Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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Hearing the news that GlobalFoundries would be offering two flavors of FD-SOI, ASN asked the company to explain the strategy further. Here are the responses provided by Subi Kengeri, Vice President of Advanced Technology Architecture.

Subi Kengeri, VP Advanced Technology Architecture, GlobalFoundries

What do you see as the FD-SOI benefits for chip designers?

• Lower SRAM Vmin for retention and lower operating Vmin for Logic
• Wider range of Voltage operation for performance/power trade-off
• Total dielectric isolation equates to lower capacitances, lower leakage, and latch-up immunity
• Ultra-thin silicon film provides excellent electrostatic control and optimum transistor performance
• Back-bias control gives an additional speed boost
• Simple planar process using same front end and back end as our 28SLP process, which means fewer process steps and fewer masks, helping to absorb the additional substrate cost

What are your plans for making FD-SOI available to your customers?

We are the manufacturing partner for ST’s FD-SOI technology. We also are planning to offer the technology to other customers who may be interested, but we have not announced details yet. We are the only pure-play foundry with deep experience in both bulk and SOI technologies, which allows us to offer a broader range of technologies at advanced nodes.

GlobalFoundries’ Fab 8 in upstate NY

Can you elaborate on the “maximum” version of FD-SOI — tuned for specific applications — what sorts of things would those be?

Examples of features in the Maximum version of FD-SOI:
a. Back-bias capability on logic for higher performance
b. Denser SRAM by taking advantage of lesser variability of Fully depleted device
c. Base Vts tuned for specific applications (performance vs power trade-off)

And the “minimum” version — a simple and “out of the box” FD-SOI technology — who/what is this for?

a. No Back-bias supported
b. All SRAMs are foot-print compatible to 28SLP
c. Fully depleted device offers better Vmin and power advantages: Optimized for Mobile Applications

Are there any special logistics in terms of the PDK, IP, etc?

a. PDKs are similar to bulk CMOS, except the models will support a 4-terminal device for Back-bias
b. In the base version (termed as minimum version above), IP’s Physicals are fully compatible with bulk CMOS, but would require electrical re-characterization to take advantage of improved FD-SOI device characteristics
c. In the extended version (termed maximum version above), IPs will be designed to take advantage of Back-bias for better performance/power trade-offs in specific applications

What is the next node, and when will that roll out?

See slide 8 of [this] presentation:

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Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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The 2013 Common Platform Technology Forum showcased “the latest technological advances being delivered to the world’s leading electronics companies,” so of course SOI-based topics were well-represented. Happily, those of us who weren’t able to get over to Silicon Valley were able to attend “virtually” via a live stream (which is now reposted – click here to register and watch it yourself).

The Common Platform Alliance is IBM, Samsung and GlobalFoundries, operating, as IBM’s Dr. Gary Patton points out, as a “virtual IDM”.

Here’s a round-up of the SOI-based highlights.

DR. GARY PATTON, VICE PRESIDENT OF SEMICONDUCTOR RESEARCH & DEVELOPMENT CENTER, IBM

In his keynote address, Gary covered the following SOI-based innovations:

Flexible computing with FD-SOI. (Courtesy: IBM, Common Platform Technology Forum 2013)

• FinFETs: As ASN readers know, IBM is driving FinFETs very hard. With ARM & Cadence, they taped out their first 14nm FinFET processor last fall (on SOI). Gary’s talk gave an overview of the evolution of device structures, including PD-SOI (the basis for IBM’s Watson supercomputer), FD-SOI, FinFETs and future structures and materials.

• Wearable electronics & folding displays – IBM has developed a new, low-cost technique that starts with the FD-SOI technology developed with ST and Leti, for manufacturing silicon-based electronics on a flexible, plastic substrate. Gary showed a sample, and said that “research suggests that flexible, affordable electronics can be made with conventional processes at room temperature.”

• Silicon nanophotonics – most all of the industry’s nanophotonics work is on SOI, and IBM is no exception here.  As Gary notes, “…the key innovation isn’t just the technology…it’s the fact that it’s commercial and scalable…”.
• Carbon nanotubes breakthrough – IBM has attained 10,000 working nanotube transistors on a single device using standard semiconductor processes.  As we noted in ASN when this news broke last fall, IBM researchers fabricated trenches made of hafnium oxide onto SOI wafers, which allows the self-assembly by the carbon nanotubes into neat rows rather than a spaghetti-like tangle.

As seen here, carbon nanotubes start on an SOI wafer. (Courtesy:IBM, Common Platform Technology Platform 2013)

MIKE NOONEN, EXECUTIVE VP, GLOBAL SALES, MARKETING, QUALITY & DESIGN, GLOBALFOUNDRIES.

In Mike’s keynote on particularly innovative customers, he covered ST’s FD-SOI technology.  Here are the main points he made about it:

• STMicroelectronics has been a partner in the Common Platform.
• FD-SOI leverages 80% FEOL of the 28nm SLP; the BEOL is identical to 28nm LP.
• “You can really dial-in optimal transistor performance,” he said.  The thin silicon channel introduces “interesting and exciting capabilities”, including:
  - lower leakage, lower capacitance, enhanced latch-up immunity, electrostatic control;
  - speed boost through back biasing;
• This technology is a simpler planar process:
  - reduced masks offsets cost;
  - considerable IP reuse.
• With a nod to Soitec, the world-leader in SOI wafers, he said, “Soitec has been a really enthusiastic evangelist of this technology, and I really want to acknowledge their efforts in making Fully-Depleted over SOI something that the industry has become very excited about.”  He added that they’re joined by MEMC and SEH as SOI substrate suppliers.
• Regarding the roll-out, he concluded, “A PDK of this technology is available this quarter, and GlobalFoundries has partnered with ST for volume manufacturing and will be entering risk production in the 4th quarter of 2013, with volume production in the first half of 2014.”

GlobalFoundries’ keynote highlights FD-SOI. (Courtesy: GlobalFoundries, STMicroelectronics, Common Platform Technology Forum 2013)

HANDEL JONES, OWNER & CEO, INTERNATIONAL BUSINESS STRATEGIES

In a “fireside chat” with Brian Fuller, Silicon Valley Bureau Chief, EETimes, Handel Jones touched on a number of SOI-related topics.  (In case you missed it, Handel recently wrote an excellent article for ASN on FD-SOI vs. Bulk & FinFET economics.) In addition to his general discourse on the impact of design & process issues on cost/gate, the importance of the ecosystem, and general industry outlook, here are some of Handel’s SOI-related observations during the forum chat:

• RF: he is particularly impressed with IBM’s work on RF, which he says is “…doing extremely well.”  As you may have seen previously in ASN, IBM’s CMOS 7RF SOI technology, which the company says offers significant cost advantages to designers of mobile handsets, has been on SOI for over five years.
• FD-SOI: When asked about any single, major disruption on the horizon, he noted that designing with FinFETs for mixed signal is tough, so there may be a delay there.  However, FD-SOI looks very positive, he says. He sees FD-SOI offering lower power, lower cost/gate, re-usable IP and scalability to 14nm.

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Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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What a great start to 2013: at CES in Las Vegas, ST-Ericsson announced the NovaThor™ L8580 ModAp, “the world’s fastest and lowest-power integrated LTE smartphone platform.” This is the one that’s on STMicroelectronics’ 28nm FD-SOI, with sampling set for Q1 2013.

And it’s a game changer – for users, for designers, for foundries, and for bean counters.  Here’s why.

The NovaThor L8580 integrates an eQuad 2.5GHz processor based on the ARM Cortex-A9, an Imagination PowerVR™ SGX544 GPU running at 600Mhz and an advanced multimode LTE modem on a single 28nm FD-SOI die.

ST-Ericsson’s NovaThor(TM) L8580 on ST’s 28nm FD-SOI features a 2.5Ghz eQuad(TM) app processor with ultra-low power consumption. (Courtesy: ST-Ericsson)

In the eQuad CPU architecture, each processor core can operate as a high-performance core or a very-low-power core, depending on what’s needed at the moment. Since all the eQuad cores can adapt to the needs of the user at any given time, there’s no need for the dedicated low-power cores found in other multi-core CPU architectures. Remember, the 2.5GHz cores in the L8580 are the mobile industry’s fastest, or conversely, at 0.6V in low-power mode, the industry’s most battery-friendly. With all 2.5GHz cores working together, expect blazing high-performance when you’re doing something like browsing the web. But when phone’s your pocket, those cores will take barely a sip of power.

The NovaThor L8580 is essentially a straight port from 28nm bulk to 28nm FD-SOI of the (very successful) NovaThor L8540, with just a bit of tweaking to fully leverage cool things you can do with FD-SOI, like biasing to increase performance and conserve power.

For the folks designing smartphones and tablets (and ultimately for the end-user), that port to FD-SOI gets the NovaThor L8580:

• CPUs running 35% faster and GPU and multimedia accelerators running 20% faster. In terms of multimedia performance, they’re supporting 1080p video encoding and playback at up to 60 frames per second, 1080p 3D camcorder functionality, displays up to WUXGA (1920×1200) at 60 frames per second and cameras up to 20 megapixels. (Hence their use of the descriptive “extraordinary”.)
• 25% less power consumption than rival architectures when running at high-performance  levels – think Cooler Operation.
• A low-power mode can deliver up to 5000 DMIPS at 0.6V – more than enough computing power for the majority of applications in everyday use. A key point here is that it enables stable SRAM operation at 0.6V – have you heard of anyone matching this? The result is that this low-power mode consumes 50% less power to deliver the same performance compared with alternative solutions in bulk CMOS.

It all adds up to big battery savings – this is the extra day CEO Didier Lamouche promised us in Barcelona last year when they announced this chip.

ST-Ericsson has posted an amazing video, filmed live at CES 13. In the first part of the demo (re: high-perf), on a Samsung Galaxy S3, they’ve got the Sky Castle 3D Graphics Demo launching twice as fast on FD-SOI as the bulk equivalent, and hitting 2.8GHz! And in the second demo (re: low power), they’re hitting 1GHz using just 0.636V, which would take 1.1V on bulk.

Design Highlights

For the ST-E designers, most of the IP blocks were directly re-used from the bulk design, so the porting to FD-SOI was extremely simple and fast.

For the manufacturing folks over at STMicroelectronics (and starting this year, at GloFo), FD-SOI is a planar technology that re-uses 90% of the process steps used in 28nm bulk. The overall manufacturing process in FD-SOI is 12% less complex, so they’ve got lower cycle time and reduced manufacturing costs (bean counters take note, please). They also point out that the manufacturing tools for FD-SOI are much simpler than those required for FinFETs.

Wondering what’s next? The 14nm FD-SOI node is already in development, the ARM Cortex-A15‘s  on the radar, and the FD-SOI roadmap is already defined up the 10nm node.

With FD-SOI, you can do much more with body-biasing (aka back-biasing) than you can in bulk (which suffers from too much leakage). Thanks to the ultra-thin insulator layer in FD-SOI, the biasing creates a buried gate below the channel, so it effectively acts like a vertical double gate transistor. This facilitates the flow of electrons, leading to a higher voltage in the body, and faster switching of the transistor. (Image courtesy ST-Ericsson)

With FD-SOI, you can hit higher speeds with lower operating voltages. This is because the buried oxide layer prevents electrons from leaking away as they travel through the channel from the source to the drain (this sort of leakage is a major source of power consumption in 28nm bulk, which depends on doping to handle leakage). Interestingly, this graph shows ST-E going down to 0.5V – which is incredibly impressive. (Image courtesy of ST-Ericsson)

(Image courtesy ST-Ericsson)

(Image courtesy ST-Ericsson)

As the (now award-winning) folks over at ST and Leti described for us a few years ago, designing a good SOC involves using the right blend of low, standard and high-Vt devices according to the target application and how it’s being used at any given time.  The ST-E designers use this feature to apply different voltages independently to the top and the buried gates of the FD-SOI transistor, which effectively changes its characteristics. By choosing optimal combinations of the voltages, the transistor characteristics can be transformed from those of a very high-performance transistor to those of a very low-power transistor. A processing core built up of such transistors can operate as if it were in fact two cores – one optimized for high performance and the other for low power. (You can’t do this with FinFETs, btw.)

Just Posted: FD-SOI video & white paper

Just as this blog was going online, ST-Ericsson posted an excellent, in-depth white paper; and in partnership with STMicroelectroics, a YouTube video detailing the how’s and why’s of FD-SOI.Here are the links — you really don’t want to miss these:

• Multiprocessing in Mobile Platforms: the Marketing and the Reality
In this white paper, ST-Ericsson’s Marco Cornero and Andreas Anyuru “…illustrate and compare the main technological options available in multiprocessing for mobile platforms, highlighting the synergies between multiprocessing and the disruptive FD-SOI silicon technology used in the upcoming ST-Ericsson products.”

• An Introduction to FD-SOI

STMicroelectronics and ST-Ericsson have teamed up on this excellent video, which garnered 1250 views within the first four days of its posting on YouTube. The animations and comparisons highlight why FD-SOI is so fast, and so cool.

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Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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What would a port to 28nm FD-SOI do for your design?  A recent announcement by CMP, STMicroelectronics and Soitec invites you to find out.  Specifically, ST’s CMOS 28nm Fully Depleted Silicon-On-Insulator (FD-SOI) process – which uses innovative silicon substrates from Soitec and incorporates robust, compact models from Leti – is now available for prototyping to universities, research labs and design companies through the silicon brokerage services provided by CMP (Circuits Multi Projets®). ST is releasing this process technology to third parties as it nears completion of its first commercial FD-SOI wafers.  What you can get from CMP is the same process technology that will be available to all at GlobalFoundries in high-volume next year.

The CMP multi-project wafer service allows organizations to obtain small quantities of advanced ICs – typically from a few dozen (for a prototype, say) to over a hundred thousand units (for low-volume production). CMP is a non-profit, non-sponsored organization created in 1981, with a long history of offering SOI and other advanced processes. It offers industrial quality process lines – with industrial-level, stable yields. Headquartered in Grenoble, France, CMP has over 1000 clients in 70 countries.

The cost of ST’s 28nm FD-SOI CMOS process at CMP has been fixed at 18,000 €/mm², with a minimum of 1mm².  At this point in scaling, that gets you about two million gates – about eight million transistors.  So the pricing is very aggressive for an advanced technology node – and it comes down if you get more than 3mm², and even more if you get >15mm², Kholdoun Torki, CMP Technical Director explained to ASN.

Dr. Torki was kind enough to elaborate a bit on the particulars for us. Here’s what he says. The ST design kit contains a full-custom part, and standard-cells and I/O libraries with digital design-flows supported under Cadence Encounter and Synopsys Physical Compiler. The design-kit is from ST Front-End Manufacturing and Technology, Crolles. CMP delivers this design-kit under NDA.

Devices are supported for UTSOI (ultra-thin SOI) models, which were developed by and are the property of Leti.

The UTSOI model is available under Eldo from Mentor and Hspice from Synopsys. It is also expected to be available for Spectre (Cadence) and for Golden Gate and ADS (Agilent) within the next few months.

CMP provides the first level support (installation, and general questions on the use of the kit). Multi-Projects Wafer runs are organized at ST Crolles. For low volume production, a quote is issued on a case-by-case basis, on request.

The ST 28nm FD-SOI offering has a true 28nm BEOL metallization with .1µ metal pitch, says Dr. Torki.

CMP also has offered the Leti 20nm FD-SOI R&D process since 2010. (In fact for those looking even further ahead, Leti has predictive model cards down to 11nm.) It is expected the 20nm FD-SOI process from ST, incorporating strategic technology from Leti, will be available from CMP towards the end of next year, although the exact date has not yet been fixed.

How it works

In Multi-Project Wafer runs, costs are shared (and reduced) because the reticle area is shared across customers. CMP offers one-stop shopping, including:

• NDA processing
• the design-kits linking CAD and processes, and related support
• Design submission, checking, and final database to the Fab
• Wafer sawing and Packaging
• Export license processing
• Chip delivery

Because reticles are shared across multiple designs, CMP customers benefit from very attractive pricing. (Courtesy: CMP)

Last year (2011), CMP handled 273 circuits, including prototypes, low-volume production runs and industrial applications.

For organizations like the 77 customers in 23 countries using 28nm bulk CMOS through CMP’s program, migrating from 28nm CMOS bulk to 28nm FD-SOI will be seamless, says Dr. Torki. There are no disruptions in process or design. There are the same layer numbers and names, so they can load a bulk design directly into an FD-SOI design environment. They use the common design-rules platform (ISDA alliance design-rules), and bulk devices can be co-integrated with FD-SOI devices as needed.

These are real, leading edge chips and circuits we’re talking about. Here’s what you get:

• 28nm HK/MG FD-SOI with ultra-thin BOX and ground plane
• 10 Cu metal layers: (6 thin + 2 medium + 2 thick)
• Triple Well (Deep N-Well allows the P-Well to be isolated from the substrate)
• Single IO oxide + Single core oxide.
• Double VT: 1.0V Low Vt transistors (LVT) + 1.0V super Regular Vt transistors (RVT)
• Low Leakage (high density) SRAM using LP core oxide
• IO supply voltage: 1.8 V using the IO oxide.
• Ultra Low k inter-level dielectric
• 0.10µ metal pitch
• Self-aligned silicided drain, source and gate
• Poly and active resistors: Silicide protection over active areas for ESD protection
• CMP for enhanced planarization (on STI, Contacts, Metals and vias).

FD-SOI Transistor (Courtesy: ST)

The 28nm FD-SOI standard-cells, IO cells and related IP are all from ST. The CORE cells Libraries include:

• CORE_LL: Low Power LVT
• CORE_LR: Low Power RVT
• CLOCK (LL and LR): Buffer cells and the same for clock tree synthesis
• PR: Place and route filler cells.

The IO cells Libraries include:

• Digital
• Analog
• Flip-Chip bumps
• ESD

You can find more details at the CMP website, or from the paper Dr. Torki presented at the 2012 SOI Conference.

So this represents a real opportunity.  Universities, often doing important research for industrial partners, have long known the value of using services like CMP’s. But with this latest ST-CMP-Soitec announcement, the fabless world can do more than kick the tires – they can take 28nm FD-SOI for a real test drive.

FD-SOI promises an extremely cost-effective, performance-enhanced, power-miser of a chip.  Wouldn’t you like to give it a try?

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Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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It’s a bright green light from the world leaders in SOI wafer capacity. Soitec, the world leader in SOI wafer production, and long-time partner Shin-Etsu Handatai (SEH), the world’s biggest producer of silicon wafers, have extended their licensing agreement and expanded their technology cooperation.

SEH is a $12.7 billion company, supplying over 20% of the world’s bulk silicon wafers. SEH’s relationship with Soitec goes way back: they were one of the original corporate investors back in 1997, and the first to license Soitec’s Smart CutTM technology for manufacturing SOI wafers.

With its 300mm SOI wafer production fabs in France and Singapore, Soitec has an expandable installed industrial base of two million wafers per year.

As Horacio Mendez, Executive Direct of the SOI Consortium told ASN, “This is a very significant announcement. The substrate supply chain is fully engaged: we have multiple independent suppliers that can clearly meet the market demands for all key sectors, including mobile devices. As the advanced technology nodes ramp, the wafer production is in place; and very importantly, the capacity is expandable to provide maximum flexibility to customers.”

SEH has been manufacturing standard SOI wafers using Smart Cut technology for years. And last year, the company said it had completed development of its ultra-thin BOX (aka UTB — the wafers used for planar FD-SOI) substrates. Nobuo Katsuoka, director of the SOI program at SEH, recently told Semiconductor Manufacturing & Design, “SEH is delighted to deliver the products on request.”

Wafers for FD-SOI (a “planar” “2D” technology) have Angstrom-level uniformity in their ultra-thin layers – so it’s excellent news that the the industry’s two leaders are both supply sources.

SOI wafers for FinFETs (a “vertical” or “3D” technology, for which the top silicon and insulating BOX layer don’t have to be ultra-ultra-thin) have also long been available from Soitec, SEH and other sources.

With respect to this announcement, SEH’s Katsuoka said, “We are very excited about the business opportunities for SOI products, and we look forward to working with Soitec to extend the global supply chain for new products, such as FD-SOI and SOI for FinFETs, which are showing potential benefits in mobile and embedded applications. Our relationship with Soitec has been a very positive and fruitful one, and we are excited to extend that collaboration. The unique features of Smart Cut will enable our two companies to jointly improve global output for existing and new SOI products.”

As Steve Longoria, SVP of WW Business Development at Soitec, told ASN, “The wafer is the front end of the manufacturing process. This announcement is a proof point of new energy for robust, multi-source supply for impending high-volume demand.”

BEYOND LOGIC

The newly announced Soitec-SEH agreement also extends the companies’ commitment to wafers for a broad-range of areas. For example, there are major market opportunities in SOI for RF devices, power, MEMS/sensors, photonics and more.

The agreement also extends to R&D for technologies of the next wave. We might think of Smart Cut as an SOI technology, but in fact it’s really a manufacturing technology that can be applied to a huge range of wafer materials. As a result of the extended agreement, SEH will continue to use Soitec’s industry-defining Smart Cut technology to manufacture SOI wafers.  What’s more, SEH will now also be able to extend its Smart Cut manufacturing capabilities to other materials, a trend commonly referred to as Silicon on Anything or SOA (any material on top of which there is a thin film of plain silicon), which will allow SEH to further expand its scope of applications.

So with an abundance of opportunities, a robust multi-source supply chain for the front end of the chip manufacturing process, top-quality wafers that enable savings and efficiencies – in short, better end-user value – it’s all systems go for high-volume demand.

This illustration shows how Smart Cut, Soitec’s proprietary engineered wafer technology, works. The industry standard, this revolutionary wafer bonding and layer splitting processes makes it possible to transfer a thin layer of material from a donor substrate to another substrate, overcoming physical limitations and changing the face of the substrate industry. The Smart Cut technology was originally developed by the CEA-Leti. Soitec holds exclusive exploitation of CEA-Leti rights into the Smart Cut technology, including the right to sublicense to SEH. The technology was made viable for SOI high-volume commercial production by Soitec, and is now protected by more than 3,000 patents owned or controlled by Soitec.

Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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In the spring of 2012, STMicroelectronics announced the company would be manufacturing ST-Ericsson’s next-generation (and very successful) NovaThor ARM-based smartphone/tablet processors using 28nm FD-SOI process technology. With first samples coming out this fall, ASN talks to Jean-Marc Chery, Executive Vice President, General Manager Digital Sector, Chief Technology & Manufacturing Officer, STMicroelectronics about the manufacturing process and the expected results.

Jean-Marc Chery, Executive Vice President, General Manager Digital Sector, Chief Technology & Manufacturing Officer, STMicroelectronics (Photo credit: Artechnic)

Advanced Substrate News (ASN): You taped out ST-Ericsson’s 28nm FD-SOI NovaThor in the beginning of September. Did that go as you expected?

Jean-Marc Chery, STMicroelectronics (JMC): 28nm FD-SOI is a pretty exciting technology, allowing better design optimization (for higher speed and power efficiency) than traditional bulk technologies, still reusing most of manufacturing bricks of planar 28nm LP technology and the same design flow and methodology.

Adoption of 28nm FD-SOI for ST-Ericsson’s NovaThor has not introduced any major difficulty in its design, and the FD-SOI version has been taped out shortly after the Low-Power bulk version. Of course special care has been dedicated to further optimize power, exploiting FD-SOI exceptional flexibility and low-power capabilities.

On the manufacturing side, FD-SOI does not introduce additional complexity: on the contrary, process steps are reduced and thus cycle time.

ASN: Can you talk about the results you expect to see or have seen in the chip? Is there anything about it, or perhaps about the ARM core in particular, that makes it especially well-suited to FD-SOI? Is there anything about the transistor back-biasing capability (which enables significant performance enhancements and power optimization) in the design that makes it challenging to manufacture?

JMC: The wide supply range (ranging from 1.2V down to 0.6V) with excellent performance, and extended back-biasing capability (allowing dynamic modulation of the transistor threshold voltage) offered by 28nm FD-SOI technology have allowed us to exploit the ARM implementation to offer an improved maximum frequency and reach an overall power reduction for the various operating modes of the SoC.

About back biasing, this is a standard feature of FD-SOI technology with no particular challenges for manufacturing. Of course, its dynamic usage to optimize operating points for power (or speed) requires an appropriate device architecture to fully benefit from it.

ASN: In the press, STMicroelectronics has indicated that the 28nm FD-SOI has better power and performance than the industry’s first-gen bulk 22nm FinFETs. Would you say that your choice of FD-SOI puts you in a position of strength, in that you’ll have the mobile industry’s leading technology for 28nm and a choice of mature technologies at 14nm?

JMC: 28nm FD-SOI technology is a unique offer in the SOC industry, allowing the introduction of a fully-depleted technology with a low-cost solution and in a timely manner.

28nm FD-SOI is a planar technology derived from 28nm LP bulk technology, with the same design rules and allowing direct layout reuse (or simplified porting) of basic building blocks and IPs, benefiting from inheriting their maturity level. Also on the manufacturing side, 28nm FD-SOI technology uses the same equipment as Low Power bulk CMOS in a simplified process flow. In ST/Crolles facility we are reaching yield levels comparable to 28nm LP bulk ones, proving that FD-SOI process does not introduce major yield detractors.

A smooth library and IP migration flow coupled with rapid availability for manufacturing is driving the success of this 28nm technology.

Looking at the technology roadmap, the same incremental step for the 14nm node is under development and is on track.

The STMicroelectronics fab in Crolles, France. (Photo credit: Artechnic)

ASN: The plan was to start production in your fab in Crolles, then shift to GlobalFoundries for high-volume production in 2013 — is this still the schedule? From a manufacturing standpoint, what does it take to get a fab ready for FD-SOI production (does it take much longer than a typical bulk scaling transition)? Are there any special tools or other preparations needed?

JMC: For manufacturing, 28nm FD-SOI technology uses the same toolset as for 28nm LP bulk. Process development is complete, and ST/Crolles fab is now working to bring yield at production levels and complete the qualification of the technology, as done for any other.

Phase-in of the technology at GlobalFoundries is planned to start Q1 2013, with process qualified and with production level yield foreseen for Q4 2013.

The ST Crolles fab is highly automated, and already runs a broad mix of products in addition to the new FD-SOI chips. The accumulated assets the company has invested in this fab will increase capacity to 4500 wafers/week by the end of 2014. (Photo credit: Artechnic)

ASN: Let’s talk about the Crolles fab for a minute. Although it may be considered small compared to the big pure-play foundries, some aspects you share with the big foundries – like a large mix of product and advanced automation, right?

JMC: Crolles’ technology mix encompasses Advanced CMOS 28/40 nm, Imaging Sensors, embedded Non Volatile Memories starting at 55nm for Microcontroller and Analog on CMOS 110nm. This mix optimizes very well the accumulated assets we have invested in this Fab toward 4500 wafers week capacity over the next two years.

ASN: How do you see the impact of STMicroelectronics’s decision on the industry? Do you expect others to follow? Will other companies be able to leverage your technology at your foundry partners?

JMC: We would like very much for others to follow us. Through GlobalFoundries, ST is making its FD-SOI technology available to anyone in the microelectronics industry. The ST wide set of silicon-proven 28nm foundation libraries and IPs, encompassing not only basic libraries (std-cells, srams, I/Os) but also complex AMS IPs, is also available to be licensed to those customers aiming for quick access to the technology.

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Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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The 38th annual SOI Conference is coming right up. Sponsored by IEEE Electron Devices Society, this is the only dedicated SOI conference covering the full technology chain from materials to devices, circuits and system applications.

Chaired this year by Gosia Jurczak (manager of the Memories Program at imec), this excellent conference is well worth attending. It’s where the giants of the SOI-related research community meet the leading edge of industry. But there are also excellent courses for those new to the technology. And it’s all in an atmosphere that’s at once high-powered yet intimate and collegial, out of the media spotlight.

This year it will be held 1-4 October at the Meritage Resort and Spa, a Napa Valley luxury hotel and resort, set against rolling hills with its own private vineyards. Finding the right spot for this conference is key. One of the things that people really like about it is that in addition to the excellent speakers and presentations, the locations are conducive to informal discussions and networking across multiple fields. This year’s spot looks like the perfect setting, with easy access to Silicon Valley.

The 2012 IEEE SOI Conference will be held October 1-4 at the Meritage Resort and Spa in Napa Valley, California. (Photo Credit: Rex Gelert)

The Conference includes a three-day Technical Program, a Short Course, a Fundamentals Class, and an evening Panel Discussion. Here’s a look at what’s on tap for this year.

(You can get the pdf of the full program & registration information from the website.)

THE PAPERS

ARM’s SOI guru Jean-Luc Pelloie chaired this year’s Technical Program committee, which selected 33 papers for the technical sessions. There will also be 18 invited talks given by world renowned experts in process, SOI device and circuits design and architectures and SOI-specific applications like MEMS, high temperature and rad-hard.

Here’s a rundown of the sessions:

1. Plenary: talks by Soitec and ARM
2. Fully-Depleted SOI: topics include Ground Plane Optimization for 20nm, strain, process & design considerations. GF will present the foundry’s perspective on the move to 28nm FD-SOI and beyond. Also contributors from ST, Leti, Soitec, IBM, GSS/U.Glasgow and more.
3. FinFET and Fully Depleted SOI: topics include Tri-Gate, SOI-FinFET, Flash Memory, strain solutions, flexible Vth. Contributors include Leti, AMD, Soitec, Synopsys, imec, UCL, AIST and UCBerkeley.
4. Poster session: from universities & research institutes supported by industry (IBM, Samsung, etc.)
5. RF and Circuits: topics include high-performance RF, tunable antennas, TSVs. Contributors include Skyworks, ST, Xilinx and leading universities in China.
6. Memory: contributors from IMEP, ST, TI, R&D institutes and academia
7. Novel Devices and Substrate Engineering: topics include nanowires, strained SOI wafers and III-V devices, with contributions from Tokyo Tech, Toshiba, IBM, Soitec, Leti and more.
8. MEMS and Photonics: includes an invited talk by U. Washington on their Intel-sponsored photonics foundry service and papers from MIT and more.
9. RF and Circuits: covering high-voltage, high-temperature, with contributions from Cissoid, IBM, UCL and more.
10. Hot Topics: Fully-Depleted Technology and Design Platforms: six invited talks by ST, IBM, CMP, GF, UC Berkeley and the SOI Consortium.
11. Late News: tbd, of course…

THE COURSES & PANEL

Short course: Design Enablement for Planar FD & FinFET/Multi-gates (chaired by UCL & Leti) The conference kicks off on Monday with six sessions by experts in technological trends, the physics of fully depleted devices, technology design kits as well as digital, analog and RF designs specific for FD-SOI.

The fundamentals course: FinFET physics (chaired by Intel): on Wednesday afternoon, three hour-long sessions will give comprehensive insights into the physics and processes related to multi-gate FETs.

Panel: Is FinFET the only option at 14nm? (chaired by Soitec) Following the always-popular Wednesday evening cookout, the panel discussion is a lively, favorite event. This year’s invited distinguished experts — Scott Luning (GF), Ali Khakifirooz (IBM), Yang Du (Qualcomm). and moderator Sorin Cristoloveanu (Grenoble Institute of Technology) – will share their views on the industry’s FinFET roadmap.

All in all, it’s a great event. If you go, why not share your impressions on Twitter with #SOIconf12, @followASN and @IEEEorg? And of course ASN will follow-up with summaries of the top papers in our PaperLinks section. See you there?

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Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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SOI in general and FD-SOI in particular were hot topics at this year’s Semicon West in San Francisco. A panel discussion by industry thought-leaders gathered to discuss the current challenges facing the mobile industry was among the highlights.  It featured an impressive line-up of key players from the ecosystem at the forefront of fully-depleted, SOI based technologies, including:

• ARM: Ron Moore – Director of Strategic Accounts Marketing, Physical IP Division
• GlobalFoundries: Subramani Kengeri – Vice President of Design Solutions
• IBM: Gary Patton – Vice President of the Semiconductor Research and Development Center
• SOI Industry Consortium: Horacio Mendez – Executive Director
• Soitec: Steve Longoria – Senior Vice President of World Wide Strategic Business Development
• STMicroelectronics: Philippe Magarshack – Technology Research and Development Group Vice President
• UC Berkeley: Chenming Calvin Hu, Ph.D. – TSMC Distinguished Professor at the University of California at Berkeley

FD-SOI figured prominently in a panel on mobile challenges held during Semicon West '12. Left to right: C. Hu (UCBerkeley); R. Moore (ARM); H. Mendez (SOI Consortium); G. Patton (IBM); P. Magarshack (ST); S. Kengeri (GF); S. Longoria (Soitec)

Setting the scene, Soitec’s Longoria noted that, “Our industry is now driven by SOCs (where in the past it was CPUs) and we are on much shorter product cycles driven by consumer applications.”

As the first to be bringing out products based on ultra-thin layers of both SOI and insulator, ST’s Magarshack spoke extensively about their planar FD-SOI technology, which will be taping out at 28nm this summer.  He said that they were very confident and would be sharing the results at the end of the year.  He also emphasized their full commitment and close work with GF to enable the ecosystem, which was echoed in comments by GF’s Kengari.

With respect to 28nm, said Mendez of the SOI Consortium, “…the analysis says the cost [of FD-SOI] is equivalent to or even lower [than bulk silicon].”

IBM’s  Patton concurred, saying that, “When you’re dealing with an FD-SOI wafer, we see a big key advantage in manufacturability and time to market.”

Asked how FD-SOI would impact end-users, ARM’s Moore responded that mobile is about saving power.   FD-SOI provides a low-power bedrock, and with the headroom, the back-biasing option lets you add incredible performance.  “We see a valuable flow with FD-SOI & FinFET from devices down to servers,” he said.

In conclusion, UCBerkeley’s Hu said, “I’m very confident FD-SOI and FinFET are going to serve the industry quite well.”

The panel was followed by a great party held by leading SOI wafer manufacturer Soitec, to celebrate their 20th anniversary.

Earlier in the day, the show’s TechXpot series lead off with Enabling Sub-22nm with New Materials and Processes.  It was packed – with all the chairs taken, people were sitting on the floor in the aisles and crowded four-deep all around the edges. In his presentation on the  “Convergence of Engineered Substrates and IC Devices for Mobile Applications”,  Soitec CTO Dr. Carlos Mazure reminded us that mobile is really many technologies: in addition to the digital side, there’s RF, imaging, MEMS and memories – all of which can (and many do) benefit from SOI and other advanced engineered substrates. They’re not all on the leading edge, but when it comes to battery life, they all count.

At another presentation, Leti’s FD-SOI Manager with the IBM Alliance Maud Vinet covered their leading-edge research on FD-SOI.  She says that they’ll be presenting exciting results at IEDM in December, so watch this page for that.

All in all, it was a good show for the SOI ecosystem, full of energy and renewed enthusiasm.

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Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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The researchers at Leti working on FD-SOI have extremely deep expertise in it. One of the areas they’ve looked at is performance boosters. With the interest in FD-SOI rapidly increasing on the heels of the recent ST-GF announcement, their work becomes even more timely.

A key Leti team wrote a summary of some recent strain work, which first appeared as part of the Advanced Substrate News special edition on FD-SOI industrialization.  In case you missed it there, here it is again.

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Leti: Adding Strain to FD-SOI for 20nm and Beyond

By Olivier FAYNOT, Microelectronic Section Manager, and Francois ANDRIEU, senior research engineer at CEA-LETI.

The outstanding electrostatic performance already reported for planar FD-SOI technology can be improved by the use of ION boosters in order to target-high performance applications, as already demonstrated in the past.

Figure 1: Stressor options for FD-SOI technology

As illustrated in Figure 1, strain can be incorporated at various places in the transistor:

• In the channel through the use of c-SiGe for PMOS devices and strained SOI (sSOI) material for NMOS.
• In the source and drain region with the use of SiGe or SiC for P and NMOS respectively.
• In the Middle-of-Line process with the deposition of tensile or compressive Contact Etch Stop Layers (t- or c-CESL).

First, it is worth noting that local stressors are often more effective on FD-SOI than on bulk at a given geometry because of the mechanical properties of the buried SiO2, which is less stiff than Si[1].

We have assessed different boosters on the FD-SOI architecture. The results are summarized in Figure 2.

For NMOS, one can see that sSOI is the more promising stressor with an ION improvement of 20-35 % for wide devices; and, it can increase up to 50 % for W = 50 nm narrow transistors[2] [1]. Our preliminary results let us predict a better scalability for sSOI than for t-CESL or SMT. Moreover, the compatibility of sSOI was already proved (even if the ION-boosts are not always totally additive) with t-CESL[3] for NMOS and with rotated substrates[2], e-SiGe[4], SiGe channels[5] and (110) substrates[6] for pMOS.

For pMOSFETs, there are several options to enhance the ION, the simpler being the 45° rotated substrates with a 8 % boost[1] and r-SiGe with a 18 % improvement by an access resistance reduction (37 % if a strain can also be generated into the channel)[4]. Once again, the scalability of the global boosters is certainly better than for the local ones (c-CESL and e-SiGe).

Figure 2: Efficiency of stressor techniques for N & PMOS

In conclusion, thanks to all the experiments already run, we are confident in the fact that strain can be incorporated in the planar FDSOI architecture, thus boosting performance even further at 20 nm and beyond.

NOTE: This article was adapted from the Leti presentation, “FD-SOI strain options for 20 nm and below”, given at the SOI Consortium’s 6th FD-SOI Workshop. The complete presentation is available at www.soiconsortium.org.

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References:

[1] C. Fenouillet-Beranger, L. Pham Nguyen, P. Perreau, S. Denorme, F. Andrieu, O. Faynot, L. Tosti, L. Brevard, C. Buj, O.Weber, C. Gallon, V. Fiori, F. Boeuf, S. Cristoloveanu, T. Skotnicki, “Ultra compact FDSOI transistors (including Strain and orientation) processing and performance”, ECS Transaction, 2009.

[2] S. Baudot, F. Andrieu, O. Faynot, J. Eymery, “Electrical and diffraction characterization of short and narrow MOSFETs on Fully Depleted strained Silicon-On-Insulator (sSOI)”, Solid State Electronics, 2010.

[3] F. Andrieu, C. Fenouillet-Beranger, O. Weber, S. Baudot, C. Buj, J.-P. Noel, O. Thomas, O. Rozeau, P. Perreau, L. Tosti, L. Brevard, O. Faynot, “Ultrathin Body and BOX SOI and sSOI for Low Power Application at the 22 nm technology node and below”, invited talk at SSDM, 2009.

[4] S. Baudot, F. Andrieu, O. Weber, P. Perreau, J.F. Damlencourt, S. Barnola, T. Salvetat, L. Tosti, L. Brévard, D. Lafond, J. Eymery, O. Faynot, “Fully-Depleted Strained Silicon-On-Insulator p-MOSFETs with Recessed and Embedded Silicon-Germanium Source/Drain”, 2010.

[5] F. Andrieu, T. Ernst, O. Faynot, Y. Bogumilowicz, J.-M. Hartmann, J. Eymery, D. Lafond, Y.-M. Levaillant, C. Dupré, R. Powers, F. Fournel, C. Fenouillet-Beranger, A. Vandooren, B. Ghyselen, C. Mazure, N. Kernevez, G. Ghibaudo and S. Deleonibus, “Co-integrated dual strained channel on fully depleted sSDOI CMOSFETs with HfO2 /TiN gate stack down to 15 nm gate length”, IEEE SOI Conference, p. 223-5, 2005.

[6] T. Mizuno, N. Sugiyama, T. Tezuka, Y. Moriyama, S. Nakaharai, S. Takagi, ”(110)-Surface Strained-SOI CMOS Devices”, IEEE Transaction of Electron Devices, 52, 3, p.367, 2005.

Posted by Adele Hars, Editor-in-Chief, Advanced Substrate News

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As I blogged here on SemiMD last week, STMicroelectronics has announced that to supplement in-house production at their fab in Crolles, the company has tapped GlobalFoundries for high-volume production of 28nm then 20nm FD-SOI mobile devices.  ST will also open access to its FD-SOI technology to GlobalFoundries’ other customers.  High-volume manufacturing will kick off with ST-Ericsson’s ARM-based 28nm NovaThor.

Prior to the announcement, the STM published a white paper explaining why they were forging ahead on FD-SOI.  It’s an excellent paper, providing benchmarks and design considerations.

As they explained in the Executive Summary: “Planar FD is a promising technology for modern mobile and consumer multimedia chips. It combines high performance and low power consumption, complemented by an excellent responsiveness to power management design techniques. The fabrication process is comparatively simple and is a low-risk evolution from conventional planar bulk CMOS – and there is little disruption at the design level, too. At 28nm, we find that planar FD more than matches the peak performance of “G”-type technology, at the cost and complexity of a low-power type technology, with better power efficiency across use cases than any of the conventional bulk CMOS flavors. Looking further, for 20nm and 14nm, we believe planar FD will be extremely competitive with respect to alternative approaches in terms of performance and power, while being both simpler and more suited to low-power design techniques. In short, a better choice for the type of SOC we offer. Planar fully depleted silicon technology will be ready as early as 2012 to compete in the forthcoming superphones era and in many other consumer segments.”

With the ST/GF news that other GF customers will have access to the ST technology, those in the fabless community will no doubt be wanting to learn more about what’s on offer.  If you have time, you can download the entire ST white paper from the SOI Consortium: Planar fully depleted silicon technology to design competitive SOC at 28nm and beyond.

The ST team that wrote it also wrote a summary version, which first appeared as part of the Advanced Substrate News special edition on FD-SOI industrialization.  In case you missed it there, here it is again.

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ST White Paper Excerpts: Planar Fully-Depleted Silicon Technology to Design Competitive SOCs at 28nm and Beyond

By Philippe FLATRESSE, Program Manager for Fully Depleted SOI Technology, STMicroelectronics; Giorgio CESANA, Director of Technology Marketing at STMicroelectronics; and Xavier CAUCHY, Digital Applications and Strategic Marketing Manager at Soitec.

Having identified that conventional planar bulk CMOS would not meet all the requirements of mobile and consumer multimedia System-on-Chip (SOC) ICs in the coming years, STMicroelectronics assessed alternative options. It is possible to propose a 28nm planar FD solution available as a second generation shortly after readiness of traditional 28nm on bulk silicon, with better time-to-market than waiting for availability of the 20nm node. It is also an excellent learning step to prepare a 20nm planar FD process. Our evaluations show that 20nm planar FD has also a very competitive potential performance-wise vs. FinFET for System-on-Chip applications.

Figure 1: ST’s planar FD device structure features (notional perspective, notional cross-section, TEM cross-section)

Technology overview:

• Immunity to Short Channel Effects and variability (no channel doping, so no Random Doping Fluctuations / RDF)

• For the 28nm node, the selected BOX thickness is 25nm.

• Ultra-thin BOX advantages include:

  - further improved electrostatic control and relaxed thinness requirement of the top silicon,

  - enables back-biasing through the BOX,

  - enables the implantation, during the fabrication process, of heavily doped “ground planes” or “back-planes” under the BOX, for improved electrostatics and/or VT adjustment and/or best-efficiency of back-bias,

  - brings the ability, during the fabrication process, to locally remove the top silicon and BOX to reach the base bulk silicon and co-integrate a few (non geometry-critical) devices on Bulk with devices on SOI – with a small step height between an SOI zone and a Bulk zone, compatible with lithography tools.

• BOX offers total dielectric isolation of the very thin active layer and naturally ultra-shallow junctions, leading to lower source/drain capacitance, lower leakage and latch-up immunity.

Planar FD technology allows several methods for setting the threshold voltage VT, including engineering the gate stack work function, trimming the gate length and other process engineering techniques. Thanks to this, STMicroelectronics’ 28FDSOI technology is capable of offering 3 VTs (HVT, RVT, LVT), as in traditional bulk CMOS technologies.

Circuit-Level Benchmarking

To assess how the improved planar FD-SOI transistor characteristics translate at the circuit level, STMicroelectronics has benchmarked a number of representative IP blocks, including an ARM Cortex-A9 CPU core. To that aim, we have extracted logic critical paths with associated RC parasitics from placed-and-routed designs and have re-characterized them by swapping 28nm traditional bulk CMOS transistor SPICE models with 28nm planar FD SPICE models.

With test chips in our 28nm planar FD technology becoming available, we are demonstrating that the models predict well the silicon behavior. We are therefore confident that the benchmarks presented below are reliable and will be matched by SOC implementations.

The benchmarks compare the merits at the 28nm node of ST’s planar FD technology (“28FD”) with a state-of-the-art Low-Power technology (“28LP”) and a more performance-oriented, state-of-art General Purpose technology (“28G”). They are all based on evaluation of an ARM Cortex-A9 core. The analysis focuses on the higher end of the range of operating frequencies found in a SOC, since modern mobile and consumer multimedia demand high performance from their master CPU (for example, a Cortex-A9 or the forthcoming A15).

Performance at nominal Vdd : best speed/leakage trade-off: 28FD consistently outperforms both 28LP and 28G (Figure 2).

Figure 2: Best operating frequency for any class of leakage (TT process, 85C)

Excellent speed/leakage ratio maintained at reduced Vdd : reducing Vdd is a very good way to save dynamic power. It is therefore realistic to envisage building 28FD chips that match 28G or 28LP performance at a fraction of the power consumption.

Leading-edge performance across the full Vdd range: 28FD exhibits outstanding performance at all practical Vdd values. In particular, when maximum circuit speed is sought, only the low- and ultra-low-VT flavors of 28G compare with 28FD LVT; however they are much leakier and more limited in terms of, e.g., Vdd overdrive they can withstand without reliability concerns.

Best Power Efficiency Across Use Cases: the 28FD technology is power-efficient across the full Vdd and target frequency range (Figure 3). Contrary to G-type technology, with 28FD a given logic circuit that is power-efficient with Vdd set to reach a certain operating frequency (say, 2GHz range) remains efficient with Vdd set for a different target frequency range (e.g., sub-1.5GHz).

Figure 3: Power efficiency across all use cases (TT process, WC temp)

Focus on SRAM: The bitcells proposed in 28FD technology have very competitive cell current (Icell) vs. standby current ratio, which is representative of the performance/leakage power trade-off for SRAM arrays (Figure 4). This is true for all bit cells flavors: high-density and low-leakage oriented, or high-speed oriented. The footprint of the 4 bitcells proposed in 28FD is the same as that of the 4 bitcells proposed in 28LP.

Figure 4: SRAM memory bit cells performance/leakage. The power supply of 28FD SRAM arrays can be lowered by 100mV from nominal and still match the performance of 28LP SRAM arrays operated at nominal Vdd, while offering a 2x to 5x reduction in leakage power.

Commonalities with 28nm LP Bulk

STMicroelectronics’ strategy when developing the 28nm planar FD technology has been to reuse as much as possible the 28nm low-power bulk CMOS process.

Overall, the Back-End is 100% identical to the traditional 28nm bulk low-power CMOS process, and the Front-End of Line (FEOL) is 80% common with that same process.

The planar FD process saves about 10% of the steps required to fabricate the chips on the wafers. This approximately offsets the cost overhead of the starting wafers. As a result, the 28nm planar FD technology matches the cost of a conventional low-power technology while delivering extremely competitive performance.

Design Considerations

Designing on planar FD requires specific extraction deck and SPICE models. Apart from that, the design flows, methodologies and tools do not need any adaptation that would be specific to planar FD (Figure 5).

Figure 5: ST’s SOC implementation flow outline

SPICE Models: SPICE compact models have been developed for accurately representing planar FD transistors. The model we use is now integrated in all major commercially available simulators, such as Mentor’s ELDO, Synopsys’ HSPICE and XA or Cadence’ SPECTRE. A model card has been extracted for all transistors and other devices available in our 28nm planar FD technology.

Flow and Design Platform: With adequate SPICE models integrated in the PDK, the design flow is identical to that used with conventional 28nm Bulk CMOS technology. We have developed a full design platform for SOC, re-using work done for 28nm Bulk. It consists of standard cell libraries (multi-channel and multi-VT) with power management elements (power switches, level shifters etc.), embedded memories, analog foundation IP (such as PLLs and the likes) and specialty IP (Antifuse etc.).

A design platform developed for bulk CMOS technology can be ported to planar FD by re-characterization using planar FD SPICE models, which we have done for a variety of back-biasing conditions. Only a limited number of critical IPs need to be tuned or redesigned: Analog IP, IOs, Fuse.

At the SOC level, migrating an existing design from bulk to planar FD represents an effort comparable to half-node migration. It brings very worthwhile benefits at reasonable efforts.

All techniques used in low-power designs are applicable to planar FD. Those that can be enhanced with planar FD include: multi-VT, power switches, reverse and forward body bias, and voltage scaling.

Back-biasing consists of applying a voltage just under the BOX of target transistors. Doing so changes the electrostatic control of the transistors and shifts their threshold voltage VT, to either get more drive current (hence higher performance) at the expense of increased leakage current (forward back-bias, FBB) or cut leakage current at the expense of reduced performance. While back-bias in planar FD is somewhat similar to body-bias that can be implemented in bulk CMOS technology, it offers a number of key advantages in terms of level and efficiency of the bias that can be applied.  Back-biasing can be utilized in a dynamic way, on a block-by-block basis. It can be used to boost performance during the limited periods of time when maximum peak performance is required from that block. It can also be used to cut leakage during the periods of time when limited performance is not an issue. In other words, back-bias offers a new and efficient knob on the speed/power trade-off.

Perspectives

28nm: We expect to sign-off designs breaking the 2GHz barrier under worst-case conditions, in a power-efficient and cost-efficient way. For lower performance targets, there is also the opportunity to design ultra-low-power chips that can fulfill their functional specifications using a very low Vdd, for example in the 0.6-0.8V range. The Process Design Kit (PDK) is available, targeting the technology to be open for risk production by mid-2012.

20nm: We intend to scale our planar FD technology to 20nm, introducing a number of improvements to continue pushing the performance and retain a low power consumption. The objective is to bring up a solution that will improve on what mobile-optimized planar bulk CMOS will achieve, and will be extremely competitive vs. potential FinFET-based approaches for SOC – while keeping a simple and cost-efficient approach. The design rules will be compatible with 20nm bulk CMOS. This technology will bridge the gap to 14nm and provide an interesting alternative to the cost and complexity of introducing Extreme-UV and FinFET structures. Evaluation SPICE models are available, and full PDK is scheduled by end of 2012, with risk production for 13Q3.

14nm: Based on the assessments we have performed, we are confident that the planar FD technology is shrinkable to 14nm. Silicon and buried oxide thickness will need to be reduced to within limits that wafer manufacturers and CMOS process technology can handle.