By Dick James, Senior Technology Analyst, Chipworks

The ConFab 2016 kicked off June 13 in the Encore Hotel in Las Vegas, the 12^th in the series, presented by Solid State Technology (part of Extension Media), which they promote as the “Premier Conference and Networking Event for the Semiconductor Manufacturing & Design Industry.”

The event started with a networking reception Sunday night, giving the early arrivals a chance to mingle with some good food and wine. A feature of The Confab is that networking lunches and receptions are a focused part of the agenda, and time is set aside for face-to-face meetings; these can be pre-arranged by the event staff. Attendance is usually limited to ~150 so that there is ample time for everyone to get together over the three days.

As usual, Pete Singer was the conference chair, and the keynote speaker opening the event was Tom Caulfield, SVP and GM of GLOBALFOUNDRIES’ (GF) Fab 8 in Malta, New York, speaking on “Unlocking the IoT Opportunity for the Next Golden Age.” He surprised me at the start by saying that “the best years of semiconductors are ahead of us, not behind us,” given that it is hard to see even five years ahead at the moment, and pessimists are predicting that leading edge technologies will price themselves out of the business.

Tom then made the point that the main driver for the industry through its existence has been the evolution of connectivity, and the next phase will be as well.

 

And of course that takes us to the Internet of Things (IoT), currently at the peak of the hype curve, but undoubtedly a real phenomenon. McKinsey & Co. have predicted that by 2019/20 the IoT semiconductor value will be $50B – $75B, and they have broken it down nicely into segments and technologies;

What this doesn’t show is that all of the things will generate vast amounts of data, which will need a 5G communications infrastructure, which Tom described as huge, and maybe the biggest opportunity, rather than the silicon in the things themselves.

Then we moved on to the need for collaboration, the business model needs to innovate as well as the technology; though my perception is that there’s a good deal of collaboration in the industry already, though maybe not as much as needed. The GF-Samsung 14 nm agreement was mentioned (though I gather that it is 14 nm only), and design/technology co-optimization, which is now essential in the foundry business – Intel has been doing it for years.

The need for cooperation goes beyond the chip industry, though, and the Albany area was used as an example, since it embodies the three “E”s – education, economy, and ecosystem, i.e. workforce development, government support, and access to the tech cluster around CNSE.

Tom finished up with a plug for the new AMD Radeon 480 GPU, fabbed on the GF 14LPP process (we have one on order!), and a wrap-up of the above.

The theme of the morning session was “The Semiconductor Industry Outlook for 2016 and Beyond”. First up was Dan Armbrust, CEO of Silicon Catalyst, the industry’s first incubator company, which is trying to fill the void of start-up funding for new chip companies. I had not realised it, but the amount of venture capital (VC) money for start-up semiconductor companies has declined to near zero, even though VC funding is itself at almost record levels. Dan and his colleagues have set up a model whereby their partners provide in-kind support, reducing the need for actual seed capital, and Silicon Catalyst will also provide mentoring, physical space, business and legal services, and “lots of pizza”! Contributing partners

include TSMC, Synopsys, Advantest, Keysight, imec, PDF Solutions, Autodesk, Open Silicon, and the
MEMS foundry imt.

The next slide summarizes the model:

So far they have had three screening events, looked at 80+ applications, and selected ten companies for incubation. Seems like a good idea!

Lode Lauwers from imec was the next speaker; he did the usual obligatory description of imec’s capabilities and ecosystem, but once he got into the technical discussion, he put up a roadmap that extended to N+5, i.e. 2 nm, which is the first that I have seen.

In terms of possible technologies, I don’t think there’s anything new, but on our (now failing) two-year process cadence, that takes us out to 2026, so imec is looking a fair way ahead, and it seems the guys in R&D will have jobs for a while.

He also showed the following graphic of where broad applications fit on the roadmaps, so one perception is that IoT will only need technology down to 14 nm – I’m not sure the FDSOI lobby will agree with that, now that some of them are talking about stretching it to 7 nm.

He finished up with some examples of the collaborations that they are doing, using different flows and products such as memory and imagers.

My new colleague Kevin Gibb of TechInsights (TechInsights and Chipworks are now merging) next reviewed recent trends in chips, showing the scaling and some of the process changes we have seen in logic, DRAM and NAND flash technologies, and touching briefly on the die stacking in the Hynix HBM and a ReRAM example.

 

Kevin was followed by Hughes Metras, speaking for Europe’s other semiconductor collaborative research institute, CEA-Leti, with a slightly different roadmap, including FDSOI and their Coolcube monolithic 3D-stacking.

They are also looking at other forms of 3D integration, and Hughes showed examples of 2.5D/3D interposers showed Hughes showed examples of others that also include photonics devices amongst others. Of course we had examples of IoT – CEA-Leti has found applications in everything from medical to truck tires to pipelines.

Mark Reynolds from New York Empire State Development finished the morning session, describing the incentive programs that the state has in place to attract high-tech companies with high-income jobs there.

In essence this boils down to keeping the real estate off the books of the manufacturing company, by providing ready-to-go sites, infrastructure, and workforce, even going as far as building fabs with long term leases at incredibly competitive rates (e.g. $1!), and oftentimes including tooling and equipment. In addition there are tax credits, and the state has pumped oodles of cash into their schools, community colleges and universities to ensure a world class workforce.

We all know this has worked in luring AMD to build what is now the GLOBALFOUNDRIES fab in Malta; more recent examples are the new 300-mm ams fab in Utica (which has just started construction) Solar City in Buffalo (the largest PV plant in the US), the Soraa LED fab in Syracuse, and the GE SiC operation, with the fab in Albany and the packaging operation in Utica.

One could argue that it’s cheaper and easier just to write unemployment or welfare cheques for those in need, but the key to this strategy is the high-income jobs – surveys have shown (I’m told) that one job in a plant such as Malta has a five-to-one multiplier for other jobs, due to the infrastructure and social support (e.g. anything from schools to coffee shops) needed in the local area.

After lunch the main event of the afternoon was a panel on IoT, with Kelvin Low from Samsung Foundry, Rajeev Rajan from GF (VP IoT Product), Uday Tennety of GE Digital, and Jim Hewitt from Siemens as the moderator. There were lots of questions about applications and security, but occasionally we got onto the technology needed for IoT, and how compact the devices could be.

I was curious if the different elements could be integrated into one chip, since the basics of an IoT part are sensor(s), a microcontroller to process the data, a wireless interface, maybe some memory, and power management. These at the least require a range of process technology, since RF processes are usually different from logic and power, never mind the possibly of a MEMS sensor of some sort.

So I put the question, and was mildly surprised that both the foundry guys agreed that it is becoming possible, since FDSOI, with its back bias capability, allows a wider range of voltages and frequencies, and they clearly see this as an opportunity for them to get seriously into the IoT chip market.

The panel lasted an hour and a half or so, then we had a break before another reception.

By Dick James, Senior Technology Analyst, Chipworks

It’s spring in the north-eastern part of North America, and that means it’s the time of year for the Advanced Semiconductor Manufacturing Conference, in the amiable ambiance of Saratoga Springs, New York. The conference took place a couple of weeks ago, on May 16 – 19.

As the name says, ASMC is an annual conference focused on the manufacturing of semiconductor devices; in this it differs from other conferences, since the emphasis is on what goes on in the wafer fab, not the R&D labs, and the papers are not research papers – some are better described as “tales from the fab”! After all, it’s the nitty-gritty of manufacturing in the fab that gets the chips out of the door, and this meeting discusses the work that pushes the yield and volumes up and keeps them there.

I always come away impressed by the quality of the engineering involved; not being a fab person myself any more, it’s easy to get disconnected from the density of effort required to equip a fab, keep it running and bring new products/processes into production. Usually the guys in the fab only get publicity if something goes wrong!

There were 96 papers spread over the three days, 60 presentations and 36 posters, and the highest attendance ever at 350+ (registration was actually closed on day 1 – we ran out of room!). In addition we had keynotes from Don O’Toole of IBM and Christine Furstoss of GE Global Research, a tutorial on Nanoscale III-V CMOS by Jesús del Alamo from MIT, and to finish the Wednesday afternoon there was a panel discussion on “Moore’s Law Wall vs. Moore’s Wallet, and Where Do We Grow From Here?”. Bob Maire of Semiconductor Advisors wrapped up the conference Thursday lunchtime with a talk on China’s effect on the semiconductor biz; “Mergers & Acquisitions in the Semiconductor Industry – Could China Cause Continued Consolidation?”

I guess it’s a reflection of the location, but 46 out of the 96 papers were from Silicon on the Hudson – GLOBALFOUNDRIES, IBM, and CNSE/G450 affiliates. Having said that, there were papers from the likes of Samsung, TSMC, and UMC, not to mention NXP, Infineon, ON Semi, and others, plus some academic and student papers. It’s always tough to get papers from far afield these days, especially with tightening travel budgets and visa requirements, not to mention the gut desire to keep internal information in-house.

And of course Chipworks usually has an offering, though we missed out last year due to personal circumstances, otherwise it would be twelve years in a row. It’s a bit of an odd fit, since we are a service company that doesn’t make anything; but we do take the leading edge chips apart, and it seems the fab guys at the conference like seeing the competition’s stuff – and their own – since, if you’re deep into running the fab, you don’t get much of a chance to look at the final product.

And, now that we’ve been presenting since 2005, our papers are actually a condensed history of the technology from the 90-nm era down to 14-nm finFETs – if you read the references at the end of the blog you’ll see we’ve covered a fair spread of technology, not just logic transistors, but also flash and DRAM memory.

The initial reason for my submitting a paper back in 2004 for the 2005 conference was that ASMC that year was co-located with Semicon Europa – and I liked the idea of a trip to Munich! We were also a growing company, and starting to flex some of our marketing muscles by presenting at, rather than just attending conferences. In that context, the 2005 conference was a success, since Tom Cheyney, editor of the now-defunct Micro magazine, invited me to write regular articles for the publication, and that led to a series of articles and blogs that is still going.

Looking back at the older presentations, they really are a trip down memory lane – remember that first Intel 90-nm transistor with embedded silicon-germanium source/drains for the PMOS? We looked at that in 2005 [1].

 

The compressive stress given by the SiGe turned out to be a very effective tool for cranking up the strain in the channel, to the extent that PMOS and NMOS drive currents are now comparable, definitely a different design paradigm from the days of my youth.

And it turned out that the technology was transferable to high-k, metal-gate (HKMG) finFETs – witness the latest 14-nm Intel PMOS device:

 

Taking a different tack, IBM was already using SOI, but before they used embedded stress techniques, the SOI layer was only 45 nm thick – not quite FDSOI, but thinner than their current (GLOBALFOUNDRIES) HKMG offering that uses 80-nm thick SOI.

 

As you can see below, things are considerably more complex these days!

 

When it comes to memory, 90-nm DRAM was the order of the day, and the recessed channel array transistor (RCAT) had just been introduced:

 

 

Now we have 10-nm class (likely 18-nm) 8-Gb DRAMs, though the latest I reviewed at ASMC [9] was a 26-nm 4-Gb part in 2013 – that was three generations ago!

 

 

In the meantime we have seen the introduction of buried tungsten saddle-fin transistors for the wordlines (buried wordlines – BWL), ZAZ (zirconia/alumina/zirconia) high-k capacitor dielectrics, and air-gaps; shrinking cell area by more than a factor of ten. The node definition has also moved from half the M1 pitch to half of the active silicon pitch, nothing stays the same in our business.

I didn’t talk about flash that first year, but a couple of years later [3] the leading edge was a 62-nm, 8-Gb part, and 50-nm was starting to come into production. The conference that year was in Stresa, on Lake Maggiore in Italy, one of the more exotic locations that we’ve been to.

 

The latest in planar flash in 2013 [9] was a 19-nm Toshiba 128-Gb device:

 

We still have the conventional floating gate/control gate structure, but cell size has shrunk by an order of magnitude, we have air gaps between cells, and in order to keep effective coupling between control gate and floating gate, the aspect ratio of the floating gate has increased from ~1.3 to ~4.8.

In 2016, of course, we have planar flash down to the 15-nm generation, including the use of high-k dielectric, and we are into the third-generation vertical flash parts.

So much for then and now – this year’s conference had 15 different sessions:

• Contamination Free Manufacturing (CFM)
• Advanced Metrology I & II
• Defect Inspection I & II
• Factory Optimization I & II
• Advanced Equipment and Materials Processes
• Yield Enhancement & Yield Learning
• Advanced Equipment/CFM
• Advanced Patterning/CFM
• Advanced Process Control (APC)
• Yield Enhancement
• 3D TSV

Including a poster session for shorter papers that covered all the above topics.
The subjects of individual papers ranged from improvements to chemical-mechanical planarization, through threshold voltage variations in HKMG gates due to non-uniform alloying, to ‘smart manufacturing’ in legacy 200mm fabs, and multiple papers on virtual metrology – i.e. a broad swath of the practical wafer manufacturing problems to fab loading algorithms and everything in between. The detailed schedule can be found here, and no doubt the proceedings will be available through IEEE Xplore in due course.

Next year’s ASMC will again be in Saratoga Springs, on May 15 – 18; we hope to see you there!

References

• James, 2004 – The Year of 90-nm: A Review of 90 nm Devices, Proc. ASMC 2005
• James, Low-K and Interconnect Stacks – a Status Report, Proc. ASMC 2006
• James, Nano-Scale Flash in the Mid-Decade, Proc. ASMC 2007
• James, From Strain to High K/Metal Gate – the 65/45 nm Transition, Proc. ASMC 2008
• James, Design-for-Manufacturing Features in Nanometer Processes – A Reverse Engineering Perspective, Proc. ASMC 2009
• James, Recent Innovations in DRAM Manufacturing, Proc. ASMC 2010
• Fontaine, Recent Innovations in CMOS Image Sensors, Proc. ASMC 2011
• James, High-k/Metal Gates in Leading Edge Silicon Devices, Proc. ASMC 2012
• James, Recent Advances in Memory Technology, Proc. ASMC 2013
• James, 3D ICs in the Real World, Proc. ASMC 2014
• James, High-k/Metal Gates in the 2010s, Proc. ASMC 2014
• James, Moore’s Law Continues into the 1x-nm Era, Proc. ASMC 2016