bonded photonic structure incorporated into a chip · acknowledgements selete hisatsune watanabe,...

Keishi Ohashi*1,*2

Masafumi Nakada*1,*2

Takahiro Nakamura*2

*1MIRAI-Selete*2NEC Corporation

September 20-24, 2009, Vienna, Austria

ECOC 2009 WS3“Optics in Computing – How much is enough?”

Bonded Bonded PPhotonic hotonic SStructure tructure IIncorporated into a ncorporated into a CChiphip

Acknowledgements

Selete Hisatsune Watanabe, Tohru Mogami, Takanori Shimizu, Jun Ushida, Masao Kinoshita, Nobuo Suzuki, Toshihide Ueno, Kenichi Nishi

NTT Toshifumi Watanabe, Yasushi Tsuchizawa, Kouji Yamada, Seiichi Itabashi

NEC Junich Fujikata, Tsutomu Ishi, Koichi Nose, Toshio Baba, Kikuo Makita, Shigeru Nakamura, Kazuhiko Kurata, Shigeyuki Yanagimachi, Tao Chu, Hirohito Yamada

This work was partly supported by NEDO (New Energy and Industrial Technology Development Organization).

Outline1. Optical Interconnection2. Interconnect Era3. Nanophotonics4. Si Photonics for Photonic NW:

or vice versa5. Summary

Outline

1. Optical Interconnection2. Interconnect Era

3. Nanophotonics

4. Si Photonics for Optical NW: or vice versa

5. Summary

Larger Market

Smaller Distance

Optical Interconnects in Electronics

Penetration of high data capacity optical communication from long-haul to short-distance interconnect.

Between Computers

Between Boards

Between Chips

m

cm

mm

kmTelecommunication

On-Chip Interconnect

Short Electrical Signal lines

Optical Fibers

Photoelectric Devices

LSI

• 10Gbps x 4 Ch Transceiver

• 14mm x14mm

Courtesy of K. Kurata

On-Bord Optical Interconnection

Courtesy of K. Kurata

Optical Interconnection between CPU & Memory in HPC

• Small size of 5 mm2, 20 Gbps x 12ch OE/EO converters with a water-cooling module

• ~1000-channel OE converter is attached around CPU

• High reliability VCSEL (λ = 1.07 μm) is developedOptical connectorWater-cooling module is attached here

Replacement of Electrical Interconnect to Optical One

External EO/OE Module

Optical Interconnect Using Photonic SiP

LSI On-chip Optical Interconnect

LSI

LSI

3D LSI

Optical Layer

EO/OEEO/OEOptical Connector

Optical ConnectorEO/OEEO/OE

Waveguide

Fiber

<5 mm

5-10 mm

50-200 mmOptical Interconnect

Electrical Interconnect

Courtesy of Y. Hashimoto & S. Yanagimachi

Cross Point for On Board Interconnection

Optics gives lower power consumption for back plane (~1 m)

Optical

Electrical

75 cm @6 Gbps

H. Cho, et al., J. Lightwave Technol. 2004.

Outline

1. Optical Interconnection

2. Interconnect Era3. Nanophotonics


5. Summary

Bottleneck of Global Interconnects

In 2012, a 1-mm-long interconnect’s latency will be 100 times larger, and its binary switching energy will be 30 times larger,than a corresponding transistor. J. D. Meindl, Computing in Sci. & Engrng, 2003.

3D-Integration

Shorter Length by Vertical Connection

Optical Signal SiON

waveguide

Nano photodiode

Optical Interconnect

Different Physics for Lateral Connection

Power Consumption in LSI

Interconnect

Gate

150 130 100 90 80 70 65 45 32 20 [nm]

Dynamic power is larger than heat removal capacityD

ynam

ic P

ower

Global (data)

Global (clock)

Local (data)

Local (clock)

N. Magen et al, SLIP 04

Diffusion

ITRS maximum heat removal capability



M. Mizuno et al., ISSCC 2001

20 mm-interconnects with repeaters

Cu/Low-k, リピーター

電子回路電子回路Circuit

Cu/Low-k, RepeatersCircuit





Bill Dally, ISSCC 2005

High Power Consumption by Interconnect



From Electrical To Optical





Advantages: No repeaters, Small delay, Small jitter, Immune to EMI, High data capacity, …

0.1

1

10

100

1000

1 10 100

Electric Interconnecthp65(2007)


(2013)

Wiring Length (mm)

Pow

er D

elay

Pro

duct

(pJ

)

Short Range Optical Interconnection

1pJ/1bit1W/1Tbps

hp22(2016)

Target(2015)

(2009)

Reduce overhead by introducing micro EO and OE devices

@10 Gbps

Current

Outline


2. Interconnect Era

3. Nanophotonics4. Si Photonics for Optical NW: or vice versa

5. Summary

De Broglie wavelength of electron

Wavelength of light(visible - near IR)

~0.1 nm~1000 nm

Photonic Crystal

Near-Field

Surface Plasmons

1/2 ~ 1/5Si Photonics

1/5 ~ 1/100

Size Comparison: Light vs. Electron

(100 V)

+metamaterialmaterials

Contour map of light power (in Z direction)

Coupling length ~10μm

Contour map of electric field

Input light (TM polarized)

Si nano-photodiode

Ag electrode embedded in Si)

SiON waveguide1.1μm

Plasmon Antenna Embedded in Si

J. Fujikata, et al.,, APEX, 1. 022001, 2008.

SiON Waveguide

Optical Interconnect Chip(front side for bonding)

LSI chip

Optical Signal SiON

waveguide

Si nano-photodiode

Bonding Optical Interconnect on LSI

Optical Interconnect Chip(front side for bonding)

T. Shimizu, et al., ICEP 2008, 12B3-3.

Si nano-photodiodeSi

Si

Cu AuSn10 mm

Bonded Structure (Cross-Section)

T. Shimizu, et al., ICEP 2008, 12B3-3.

LSI Chip Si


Chip

Si Nano-PhotodiodeSiON Core

Si Cu-via

SiO2

Flip-Chip Bonding with LSI Chip

Flip-Chip Bonding

AuSn Bump

Face-to-face bonding gives short vias

Large tolerance for alignment (±5 μm)

15 μm

Large tolerance for alignment compared with optical via

>10 GHz

Pulses from Light Source (5GHz)

50 ps100 mV

5 GHz5 GHz

Operation of LSI Using Optical Clock

Output signal from electronic circuit

5-GHz optical pulses triggered the LSI circuits

LSI chip

Optical Interconnect Chip

1mm

100ps

J. Fujikata, et al., APEX, 1. 022001, 2008.

Outline


2. Interconnect Era

3. Nanophotonics

4. Si Photonics for Photonic NW: or vice versa

5. Summary

50 mm Port 4

Port 3Port 2

Port 1

50 mm Port 4

Port 3Port 2

Port 1

50 mm Port 4

Port 3Port 2

Port 1

50 mm Port 4

Port 3Port 2

Port 1

50 μm Port 4

Port 3Port 2

Port 1

Input light Output light

WorldWorld’’s smallest 1 x 4 Optical Switchs smallest 1 x 4 Optical Switch Chip (Chip (190190××7575 μμmm22))

Optical Switch

1×4 Optical SW Module

Courtesy of T. Chu

One-Chip Colorless MUX/DEMUX Using Si Photonic Circuit

Moduleport 1

port 2

port 3

port 4

port 5

port 6

S. Nakamura, et al., ECOC2008, Tu.4.C.6

Using Si waveguides, an AWG and switches were integrated into a chip. Low-power and quick reconfiguration of optical paths within a 2-mm device was demonstrated.

500 μm

Circuit

WDM for Interconnection


More than 50% of production cost for state-of-the-art LSIs comes from interconnect. … T. Shibata (Toshiba) 2008.

On-chip optical WDM (Wavelength Division Multiplexing )

Data transfer rate increase (～one order)Reduction of pin #

On-plain crossing by optical waveguidesLess interconnection layersLess crosstalk

memory array

SDRAM with opt. I/F

optical clock

multiple wavelength light sources

clock bank1bank2bank3bank4

serial to parallel conversion

clock synchronization

writeread

swsw

sw

sw

div

div

Multi-bank memory I/F

IP’s via NoC

MUX

MUX DEMUX

DEMUX

clock

bank1bank2

bank3

bank4

modmod

modmod

modmod

modmod

Optical Ring Bus Connecting Chip & Memories

3-D Integration + Optical Interconnect

3-D Integrated LSI

Optical Layer

Input WDM Signal

Output WDM Signal

Integrated Optical Layer / LSI Chip

(Optical Clocking)

On-Chip WDM

Adjacent Chip

WDM Signal

(Data + Clock)

Functional Block (Core)

On-Chip Optical Network

Waveguide

Micro-node

• Mod/SW• AWG/Filter

• PD

SiON Waveguide for On-chip WDMBranching Structure

Si Nano Photodiode

WDM Circuit with Si Nano Photodiode

Si nano PD(photo-diode)

10 GHz signal from WDM signal was extracted by the integrated demultiplexter and Si nano photodiode.Crosstalk noise; less than -10dB.

Extracted 10 GHz signal

Wavelength (nm)

Inte

nsity

(10

dB/d

iv)

Spectrum of input optical signal (3 wavelengths)

SiON demultiplexer(3x4mm2)

10um

Integrated WDM Function with Si Nano PD

Outline


2. Interconnect Era

3. Nanophotonics


5. Summary

• We proposed an approach for on-chip optical interconnect suitable for 3-D integration.

• Flip-chip bonding of an optical interconnect chip with a LSI reduces the electrical path enough to obtain high speed response of >10 GHz.

Summary

bonded photonic structure incorporated into a chip · acknowledgements selete hisatsune watanabe,...

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