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Posts Tagged ‘MonolithIC’

Qualcomm: Scaling down is not cost-economic anymore – so we are looking at true monolithic 3D

Monday, June 16th, 2014

By Zvi Or-Bach, President and CEO of MonolithIC 3D Inc.

Over the course of three major industry conferences (VLSI 2013, IEDM 2013 and DAC 2014), executives of Qualcomm voiced a call for monolithic 3D “to extend the semiconductor roadmap way beyond the 2D scaling” as part of their keynote presentations.

Karim Arabi, Qualcomm VP of Engineering, voiced the strongest support and provided many details of monolithic 3D’s role, in his keynote at this year’s DAC. A good summary was posted at the Tech Design Forums site under the title “3D and EDA need to make up for Moore’s Law, says Qualcomm.” In this blog, I’ll highlight some of the very interesting quotes from Arabi’s keynote: “Qualcomm is looking to monolithic 3D and smart circuit architectures to make up for the loss of traditional 2D process scaling as wafer costs for advanced nodes continue to increase. One of the biggest problems is cost. We are very cost sensitive. Moore’s Law has been great. Now, although we are still scaling down, it’s not cost-economic anymore”

Qualcomm is not the only fabless company voicing its concern with cost. Early in 2013 Nvidia said it is “deeply unhappy” and executives of Broadcom followed suite. The following chart, presented by ARM, illustrates it nicely.

But it seems that the problem is even more severe than that. In our blog Moore’s Law has stopped at 28nm we examined the expected increase of SoC cost due to poor scaling of embedded SRAM (eSRAM). We should note that the chart above, like many others, is about the cost per transistor associated with dimensional scaling. Escalating lithography cost causes escalating wafer cost, which neutralizes the 2X transistor density increases.

Yet eSRAM scales far less than 2X and, accordingly, for most SOCs, scaling would be even more costly. This issue has been confirmed again with the recent VLSI 2014 paper “10-nm Platform Technology Featuring FinFET on Bulk and SOI” by Samsung, IBM, STMicroelectronics, GLOBALFOUNDRIES and UMC. They presented that the size of their 10nm bitcell is 0.053 µm², which is only 25 percent smaller than the 0.07 µm² reported for 14nm bitcell size. One should expect that an additional area penalty would occur for effective use in large memory blocks, as reported even for 14nm, which could bring the effective SRAM scaling to only about 15 percent, a long way from the 50 percent required to neutralize the escalating wafer costs.

However, cost is not the only issue that forced Qualcomm to consider monolithic 3D. Quoting Arabi:

“Interconnect RC is inching up as we go to deeper technology. That is a major problem because designs are becoming interconnect-dominated. Something has to be done about interconnect. What needs to be done is monolithic three-dimensional ICs. Through-silicon vias and micro bumps are useful where you need I/Os … But they are not really solving the interconnect issue I’m talking about … So we are looking at true monolithic 3D. You have normal vias between different stacks. Then interconnect lengths will be smaller than with 2D. If we can connect between layers the delay becomes smaller.”

The interconnect issue was also addressed at IEDM 2013 by Geoffrey Yeap, Qualcomm VP of Technology, in his invited talk:

“As performance mismatch between transistors and interconnects continue to increase, designs have become interconnect-limited. Monolithic 3D (M3D) is an emerging integration technology poised to reduce the gap significantly between transistors and interconnect delays to extend the semiconductor roadmap way beyond the 2D scaling trajectory predicted by Moore’s Law.”

Yeap provided the following chart for the growing gap between transistor delay and interconnect delay:

Arabi DAC 2014 keynote was also reported on Cadence’s website, which provides our final Arabi quote for this blog: Qualcomm is looking at “monolithic” 3D-ICs that use normal vias between stacked dies. This can provide a one-process-node advantage along with a 30 percent power savings, 40 percent performance gain, and 5-10 percent cost savings.

Clearly, monolithic 3D integration has a very important role in the future of the semiconductor industry. It is therefore fitting that the traditional IEEE conference on SOI has extended its scope and now calls itself S3S: SOI technology, 3D Integration, and Subthreshold Microelectronics. The 2014 S3S conference is scheduled for October 6-9, 2014 at the Westin San Francisco Airport. This would be a great opportunity to learn more about monolithic 3D technology, with five invited presentations covering topics from design tools to monolithic 3D NAND and other 3D memories. CEA Leti will present their work on CMOS monolithic 3DIC, and researchers from MIT and Stanford will present manufacturing monolithic 3D devices with materials other than silicon.

Blog Review: November 25, 2013

Monday, November 25th, 2013

Zvi Or-Bach, president and CEO of MonolithIC 3D, blogs about a recent announcement by Intel CEO Brian Krzanich on company expansion focused on a foundry plan. Or-Bach said that if Intel could keep the traditional 30% cost reduction per node from 28nm to 10nm, and the foundry’s cost per transistor is staying flat, then Intel would be able to provide their foundry customers SoC products at a third of the other foundries cost, and accordingly Intel should be able to do very well in its foundry business.

Vivek Bakshi, EUV Litho, Inc. reports on work presented at the 2013 Source Workshop (Nov 3-7, 2013, Dublin, Ireland), including data on the readiness of 50 W EUV sources to support EUVL scanners. At the meeting, keynoter Vadim Banine of ASML said that 50 W EUV sources have now demonstrated good dose control and are now available for deployment in the field. ASML also presented data on the feasibility of source power of 175 W at the first focus (720 W at source), and utilizing new, protective cap layers to give collectors six months of life.

At the GaTech Global Interposer Technology Workshop (GIT) in Atlanta, the pervasive theme appeared to be whether a change in substrate is required to lower overall costs and help drive HVM (high volume manufacturing) applications. Phil Garrou reports on the workshop, including presentations from Ron Huemoeller of Amkor and David McCann of GLOBALFOUNDRIES.

Pete Singer provides a preview of a special focus session at the upcoming IEEE International Electron Devices Meeting (IEDM), scheduled for December 9 – 11, 2013. The session covers many of today’s hot topics: memory, LEDs, silicon photonics, interposers, SOI finFETS and 450mm.

Dr. Lianfeng Yang of ProPlus Design Solutions, Inc., blogs that these days, circuit designers are talking about the increasing giga-scale circuit size. Semiconductor CMOS technology downscaled to nano-scale, forcing the move to make designing for yield (DFY) mandatory and compelling them to re-evaluate how they design and verify their chips.

Blog Review November 11, 2013

Monday, November 11th, 2013

Karen Savala of SEMI notes that the semiconductor industry is uncharted waters without the benefit of a GPS system. She says mega-mergers, massive supply chain investments by manufacturers and governments, new consortia and collaboration models are changing the rules for everyone in the ecosystem. Pervasive Computing, the theme of this blog post, is also the theme for the upcoming Industry Strategy Symposium (ISS), to be held January 12-14, 2014 in Half Moon Bay, California.

In Karen Lightman’s MEMS Industry Group blog, she turns the reins over to Silex Microsystem’s Peter Himes, vice president marketing & strategic alliances. Peter reflects on MEMS and while other might lament at the conundrum of the uniqueness of all MEMS process, Peter instead sees opportunity. In this example he describes Silex’s partnership with A.M. Fitzgerald and Associates and their Rocket MEMS program.

Phil Garrou covers several topics related to 3D integration in this week’s blog: A new report from Yole on flip chip (FC) technology, ASE’s report ASE – Board Level Reliability of Bump on Polymer (BoP) WLCSPs, and chip embedding at IMS.

Should the lifetime of EUV optics be a concern? Upon hearing about how EUV sources contaminate the optics inside the tool, Pete Singer blogs that there still must be lots of questions about the ultimate cost of ownership and how that will compare to double and triple patterning approaches with 193nm immersion.

Are we using Moore’s name in vain? That question is posed by Zvi Or-Bach, President & CEO of MonolithIC 3D in his blog post, where he notes that dimensional scaling was not an integral part of Moore’s assertion in 1965 – cost was. But dimensional scaling became the “law of the land” and, just like other laws, the industry seems fully committed to follow it even when it does not make sense anymore, he writes.

The Solid State Technology 2014 Editorial Calendar is out, blogs Pete Singer, noting the editorial mission remains that same: we’re dedicated to covering mainstream semiconductor manufacturing technology, with a strong focus on transistors, interconnects and packaging. We also cover other types of advanced electronics, including MEMs, LEDs, displays, bioelectronics, photonics and power electronics.