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Samsung has now taken the initiative and removed the unfortunate brochure. How ...
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Somobody just brought to my attention an interesting document prepared by ...
Samsung tips six predictions in IC scaling
Mark Lapedus
12/6/2010 2:49 PM EST
SAN FRANCISCO - As IC technology enters the sub-20-nm era, chip scaling will become even more difficult and expensive, thereby possibly requiring new materials, structures and processes, according to a technologist from Samsung Electronics Co. Ltd.
During a keynote at the International Electron Device Meeting (IEDM) here, Kinam Kim, president of Samsung Advanced Institute of Technology, said that the cost of IC scaling could force the industry to migrate to 3-D devices, based on through-silicon via (TSV) technology.
Memory technology will scale to the 1x-nm node, but the industry must also look at a new class of products that could replace existing DRAM and NAND, such as MRAM, phase-change and ReRAM, Kim said.
''The current 30-nm node silicon technology is meeting the demand for extremely low power, multifunctional chips that are able to maintain high performance to process and store huge amounts of heterogeneous data,’’ Kim said. ‘’However, there are concerns on whether the current silicon technology can satisfy the technical requirements and overcome the ultimate limits attached to transistors scale down.’’
Here’s some of Kim’s predictions and the associated challenges, which were presented during the keynote:
1. Logic scaling
''At gate lengths less than 20 nm, the use of conventional planar transistors will be nearly impossible because of the extremely thin gate dielectric and junction depths,’’ Kim said.
''Fortunately, silicon technology can be extended thanks to fully depleted (FD) devices such as FD-SOI and multi-gate (MuG) FinFETs. FD device technology is being transferred from R&D to manufacturing. It is expected that the EOT of MuG devices would follow the same trend as the historical SiON EOT trend.
2. TSV-based 3-D parts
Scaling is becoming expensive, causing chip makers to look at TSV-based devices. ''Many groups have reported through-silicon-via based 3D IC (TSV-3D IC) where a single integrated circuit is built by stacking silicon wafers or dies and interconnecting them vertically so that they behave as a single device,’’ Kim said.
''There are many challenging processes such as TSV sidewall etch profiles, poor isolation liners and barrier profiles. These can cause TSV reliability issues due to copper diffusion into the bulk material. In addition to process challenges, there are chip design related issues that need to be resolved in order to maximize the advantage of the TSV-3D IC technology. These issues are: 3D floor-planning (TSV size, the proximity of TSVs to neighboring transistors, and routing with TSVs), thermal management, coefficient of thermal expansion (CTE) mismatch between Cu and Si and mechanical stability,’’ he said.
3. DRAM scaling
Right now, Samsung believes it can scale the DRAM down to at least the 1x-nm node. According to Samsung’s roadmap, the company is currently shipping DRAMs based on 35-nm technology. Samsung plans to ship DRAMs based on 2x-nm technology in 2013 and hopes to devise a 1x-nm part by 2016.
''The most crucial element required for continuing the migration from 30-nm through 20-nm and to ultimately sub-10 nm are: patterning capability of lithography, technological breakthroughs of cell capacitors and transistors from both process and device points of view,’’ Kim said.
''DRAM cell capacitors are most challenging due to its stringent process requirements. The sensed signal should be larger than the noise to guarantee successful sensing. Cell capacitance must be maintained higher than around 20fF per cell, regardless of the technology node,’’ he said.
4. NAND scaling
Like DRAMs, Samsung believes NAND flash will continue to scale at least until the high 1x-nm node.
''NAND flash cell architecture based on the floating gate concept has not changed much since its conception. At each design node, barriers have been overcome by introducing breakthrough process technologies (patterning and dielectric/metal layers) and circuit innovations such as error-correction code (ECC), parallel/shadow programming, wear-level management, data compression schemes, etc.,’’ Kim said.
''However, short-channel-effects (SCE) and decreased number of stored electrons will impede further scaling of planar NAND flash technology at around the 10 nm node,’’ he said.
5. 3-D NAND
Beyond NAND, Micron, Samsung and Toshiba propose to devise 3-D NAND, in which vendors stack parts in a 3-D structure.
''Out of the proposed 3D NAND structures, tera-bit CAT (TCAT) structure is the most promising because it enables the use of a TANOS (CTF with high work function gate and high-k blocking oxide) scheme. Erase speeds can be improved with a high work function gate and tunnel barrier engineering. Retention time can be greatly improved by optimizing blocking layers with combined structures of high-k dielectric oxide,’’ Kim said.
6. Universal memory choices
3-D NAND could be expensive and difficult to make. Other technologies, including so-called universal memories, are in the works. FeRAM, MRAM, phase-change and ReRAM are leading candidates.
''Process issues of 3D NAND have led to consider other numerous schemes for sub-10 nm nodes. According to results of an ITRS poll about the next nonvolatile memories, crossbar type resistive random access memory (ReRAM) ranked top as a strong candidate for the 16 nm and beyond nodes. ReRAM has the advantage of using a simple cross bar structure that can be easily stacked,’’ Kim said.
''PRAM and spin torque transfer (STT) MRAM are other storage class memory candidates. PRAM is now being adopted in mobile phone applications as a code storage memory. The advantage of PRAM is that it can be scaled down to the 15 nm node and beyond. In STT MRAM, much progress on the switching current reduction, circuit, and architecture have been achieved,’’ he said.
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Volatile Memory
12/6/2010 3:44 PM EST
"PRAM is now being adopted in mobile phone applications as a code storage memory." Really? What did Mr. Kim mean exactly? Other than one counterfeit, non-commercial Samsung E2550 with PRAM (now dead and dismantled), there is no evidence that his statement is true (although there are rumors that a few more PRAM-based counterfeit E2550 and even one counterfeit E2558 exist in the wild). The actual commercial Samsung E2550 and E2558 phones use NOR. It appears the technologist from Samsung Electronics Co. Ltd. is attempting to mislead the public.
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daleste
12/6/2010 6:42 PM EST
He said it is "now being adopted." I guess he means that there are plans for future handsets that incorporate the Samsung PRAM.
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iniewski
12/6/2010 7:24 PM EST
I think ReRAM is an interesting candidate for DRAM replacement...getting spin to work it is going to take several years I think...Kris
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goafrit
12/6/2010 8:45 PM EST
These are not new. I have written about this myself in 2007
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no.name_#4
12/6/2010 10:58 PM EST
Didn't EETime publish in 12/2/2010 http://www.eetimes.com/electronics-news/4211190/Phase-change-memory-found-in-handset UBM TechInsights has announced it has found a phase-change memory die inside a multi-chip package inside a mobile handset?
It seems "PRAM is now being adopted in mobile phone applications as a code storage memory." is indeed a true statement.
As a consumer, if I had a PRAM cell phone, my concern would be PRAM's temperature sensitivity, its most notable drawback, .... having a smaller operating window compared to some flash.
I wouldn't want my cell phone memory erased if I should leave behind my phone in a car parked in the hot Phoenix summer sun!!
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Volatile Memory
12/7/2010 10:41 AM EST
no.name_#4: If you actually read the comments section of the article you referenced, you would have realized that the ONLY known handset unit with PRAM in the world is now dead - we don't even know whether it functioned. How can PRAM be adopted "in mobile phone applications," if the only device that "adopted it" has been completely and utterly destroyed? Yes, there are rumors of a few more fake, counterfeit E2550/E2558 handsets with PRAM floating around in Asia, but no one seems to have caught them yet. Therefore, the Samsung statement is false, unless Mr. Kim can show us some "mobile phone applications" that are NOT dead right now.
The temperature sensitivity of PRAM is not the biggest problem in a cell phone (although it is a major concern). The biggest problem is power consumption in write and the write speed. See how careful Mr. Kim qualified the usage "as a code storage memory?" Unfortunately for him, NOR works better than PRAM as a code storage memory, and it is way cheaper, and proven, as evidenced by the fact that the COMMERCIAL, genuine Samsung E2550/E2558 phones actually use NOR memory for code storage.
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resistion
12/7/2010 12:10 AM EST
In the live presentation, he tipped ReRAM as the "universal memory". A little strong, but more surprising after their recent fling with PRAM. Another surprise is their 27 nm NAND is floating gate - what happened to TANOS? Also, they are finally acknowledging the EUV litho as becoming a tad expensive, so are looking at nanoimprint and directed self-assembly.
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Volatile Memory
12/7/2010 12:58 PM EST
resistion: Let's not forget that in 2006 Samsung already knew what the Perfect RAM was:
http://www.samsung.com/global/business/semiconductor/newsView.do?news_id=322
"More scalable than any other memory architecture being researched, [it] features the fast processing speed of RAM for its operating functions combined with the non-volatile features of flash memory for storage, giving it the nickname : perfect RAM."
Samsung, as it turned out in this case, were either quite clueless, or maliciously deceptive.
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iniewski
12/7/2010 1:07 PM EST
To @Volatile Memory: I think it is fairly typical for large companies to hedge bets on various technologies. And you can't really blame them to say something in 2006 and change their mind in 2010...but I do agree that in order to confuse market and competition companies occasionally make claims and announce non-existing or non-proven technologies while at the same time working in dark on something entirely different. There are no brownie points for too much honesty in business ;-)...Kris
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Volatile Memory
12/7/2010 1:41 PM EST
iniewski: In a world of uncertainty, hedging is not only typical, it is the smart thing to do. However, you are welcome to show us just one other example of a large company calling certain non-perfect technology or a device "Perfect." Only then will I concede that Samsung might have been simply hedging rather than being either quite clueless, or maliciously deceptive.
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nineman
12/8/2010 8:08 AM EST
Volatile Memory you really are in a world of your own, trying to whip up criticism out of nothing.
Giving it the nickname 'perfect RAM' is just that: a nickname, tongue in cheek.
You ask "...show us just one other example of a large company calling certain non-perfect technology or a device "Perfect." "
If it helps, I have an original Philips CD player (14-bit) packaged with the legend "Pure, Perfect Sound, Forever". Not true, possibly clueless, not hedging either. Just hype. The Samsung example is very modest in comparison. Happy now?
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Volatile Memory
12/8/2010 10:00 AM EST
nineman: Good find of that 1983 legend! However, the Philips CD player existed and produced sound that many considered Perfect. Where is Samsung's PRAM? It seems the only chip ever used was destroyed by our friends at UBM TechInsights, so we couldn't even determine the extent of its perfectness.
Unless you are in possession of a cell phone with PRAM in it or know where we can buy one?
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ArekZ
12/8/2010 12:55 AM EST
When I read about sub 20/35ns processes I wonder, how the forthcoming high activity of the Sun may affect devices using them ... "Mum, I could not call you because my mobile kept crashing..." 8)
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KB3001
12/8/2010 12:53 PM EST
TSV-based 3-D parts is my pick of the lot.
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goafrit
12/8/2010 1:31 PM EST
We better ask one day if this scaling has any major merit. Do we have to keep the Moore's law?
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iniewski
12/8/2010 2:54 PM EST
To @goafrit...well, Moore's law has allowed silicon industry to become $300B or so business and revolutionized the world in the meantime (PC, cell phone, Internet, etc) so I guess it kind of has worked so far ;-)...how else do we keep providing value and deriving profit while doing it? Kris
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Volatile Memory
12/8/2010 5:39 PM EST
Somobody just brought to my attention an interesting document prepared by Samsung on October 4th, 2010:
http://www.samsung.com/global/business/semiconductor/support/brochures/downloads/memory/MobileMemory_brochure.pdf
Page 3 states: "Samsung’s 512Gb PRAM is combined with Mobile DRAM to deliver performance three times faster than NOR-based MCPs, making it ideal to quickly process large-size multimedia
files."
The "three times faster" is obviously a lie, but hard to prove given that the only PRAM chip in a cell phone has been destroyed.
However, it is obvious that Samsung lied about PRAM being 512Gb. It is just 512Mb. Samsung exaggerated by a factor of 1024x.
And, apparently, nobody has noticed so far. People must be busy installing those chips into fake phones instead of reading marketing materials.
Great job, Samsung!
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Volatile Memory
12/9/2010 3:42 PM EST
Samsung has now taken the initiative and removed the unfortunate brochure. How timely of them!
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