With back bias,12nm FD-SOI beats 10nm FinFET on performance. This excellent news comes in by way of Peter Clarke of EETimes Europe (read the whole article here). Rutger Wijburg, GM of GloFo’s Dresden fab told him, “If you look at performance with back-bias 22FDX is the same or better than 16/14nm FinFET process. With 12FDX with back bias you get better than 10nm FinFET processes.”
Now in its third year, the 2015 IEEE S3S Conference has evolved into the premier venue for sharing the latest and most important findings in the areas of process integration, advanced materials & materials processing, and device and circuit design for SOI, 3D and low-voltage microelectronics. World-class leading experts in their fields will come to this year’s S3S Conference to present, discuss and debate the most recent breakthroughs in their research.
This year’s program includes:
The conference also features several events tailored for socialization and peer-to-peer discussions, such as the welcome reception, the cookout and the interactive Poster & Reception Session which is a great place to meet new colleagues and learn and exchange insights on technical topics. Enjoy a light snack and a beverage of your choice while meandering around to meet and discuss technical issues with long-time colleagues and make connections with new and influential experts and decision makers in your field.
Take time to visit the local attractions of Sonoma County. Sonoma is well known for outdoor recreation, spas, golf, night life, shopping, culinary activities, arts and music and wineries. It is truly my pleasure to serve as the General Chair of the 2015 Conference. —Bruce Doris
Download the Advance Program
Find all the details about the conference on our website: s3sconference
Click here to go directly to the IEEE S3S Conference registration page.
Click here for hotel information. To be sure of getting a room at the special conference rate book before 18 September 2015.
The DoubleTree by Hilton Sonoma Wine Country, One Doubletree Drive, Rohnert Park, CA 94928
October 5th thru 8th, 2015
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Join the IEEE S3S Conference group on LinkedIn to follow the news — click here or search on LinkedIn for IEEE S3S.
The IEEE SOI-3D-Subthreshold Microelectronics Technology Unified Conference (IEEE S3S) has issued the 2015 Call for Papers.
Now in its 3rd year as a combined event, the 2015 IEEE S3S Conference will take place in Sonoma Valley, CA, just north of San Francisco, October 5-8. This industry-wide event will gather together widely known experts, contributed papers and invited talks on three main topics: SOI technology, subthreshold architectures with associated designs and 3D integration. With its 40-year history, the SOI segment continues as world’s premier conference to present and discuss state of the art SOI technical papers.
ST further accelerates its FD-SOI ROs* by 2ps/stage, and reduces SRAM’s VMIN by an extra 70mV. IBM shows an apple-to-apple comparison of 10nm FinFETs on Bulk and SOI. AIST improves the energy efficiency of its FPGA by more than 10X and Nikon shows 2 wafers can be bonded with an overlay accuracy better than 250nm.
We learned all this and much more during the very successful 2014 IEEE S3S Conference.
The conference’s 40th edition (first created as the IEEE SOS technology workshop in 1975) was held in San Francisco Oct. 6-9. Dedicated to central technologies for tomorrow’s mainstream applications, the event boasted nearly 80 papers presented over 3 days covering conception, design, simulation, process and characterization of devices and circuits.
Many of the talks we heard made it very clear that the Internet-of-Things will be the next big market growth segment. It will be enabled by extremely energy-efficient and low-cost technologies in the field of RF-communications, sensors and both embedded and cloud computing. The program of the conference was very well designed to tackle these topics, starting with the short courses on Energy Efficiency and Monolithic 3D, an RF fundamentals & applications class, a MEMS hot topic session and a strong focus on ultra-low power throughout the SubVt sessions.
The interest of the participants could be seen through an increase in Short Course and Fundamentals Class participation (+20%) compared to last year.
The companies working in the field of RF communications and mobile chips were well represented, including attendees and presenters coming from Broadcom, MediaTek, Murata, Newlans, Qualcomm, RFMD, Skyworks and TowerJazz.
The SubVT portion of the conference featured an extremely strong suite of papers on advancements in subthreshold circuit design including ultra-low-voltage microprocessors, FPGAs, and analog circuits. Additionally, there were sessions on technologies which enable very low voltage computation, such as radiation testing during subthreshold operation, and efficient energy-harvesting devices to allow indefinite operation of IoT systems. A number of talks explored the future of ultra low voltage computing, presenting results from emerging technologies such as Spin Torque Transfer devices and TFETs.
The 3D integration track keeps growing in the conference and is strongly focused on monolithic 3D. A dedicated full day short course was offered again this year, as well as two joint sessions featuring several papers on process integration, design, precision alignment bonders and more. Progress is being made and a lot of interest in this technology is being generated (See the EE Times article).
Planar Fully-Depleted SOI technologies were well represented again this year, in both SOI and Sub-Vt parallel sessions. A full session was also dedicated to FinFETs.
STMicroelectronics and CEA-Leti gave us a wealth of information on:
How to improve your circuit’s efficiency by co-optimizing Vdd, poly-bias and back-gate voltage simultaneously during the circuit design. Picking the correct optimization vector enables you to gain more than 2X in speed or up to 5X in power compared to the non-optimized circuit. (P. Flatresse, “Design Strategy for Energy Efficient SOCs in UTBB FD-SOI Technology” in the “Energy Efficiency” short course). In the same presentation we saw how going to a single-well configuration can help further reduce SRAM’s VMin by 70mV (see graph to the right).
The latest updates on 14nm technology, including an additional 2ps/stage RO delay reduction since the 2014 VLSI results shown last June. This means ROs running faster than 8ps/stage at 10nA/stage of static leakage. The key elements for the 10nm node (sSOI, thinner BOX, replacement gate, next gen. ID-RSD) where also discussed. (M. Haond, “14nm UTBB FD-SOI Technology”).
In the past year we witnessed the foundry announcements for FD-SOI technology offering. Global Foundries very clearly re-stated their interest in the FD-SOI technology, claiming that 28FD-SOI is a good technology for cost sensitive mobile applications, with the cost of 28LP and the performance of 28HPP. However, GF favors a flavor of FD-SOI technology they call Advanced ET-SOI, with similar performance to 20LPM at a reduced cost.
The IEEE S3S Conference Best Paper Award went to Hanpei Koike and co-authors from the National Institute of AIST, for their paper entitled “More than An Order of Magnitude Energy Improvement of FPGA by Combining 0.4V Operation and Multi-Vt Optimization of 20k Body Bias Domains,” presented in the SubVT part of the conference. In this work, an FPGA was fabricated in the AIST SOTB (Si On Thin BOX — which is another name for FD-SOI) process, and demonstrated successful operation down to voltages at and below the minimum energy point of the circuit. A 13x reduction in Power-Delay-Product over conventional 1.2V operation was achieved through a combination of low voltage operation and flexible body-biasing, enabled by the very thin BOX.
On the FinFET side, T.B. Hook (IBM) presented a direct comparison of “SOI FinFET versus Bulk FinFET for 10nm and below”, based on silicon data. This is a very unique work in the sense that both technologies are being developed and optimized by the same teams, in the same fab, with the same ground rules, which enables a real apple-to-apple comparison. SOI comes out a better technology in terms of Fin height control (better performance and ION variability), VT mismatch (lower VMin), output conductance (better analog and low voltage perf.) and reliability. Though external stressors are expected to be more efficient in Bulk FinFETs, mobility measurements are only 10% lower for SOI PFETs and are actually 40% higher for SOI NFETs, because of the absence of doping. The devices’ thermal resistance is higher on SOI, though bulk FinFETs are not as immune to self-heating as planar bulk. Both technologies are still competitive down to the 10nm node, but looking forward, bulk’s advantages will be rendered moot by the introduction of high mobility materials and dimensions shrinking, while SOI advantages will keep getting larger.
Next year, the S3S Conference will be held October 5-8, at the DoubleTree by Hilton Sonoma Wine Country Hotel, Rohnert Park, California.
The organizing committee is looking forward to seeing you there!
Steven A. Vitale is an Assistant Group Leader in the Quantum Information and Integrated Nanosystems Group at MIT Lincoln Laboratory. He received his B.S. in Chemical Engineering from Johns Hopkins University and Ph.D. in Chemical Engineering from MIT. Steven’s current research focuses on developing a fully-depleted silicon-on-insulator (FDSOI) ultra-low-power microelectronics technology for energy-starved systems such as space-based systems and implantable biomedical devices. Prior to joining MIT-LL, Steven was a member of the Silicon Technology Development group at Texas Instruments where he developed advanced gate etch processes. He has published 26 refereed journal articles and holds 5 patents related to semiconductor processing. From 2011 to 2012 Steven was the General Chair of the IEEE Subthreshold Microelectronics Conference, and is on the Executive Committees of the AVS Plasma Science and Technology Division, the AVS Electronic Materials and Processing Division, and the IEEE S3S Conference.
Frederic Allibert received his MS degree from the National Institute for Applied Sciences (INSA, Lyon, France) in 1997 and his PhD from Grenoble Polytechnic’s Institute (INPG) in 2003, focusing on the electrical characterization of Unibond wafers and the study of advanced device architectures such as planar double-gate and 4-gate transistors. He was a visiting scientist at KAIST (Taejon, Korea) in 1998 and joined Soitec in 1999. As an R&D scientist, he implemented SOI-specific electrical measurement techniques (for thin films, multi-layers, high resistivity) and supported the development of products and technologies targeting various applications, including FD-SOI, RF, imagers, and high-mobility materials. As Soitec’s assignee at the Albany Nanotech Center since 2011, his focus is on substrate technologies for advanced nodes. He has authored or co-authored over 50 papers and holds over 10 patents.
*RO = ring oscillator
The 2014 IEEE SOI-3DI–Subthreshold (S3S) Microelectronics Technology Unified Conference will take place from Monday October 6 through Thursday October 8 in San Francisco.
Last year we entered into a new era as the IEEE S3S Conference. The transition from the IEEE International SOI Conference to the IEEE S3S conference was successful by any measurement. The first year of the new conference leading-edge experts from 3D Integration, Sub-threshold Microelectronics and SOI fields gathered and we established a world class international venue to present, learn and debate about these exciting topics. The overall participation at the first year of the new conference grew by over 50%, and the overall quality and quantity of the technical content grew even more.
This year we are looking forward to continuing to enhance the content of the 2014 S3S Conference.
Short courses: Monolithic 3D & Power-Efficient Chip Tech
On Monday, Oct. 6 we will feature two Short Courses that will run in parallel. Short courses are an educational venue where newcomers can gain overview and generalists can learn more details about new and timely topics.
The short course on Monolithic 3D will be a full day deep dive into the topic of three-dimensional integration wherein the vertical connectivity is compatible with the horizontal connectivity (10,000x better than TSV). Already there are extremely successful examples of monolithic 3D Flash Memory. Looking beyond this initial application, we will explore the application of monolithic 3D to alternate memories like RRAM, CMOS systems with silicon and other channel materials like III V. In addition, a significant portion of the short course will be dedicated to the exciting opportunity of Monolithic 3D in the context of CMOS Logic.
The other short course we will offer this year is entitled Power Efficient Chip Technology. This short course will address several key aspects of power-efficiency including low power transistors and circuits. The course will also review in detail the impact of design and architecture on the energy-efficiency of systems. The short course chairs as well as the instructors are world class leading experts from the most prestigious industry and academic institutions.
The regular conference sessions will start on Tuesday Oct. 7 with the plenary session, which will feature presentations from Wall Street (Morgan Stanley Investment Banking), Microsoft and MediaTek. After the plenary session we will hear invited talks and this year’s selection of outstanding papers from international researchers from top companies and universities. The most up to date results will be shared. Audience questions and one on one interaction with presenters is encouraged.
Back by popular demand we will have 2 Hot Topics Sessions this year. The first Hot Topic Session is scheduled for Tuesday Oct. 7th and will feature exciting 3DI topics. The other Hot Topics session is scheduled for Thursday Oct 9 and will showcase new and exciting work in the area of MEMS.
Our unique poster session and reception format will have a short presentation by the authors followed by one on one interaction to review details of the poster with the audience, in a friendly atmosphere, around a drink. Last year we had regular posters as well as several invited posters with very high quality content and we anticipate this year’s poster session to be even better than last years.
We are offering a choice of two different fundamentals classes on Wednesday afternoon. One of the Fundamentals classes will focus on Robust Design of Subthreshold Digital and Mixed Circuits, with tutorials by the worlds leading experts in this field. The SOI fundamentals course is focused on RF SOI Technology Fundamentals and Applications.
Our technical content is detailed on our program webpage.
Panel discussions, cookout & more
Keeping in line with tradition, on Wednesday night we will have a hearty cook out with delicious food and drink followed by the Panel Session entitled Cost and Benefit of Scaling Beyond 14nm. Panel speakers from financial, semiconductor equipment, technology, and academic research institutions will gather along with the audience to debate this timely topic. Although Thursday is the last day of the conference we will have stimulating presentations on novel devices, energy harvesting, radiation effects along with the MEMS Hot Topic Session and Late News Session. As always we will finish the conference with the award ceremony for the best papers.
Our conference has a long tradition of attracting presenters and audience members from the most prestigious research, technology and academic institutions from around the world. There are many social events at the S3S Conference as well as quiet time where ideas are discussed and challenged off line and people from various fields can learn more about other fields of interest from leading experts.
The conference also offers many opportunities for networking with people inside and also outside ones area. The venue this year is San Francisco. We chose this location to attract the regions leading experts from Academia and Industry. If you have free time we encourage you to explore San Francisco which is famous for a multitude of cultural and culinary opportunities.
To take full advantage of this outstanding event, register before September 18!
Special hotel rates are also available from the dedicated hotel registration page.
The committee and I look forward to seeing you in San Fransisco.
– Bruce Doris, S3S General Chair
Over the summer, there have been a number of excellent posts on various sites related to FD-SOI, showing that interest is running ever higher.
But, if you’ve been fortunate enough to have had some vacation time, you might have missed some of them, so here’s a brief listing to help you catch up.
In mid-June, Samsung posted a video of their DAC presentation, Samsung 28nm technology for the next big thing on YouTube. Presented by JW Hwang, Principal Engineer for Samsung Electronics, it runs almost 14 minutes long, with the entire second half devoted to 28nm FD-SOI. Here are some key points made therein:
Samsung DAC ’14 video – process complexity vs. performance/power.
Samsung DAC ’14 video – 28nm FD-SOI is product-proven
Here at ASN, of course, there was the terrific piece by industry expert Handel Jones (IBS) entitled FD-SOI: The Best Enabler for Mobile Growth and Innovation. IBS concludes the benefits of FD-SOI are overwhelming for mobile through Q4/2017. Jones also looks for it to have a useful lifetime through 2020 and beyond for digital designs and through 2030 for mixed-signal designs.
Also in ASN, we covered the SOI Papers at the 2014 VLSI Symposia. Three top SOI-based papers included one that indicates 14nm FD-SOI should match the performance of 14nm bulk FinFETs, and the two on 10nm SOI FinFETS. (In Part 2, we covered the rest of the SOI papers.)
Elsewhere, we saw high-profile, open debate, which is excellent and necessary. Semiwiki has been a great platform for discussion, with a steady flow of FD-SOI articles – many of which generate ferociously active discussions in the comments section. Here’s a round-up of what went on this summer:
Next, check out this interesting post in SemiconductorEngineering by Mary Ann White, director of product marketing for the Galaxy Design Platform at Synopsys. She gives a very informative perspective on “Power Reduction Techniques” (7 Aug. ’14) in bulk planar, FD-SOI and FinFETs. She talks about how biasing in FD-SOI is highly effective, then goes on to summarize various power-reduction techniques by process node. There’s an excellent summary in her graphic (her Figure 2):
There’s also a terrific chart in the same article based on the annual Synopsys’ Global User Survey (GUS), indicating which power techniques are used most in which applications (mobile, automotive, networking, etc.).
If talk on LinkedIn is any indication, the design community in India is very interested in FD-SOI. EE Herald published a much-shared interview with ST’s CAD/design solutions director in India (18 July ’14), entitled FDSOI; The only semiconductor tech to continue Moore’s Law down to 10nm. It gives an excellent overview of the technology, answering some of the basic questions designers are asking.
The following in-depth analysis, an IBS study entitled How FD-SOI will Enable Innovation and Growth in Mobile Platform Sales, concludes that the benefits of FD-SOI are overwhelming for mobile platforms through Q4/2017 based on a number of key metrics. In fact, FD-SOI has the ability to support three technology nodes, which can mean a useful lifetime through 2020 and beyond for digital designs and through 2030 for mixed-signal designs. Here are some of the highlights from the study.
First, let’s consider the markets we’re addressing.
The unit volume of smartphones and tablet computers is projected to reach nearly 3B units in 2020 worldwide. These mobile platforms need to have access to low-cost and low-power semiconductor products, including application processors and modems. Performance must also be enhanced, but this needs to be done within the cost and power consumption constraints.
Mobile platforms need essentially the same performance as notebook computers, but have to rely on much smaller battery capacity. They also need to support high-performance graphics and ever-greater data rates, including the support of 1Gbps when the 5G protocol is tested in 2018. Better cameras demands high-performance image signal processing. 3-D imaging, now under development, will require multiple image sensors. All of this needs to be accommodated with lower power consumption and lower cost.
It is significant that a high percentage of smartphones and tablet computers will be manufactured byChinese companies. Semiconductor technologies that increase battery lifetime without incurring additional costs or potentially providing lower cost can be very attractive to smartphone vendors.
The market requirements are clear, and our detailed analysis of various technology options, including bulk CMOS at 28nm and 20nm and FinFET at 16/14nm, shows FD-SOI is the best option for supporting the requirements of high-volume mobile platforms.
FinFETs have the potential to be in high volume in the future: the key issue is timing. Our analysis indicates that FinFETs have high design costs, along with high product costs. It is not realistic to expect FinFETs to be effective for the low-cost and low-power modems, application processors, and other processor engines for mobile platforms in 2016 and 2017.
FinFETs need to go through two phases in the 2015 to 2016 time frame to reach the point where they are suitable for low power and low cost applications.
In the first phase, they will be used in high-performance products such as processors for servers, FPGAs, graphics accelerators, and other similar product categories. This approach was used in the past for new-generation process technologies, where price premiums were obtained from the initial products. The time frame for the high-performance phase of 16/14nm FinFETs within the foundry environment can be 2015, 2016, and potentially 2017.
The high-performance phase can allow extensive characterization of the 16/14nm process and provide a good understanding of various categories of parasitic so that product yields can become high. There is also the need to establish design flows so that new products can be brought to the market within short design windows. The high priced product phase can position 16/14nm FinFETs to be potentially used in high volume, low cost products at a future time.
The second FinFET phase comprises the ramp-up to high volumes for high end processor engines for mobile platforms. High-end mobile platforms, including tablet computers and smartphones, can provide relatively high volumes for FinFET products if costs are competitive. Modems, application processors, and graphics functionality will be suited to the 16/14nm FinFETs from the foundries in the 2017 to 2018 time frame.
This type of methodical approach in solving the manufacturing challenges at 16/14nm can be applied to 10nm and 7nm FinFETs. There is the need to establish design flows that can yield high gate utilization as well as the ability to obtain high parametric yields. The time frame for the high-volume, low-cost phase of FinFETs can potentially be 2017 or 2018.
With the delays in ramping 16/14nm FinFETs into high volume until potentially 2017 or 2018, an alternate technology is needed to support the next phase of the mobile platform IC product supply, which can give low power consumption and low cost.
FD-SOI: Competitive Positioning
To provide visibly into the options for technology selection, IBS has analyzed projected wafer costs and gate costs for bulk CMOS, FD-SOI, and FinFETs. Considerations include processing steps, masks, wafer costs, die shrink area, tool depreciation and parametric yield. The results are shown in the following figures.
Processed wafer cost comparison for FD-SOI, bulk CMOS and bulk FinFETs at the 28nm through 16/14nm nodes. (Source: IBS)
Gate cost comparison for FD-SOI, bulk CMOS and bulk FinFETs at the 28nm through 16/14nm nodes. (Source: IBS)
The low cost per gate of 28nm wafers in Q4/2016 and Q4/2017 allows this technology node to have a long lifetime. The performance of 28nm FD-SOI is 30% higher compared to 28nm bulk CMOS, with leakage also being 30% lower. There are, consequently, significant benefits in using 28nm FD-SOI compared to 28nm bulk CMOS for the high volume cost- and power-sensitive applications.
Furthermore, the performance of 28nm FD SOI is 15% better than 20nm bulk CMOS, giving 28nm FD-SOI a potentially even longer lifetime.
The gate cost of 20nm FD-SOI is 20% lower than 20nm bulk CMOS, while offering 40% lower power. and 40% higher performance. The higher cost per gate of 20nm bulk CMOS compared to 20nm FD-SOI is due to the higher number of processing and masking steps. There are also parametric yield penalties at 20nm because of difficulties in controlling leakage. Fabless companies that choose 20nm bulk CMOS over 20nm FD-SOI (called 14nm by STMicroelectronics) risk to find themselves with a noncompetitive platform.
14nm FD-SOI (called 10nm by STMicroelectronics) has an almost 30% lower cost per gate than 14nm FinFETs (including 16nm FinFETs) in Q4/2017, which is a major advantage in price-sensitive applications. Power consumption and performance are expected to be comparable between two technologies.
Why the hesitation in using FD-SOI?
While we clearly see that the benefits of FD-SOI, we also recognize that there is an expectation in the semiconductor industry that Intel sets the bar, so if Intel is doing FinFETs, everyone else should, too. The financial metrics of Intel are, however, different from those applicable to the fabless-foundry ecosystem. Intel is obtaining large revenues from its data center processors. And even though the company has promoted its 14nm and Tri-Gate processors for mobile platforms, Intel’s success in this arena has not been outstanding to date. Intel has, however, delayed the high-volume production of its 14nm Tri-Gate from Q4/2013 to H1/2015 because of low yields. The yield challenges that Intel is experiencing at 14nm should be a warning to fabless-foundry companies of the difficulties in ramping 16/14nm FinFETs within relatively short time frames.
Nonetheless, the manufacturing ecosystem is committed to making FinFET successful, so the resources that have been committed to FD-SOI have been limited. There is also reluctance to admit that the decision to adopt FinFET was premature and a thorough analysis of the cost penalties was not done. A similar perspective applies to 20nm bulk CMOS in following the industry pattern for not having a thorough review of the cost and performance impact.
FD-SOI for High-Volume Applications
The benefits of FD-SOI are clear, and as the yield and cost problems related to 20nm bulk CMOS and 16/14nm FinFETs become clearer, it is expected that there will be increased momentum to adopt FD-SOI at 28nm, 20nm (14nm by STMicroelectronics), and 14nm (10nm by STMicroelectronics).
To recap, FD-SOI provides the following benefits for high-volume mobile multimedia platforms:
At 28nm, 20nm, and 14nm technologies, IBS concludes that FD-SOI is superior to competitive offerings for smartphones and tablet computers, and the advantages of FD-SOI extend through Q4/2017. As the supply base for FD-SOI strengthens, FD-SOI is expected to become a key part of the semiconductor supply chain ecosystem for high-volume applications such as smartphones and tablet computers.
The ecosystem in the semiconductor industry should focus on the technologies that optimize the benefits for customers.
A ppt presentation by STMicroelectronics entitled Features and Benefits of 14nm UTBB* FD-SOI Technology is now posted on WeSRCH (click here to view it). It is fairly technical, covering process boosters, modules and innovations, mask sequences, performance and scalability.