Why we need spintronics for the era of

AI and IoT?

Hideo OhnoTohoku University

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Sendai, home of Tohoku University

Tokyo

Population 1,088,593

［City of Sendai］

As of September 2018

Tohoku University is located in Sendai, the largest city in the Tohoku region, well known as an Academic City.

By bullet train 350 kmfrom Tokyo 1.31 hSendai Airport 20 min

Tohoku region(North East region of Japan)

Sendai

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Tohoku University“Research First,” “Open Door,” and “Practice Oriented Research and Education”

3rd National University in Japan, founded 1907 One of the first three Designated National University in 2017

“Sendai is a city most suited for research,and Tohoku University is a force to be reckoned with.” - A. Einstein, 1922

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5G, AI, Big Data, and IoT

https://blog.global.fujitsu.com/jp/2017-12-21/01/ https://amater.as/article/2018/05/18/ai_venture-10/

http://www.bigdata.uni-frankfurt.de/https://www.aapnainfotech.com/iot-beginners-perspective/

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Energy Consumption & Carbon Footprint of the IT Sector

Wednesday, July 18, 2018

Internet-connected devices produce 3.5% ofglobal emissions within 10 years and 14% by2040. (Source: Climate Home News)

Communications industry responsible for 20% ofall the world’s electricity in 2025. (Source: The Guardian)

Data centers consume 1/5 of Earth’s power in2025. (Source: Data Economy).

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IoT 6

Processing

► Trillion sensors: processed data for upload►Maintenance free: energy efficient► IoT devices have to be

• small = material efficient• smart & secure = information processing • energy efficient = low power/standby

power free

IoT by energy harvesting: Battery-free - Is it possible?

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▌Energy Harvesting 300 µW: Solar cell with room light 100 µW: Vibration

▌Intermittent Sensing 10×10 sec-sensing a day

▌Distribution of Power 200 µW

• Sensing: 20 μW• RF: 80 μW• Microcontroller: 100 μW

200 µW

1

10

100

1000

10000

100000

1000000

0 100 200

Ultralow energy consumption processor

Energy harvesting supply power

Simple terminal control

Digital signal processing of sensor signals

Trend analysis

Recognition and

authentication

Processing Performance [MHz]

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[μW

]

(Source)：Renesas

Nikkei, Feb. 19, 2019

Spintronics processor

M. Natsui et al., ISSCC 2019.

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Breakdown of Power Consumption in a Data Center

32%

17%

44%

７%

Overall IT

Cooling system

Power supply

Power distribution

Portion of processor15%

Possible reduction

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MTJ/CMOS Nonvolatile VLSIs10

0.98

mm

1.44mm3.39mm

2.05

mm3.1m

m

3.5mm

1

Pow

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-99%

CMOS-based Spintronics0.01

1-97%

0.03

※in case of used for full text search system ※ in case of implementation to a typical application

x 11.7x ≦

129

11.5

164x 1

2x ≦1

321 164

x 1x ≦1

1001 164

(area)(power)(delay)

1-97%

0.03

※in case of typical cash operation

Non-volatile VLSIs for search engine for big data

Non-volatile field programmable gate array (FPGA)

Non-volatile cash memoryembedded in high speed CPU

NV-TCAM NV-FPGA STT-MRAM NV-MPU

4.79mm

4.79

mm

1-98%

0.02

x 1x ≦1

801 164

Non-volatile microcontroller forbattery-driven sensor device

※in case of use in a wireless sensor device

Pow

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onsu

mpt

ion

Pow

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mpt

ion

Pow

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CMOS-based Spintronics

(area)(power)(delay)

CMOS-based Spintronics

(area)(power)(delay)

CMOS-based Spintronics

(area)(power)(delay)

2013 Symposium. On VLSI Circuits 2013 IEICE Electronics Express 2014 IEEE ISSCC2012 Symposium. On VLSI Circuits

Prototype on 300 mm by Tohoku University

Autonomous Driving 11

https://dzone.com/articles/nvidia-introduces-computer-for-level-5-autonomous

Associative processor includes 12 core unit processor.

Process 90nm-CMOS/70nm-MTJ

Core Size 0.3mm x 0.9mmFrequency 20 MHzSupply Voltage 0.9 VAverage OperationPower

600 μW(30μW/MHz)

Throughput (cycles/vector) 16

AI Processor with CMOS/MTJ (Spintronics Device) Hybrid Technology

Y. Ma et al. Jpn. J. Appl. Phys. 55 04EF15 (2016).

Tensor Processing Unit（TPU）＠Google Process: 28 nm CMOS Frequency: 700 MHz Operation Power: 28～40W

(40～57mW/MHz)

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DRAM: dense

SRAM: fast

Current Working Memories

Both are volatile

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http://archive.doobybrain.com/2013/09/03/office-building-lights-night/

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Nonvolatile memories 15

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https://edition.cnn.com/2012/03/31/world/asia/earth-hour-preview/index.html

S. Ikeda et al., Nature Mat. 9, 721 (2010)

Key high performance nonvolatile memory element by spintronics:Perpendicular MgO-CoFeB Magnetic Tunnel Junction

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Interface!

Magnetic Tunnel Junction- bulk versus interface -

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CoFeB (interface)FePt (bulk)

Materials Efficiency (Cost of material)

10 :1

Recycling at the level of manufacturing tool: efficiency

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http://www.tel.co.jp/news/2014/1201_001.htm

300 mm wafer

~3%

Target

MTJ Product

97% left in the chamber

MTJ Material

5G, AI, Big Data, and IoT

Cache Memory

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