Andreas Mai

SiGe BiCMOS and Photonic technologies for high frequency and communication applications

Department Head Technology

Outline

• Introduction & Motivation

• SiGe HBT device developments for high RF performance

Optimization towards 700 GHz fMAX

• Electronic-Photonic-Integrated-Circuit (EPIC) SiGe-BiCMOS

Integrated components, transmitter & receiver circuits

• Summary

2

THz SiGe HBT and BiCMOS

Motivation

• High-speed SiGe HBTs used today for:

Automotive radar @ 24 GHz, 77 GHz and 120 GHz for transportation

High data rate optical and wireless links …

• Cut-off frequencies (fT, fmax) typically 3-10X larger than operating frequency

Larger design margins, lower noise, higher gain, better linearity

Lower power consumption

4

Motivation (cont)

• Further enhanced RF performance needed for potential new applications:

Back-haul for 5G mobile comm. (optical or wireless)

Short-range wireless links for high data rates

mm and sub-mm wave imaging and sensing in medicine, industry, and science

High-resolution sensors for robotics

• SiGe BiCMOS targets frequencies and data rates which are out of reach for state-of-the-art CMOS

5

European Projects on SiGe HBTs

• Enhancement of HBT performance and exploration of new application areas addressed

• DOTFIVE (2008-2011)Demonstration of HBTs with 500 GHz fMAX

• DOTSEVEN (2012-2016)Demonstration of HBTs with 700 GHz fMAX

• TARANTO (started 2017)BiCMOS platforms with 600 GHz fMAX targeting:

• Advanced automotive radar systems

• Infrastructure for 5G wireless and 400 Gb/s optical links

6

HBT Optimization & Process Modifications

7

Starting Point SG13G2 Final Status (D7)

Narrower Silicide Blocking Spacers

External Base Formation

Reduced Width of Emitter & Emitter-Base Spacer

SiGe Base Profile & Adjacent Low-Doped Emitter & Collector Region

Ni Silicide

Millisecond Flash Annealing & Low-Temperature Backend

Scaled Emitter-Poly Width & Collector Window

[Heinemann, IEDM 2016]

• Starting point: IHP’s 130nm BiCMOS “SG13G2”Highly-doped collector isolated by STIElevated extrinsic base

• Exploration of HBT performance limits irrespective of CMOS process constraints

BCTM ‘09

IEDM ‘16

IEDM ‘12

Enhancement of fT and fMAX

• Results of the DOT5 and DOT7 projects compared to IHPs 1st generation 130nm BiCMOS

8

200 300 400 500

100

200

300

400

500

600

700

800

IBM

STM

NXP

Tower/Jazz

IMEC

Infineon

IHP

f max

in G

Hz

fT in (GHz)

200 300 400 500

100

200

300

400

500

600

700

800

IBM

STM

NXP

Tower/Jazz

IMEC

Infineon

IHP

f max

in G

Hz

fT in (GHz)

200 300 400 500

100

200

300

400

500

600

700

800

IBM

STM

NXP

Tower/Jazz

IMEC

Infineon

IHP

f max

in G

Hz

fT in (GHz)

SiGe-HBT & BiCMOS performance evolution

200 300 400 500

100

200

300

400

500

600

700

800

IBM

STM

NXP

Tower/Jazz

IMEC

Infineon

IHP

f max

in G

Hz

fT in (GHz)

pre-„Dot5“2004…2009

within „Dot5“2009..2012

post „Dot5“2012…today

BCTM 2015

BCTM 2015

IEDM 2016

• Successfully finished Simultaneously fT > 400 GHz and

fmax ≈ 700 GHz for discrete HBTachieved

• Advanced HBT module (~0.5 THz) integrated into 0.13µm BiCMOS process of IFX

Demonstrator:

240 GHz RF chip-set + package(EuMW ‚16)

240 GHz radar transceiver + package + circular polarization (EuMC ’15)

550 GHz full Si CT scanner (IRMMW-THz ‘16)

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122GHz Radar as SiP and SoC (“SG13G2” == 0.5 THz – SiGe-BiCMOS)

System Requirements

Frequency: 122-123 GHz ISM

Pout: 0 dBm

GT = GR: 10 dBi

NF: 12 dB

BW: 1 GHz

SiP SoC

Modulation: CW/FMCW

Distance: up to 5 meters

On-chip integrated antennaby LBE process

10

Photonic-SiGe-BiCMOS (EPIC)

Silicon photonic transceivers

12

Data centerMetroTRANCEIVERTransmitter

Receiver

Fiber-uplink

Fiber-downlink

Major application areas for SiPh tranceivers

LASER MODULATORDRIVER

PD AMPLIFIER

• Different market segments of optical/photonic area (telecom, automotive …)

• Requirements for continuous growth in bandwidth and IP traffic in optical networks, Long Haul and Metro applications

• Goal: Join basic components of e/o Transceiver (modulator, driver, amplifier, photo-detector,..)

13

Transceiver is a multi-chip assembly

Hybrid /Co-packaging

G. Denoyer et al.; JLT 2015

Monolithic FEOL /CMOS Photonics

JS Orcutt et al.; OFC 2016

Monolithic FEOL /Photonic BiCMOS

IHP work

FEOL = Front End of Line

Major silicon ePIC approaches/technologies (select.)

14

• Photonic SOI CMOS• Zero-change Photonic CMOS• …. • Joint: CMOS + SiGe HBT + PIC

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SiGe HBTs0.25µm

RF-CMOS5 ML / MIM

170GHz fT 200GHz fmax 1.9V BVCEO

SG25H4_ePIC

Ge-PDs (high bandwidth, resp.) MZI modulator “130nm node” passives

State-of-the-art Si-photonics

40+Gb/s Strict modularity of photonic integration

Re-use of parent BiCMOSdevices (models)

No BiCMOS yield degradation

Re-use of DigLib

SG25H4 BiCMOSbaseline

Photonic BiCMOS 1st generation development goals

Central for EPIC– process integration

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• Shared wafer• Mixed Substrate:

• Localized SOI areas for optical structure• Bulk like substrate for BiCMOS structures

• Common backend• Modulized process flow

Green: ActiveRed: Waveguide

: STIGrey: local SOI

PIC- and EPIC-technology at IHP

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1. Mature 0.25µm-BiCMOS Technology available (SG25H4)

2. Development of PIC-process(Photonic Integrated Circuit) basedon established 0.25µm-BiCMOS Technology (SG25_PIC)

3. Integration of PIC in BiCMOS EPIC (Electronic Photonic Integrated Circuit) (SG25H_EPIC)

• More than 30 Masks

• More than 700 process steps> 20 Layer > 10 Layer

PIC

EPIC

EPIC Transmitters

Silicon cross section structuring

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• 3 etching depths available: 220nm, 120nm, 70nm• Vertical structuring is limited• Freedom in horizontal structuring

• Dopings: p, n, p+, n+

wire waveguide

rib waveguide

Grating structures

Transmitters differ in phase shifter structure

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Dopedwaveguide

• Depletion type

• Injection type

TM2

TM1

MET3

MET2

MET1

BOX

0 1 2 3 4 5 6 7 82

3

4

V-P

i*L

[V

*cm

]

Voltage [V]

0 1 2 3 4 5 6 7 810

11

12

alp

ha

[d

B/c

m]

Voltage [V]

Mach-Zehnder modulator – segmentation

21

Traveling wave electrode:

• Significant RF loss on the line

• Limited bandwidth and extinction ratio

• Velocity mismatch between optical and electrical waves

Segmented MZM:

• Modulator divided into lumped segments

• Constant voltage along the phase shifter → high ER

• Bandwidth expected to be less dependent on length → longer phase shifters can be driven effectively with low driving voltage

inte

grat

ion

Single MZM with linear driver

22

9.8 mm

1.3

mm

• 6 mm phase shifter divided into 16 segments

• Total fiber-to-fiber loss equal to 17 dB (5 dB fromthe phase shifter)

500 nm

1000 nm

16

40

nm

D. Petousi et al, Monolithic Photonic BiCMOS Sub-SystemComprising Broadband Linear Driver and Modulator Showing 13 dB ER at 28 Gb/s, CLEO, 2016

ER=13.37 dB

• Power dissipation equal to2W or 71 pJ/bit at 28 Gb/s

• EO bandwidth 18GHz

28 Gb /s

ER=13.37 dB

measurement simulation

MZM + driver with integrated DAC

Concept:.

9 mm

2 m

m

D. Petousi et al. “High-Speed Monolithically Integrated Silicon Photonic Transmitters in 0.25 μm BiCMOS Platform”. ECOC 2016.

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…

light in light out

bit 0

driver w/DAC + MZM

limitingamplifiers

……

bit 1

bit N-1

Utilizing the segmentation of the modulator

Integrated DAC resolution is limited due to layout and area constraints.

With digital inputs, the driver is implemented as switching amplifier reducing power dissipation

NO EXTERNAL DAC.

Integrated Germanium photo diode

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Waveguide stub Metal1 contact

Germanium photodiodebuilding block

S. Lischke et al. Optics Express 23 (21), 2015Jeong-Min Lee et al, Photodetection Frequency Response Characterization for High-Speed Ge-PDon Si with an Equivalent Circuit, WA2-78, OECC 2016

Performance f3dB>65GHz@-2V R>0.9A/W Idark<100nA@-1V

M2J_BW_0V () _

file: EFA602_M2J_BW0V valid range: 0.41 ... 84.28 valid: 100.0%

wafer: EFA602-[06] mean ± 1s (lot): 42.34 ± 2.10

dice: 61 mean ± 1s (wafer): 42.34 ± 2.10

invalid

invalid

>

<

48.00

47.00

46.00

45.00

44.00

43.00

42.00

41.00

40.00

39.00

38.00

37.00

1

1

2

6

10

6

10

9

15

1

11

10

9

8

7

6

5

4

3

2

1

1 2 3 4 5 6 7

class width = 1.00

M2J_BW_0V () _

file: EFA602_M2J_BW0V valid range: 0.41 ... 84.28 valid: 100.0%

wafer: EFA602-[06] mean ± 1s (lot): 42.34 ± 2.10

dice: 61 mean ± 1s (wafer): 42.34 ± 2.10

invalid

invalid

>

<

48.00

47.00

46.00

45.00

44.00

43.00

42.00

41.00

40.00

39.00

38.00

37.00

1

1

2

6

10

6

10

9

15

1

11

10

9

8

7

6

5

4

3

2

1

1 2 3 4 5 6 7

class width = 1.00

Vbias=0V, =1550nmmean=42GHz (=2GHz)

GePD: Benchmark – Responsivity, e/o BW and dark current

25

-1 V -2 V >-2 V

Fully integrated Ge PD in BiCMOS exceed performance level of discrete PD

Enabler for high efficient Rx EPIC designs

EPIC Circuit Examples

27

M. Kroh et al, Monolithic Photonic-Electronic Linear Direct Detection Receiver for 56Gbps OOK, ECOC 2016

Extended BW (36GHz)

IHP Rx

Reference PD

28Gbd PAM4

Up to 56Gbps NRZ OOK

Recent results – linear SP receiver

32 Gbps 40 Gbps

48 Gbps 56 Gbps

Photonic BiCMOS evolution

Demonstrators: monolithically integrated O/E RECEIVERS

25 Gbps

2014

40 Gbps

2015

56 GbpsGrating Coupler

Ge PD

TIA

2016 [ECOC2016 &ESSCIRC2016]

[Knoll et al., OFC 2014]

[Awny et al., MWCL 2015]

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Photonic BiCMOS evolution

Demonstrators: monolithically integrated E/O MODULATORS

10 Gbps

2013

32 Gbps

2016

[Zimmermann et al., ECOC 2013]

[Petousi et al., PTL 2016]

HELIOS

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Summary

• Record values of fT=505 GHz, fMAX=720 GHz and tRO=1.34 psdemonstrated in an experimental SiGe HBT process

Room for further improvements by lateral scaling

• EPIC technology developments show potential for beyond 100Gbit/s optical interfaces

• Ongoing challenging task of integrating these HBTs and Photonic modules in a BiCMOS platform

30

Acknowledgment

• IHP colleagues H. Rücker, B. Heinemann, D. Kissinger, H. Ng., L. Zimmermann, D. Knoll, S. Lischke, D. Petousi & M. Kroh

• IHP clean room staff

• Project partners and funding sources EU (H2020) & BMBF

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Thank you for your attention!

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