D until 10nm.
And I'm thinking it probably has something to do with the fact that Intel's 22nm materials state that the transistors are fully depleted by virtue of the finfet process. In that case, would there be any advantage to combining it with FD-SOI? I'm not aware of any.
Yes, process costs. The Soiconsortium mentioned 7 Litho and 56 process-steps for Fins@SOI, on bulk these are 9 and 91(!). The Soi wafer is more expensive yes, but the faster Fab-time and better yields are then in total pro SOI - at least according to the SOI people ... probably biased, but I don't think that the basic information about the process steps are wrong.
As well, I was comparing the 28nm FD-SOI that STM is pushing against the 14XM process that GlobalFoundries is promising for next year, or at least their 20nm process that'll supposedly be available this year. Why? Because 'risk production' for 28nm FD-SOI is Q4 of 2013 according to the recent statements... and according to the
14XM FAQ on GlobalFoundries' website they were expecting to deliver 20nm silicon to customers in 2H of 2012 and have customer tape outs of 14XM in 2013. So supposedly their 20nm process will be available before 28nm FD-SOI, and 14XM will be available shortly after...
Well if it is 28nm FD-SOi against 14XM then the latter will probably better, but I wont believe GF's promises on their delivery times. As IDC wrote previously, GF is rushing too much too soon. 28nm was terribly late, according to old promises they were ready with 28nm in the end of 2010(!). Double pattering @20nm and finfets@14nm now doesn't make the process easier. Hopefully, GF will surprise as all and deliver what they promise, but I have my doubts.
Oh? I take it you've seen details on GlobalFoundries' 20nm and 14XM processes then? Or is this simply a guess based only on the general difference between gate first/gate last areas? Because even if that does hold true there's still a pretty marked savings in die size going from 28nm to 20nm.
Only a guess, bc 20nm is gate last for sure. Yes, of course you are correct, the absolut difference is still not that small, but as I said it will be smaller than usual. GF said gate-last will save 10%-20%,a full node shrink saves ~30% (factor 1,41 smaller), thus in the end you roughly gain only 10-20%, theoretical. I guess in practice the metal pitch is very important, too. No clue what numbers we are talking about then, if it is GF@28nm vs. TSMC@20nm.
Yeah, if you assume that shrinking to 20nm and porting from any other 28nm foundry to 28nm FD-SOI are roughly equal in terms of design work, which seems reasonable, then it's just a question of how 20nm bulk compares to 28nm FD-SOI. Sadly I've not found any technical information for TSMC's 20nm bulk floating around from IEDM 2012. But even if it's slightly worse than 28nm FD-SOI the increased cost per wafer will still be more than offset by decreased die size, so it's not exactly a clear decision.
Well yes it's a complicated calculation, first the die-size advantage is important, but we cannot be sure and then you also have to think about yields. These will be worse for 20nm in the beginning, so in the end you might get more good dies out of a 28nm wafer.