on wafer small signal characterization beyond 100 ghz for...

On wafer small signal characterization beyond 100 GHz for compact model assessment

Sebastien Fregonese#1, Marina Deng#1, Marco Cabbia#1, Chandan Yadav#1, Soumya Ranjan Panda #1&2, Thomas Zimmer#1

#1Université Bordeaux / CNRS, laboratoire IMS, FRANCE

#2IIT Madras, India

#1 Sebastien.Fregonese@ims-bordeaux.fr

WS-01 Recent advances in SiGe BiCMOS: technologies, modelling & circuits for 5G, radar & imaging

http://tima.univ-grenoble-alpes.fr/taranto/

- 2 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Motivation

• EM simulation vs Measurement up to 500 GHz

• HBT measurement up to 500 GHz

• Conclusion and Outlooks

Outline

- 3 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

Motivation

Accurate S-parametermeasurements above 110 GHz =

big challenge

RF circuit/system design

Accurate compact modelsRelies on

Extraction of specific parametersValidation

Transistor HF Characterization Challenges

- 4 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Calibration & De-embedding Issues

Motivation

Standard procedure (2-step calibration)

Reference plane after calibration

Vectorial Network Analyzer (VNA)

Port 1 Port 2

mmW head mmW headRF probes

Impedance Standard SubstrateFrom Cascade Microtech

1Off-wafer

calibration on ISS

- 5 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Calibration & De-embedding Issues

Motivation

Different electrostatic environment

calibration range of validity ?

Reference planeafter calibration

Ref. plane afterde-embedding(DUT terminals)

2On-wafer

de-embedding

- 6 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Calibration & De-embedding Issues

Motivation

Different electrostatic environment

calibration range of validity ?

Reference planeafter calibration

Ref. plane afterde-embedding(DUT terminals)

Same electrostatic environment

calibration range of validity ?

2On-wafer

de-embedding

1On-wafer TRL

calibration

- 7 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• S parameters measurement above 110 GHz requires to answer the following questions:

• Which calibration & de-embedding method should I use ?

• Do I really measure my DUT ? Impact of adjacent structures

Impact of probes

=> Need for reproducing measurement results with EM simulation tools

Motivation

- 8 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

EM simulation vs Measurement up to 500 GHz

SOLT on ISS De-embedding

Extraction of SOLT

parameters using ISS TRL

Simulation of :ThruReflect (open, Short) LinesLoad

Simulation of :DUTPad openPad short Intrinsic DUT

ISS SOLT

- 9 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Characterisation of the ISS calibration kit for SOLT

EM simulation vs Measurement up to 500 GHz

Interferometry image of the through from the ISS (GGB-CS15)

Data sheet of

CS15 delivered by Pico-probe GGB

industries used for 50-125 µm probe

pitch

EM simulation for 50 µm probe pitch (extracted from TRL at 60 GHz and 250

GHz)

Open 3.25fF 3.2-3.4fF

Short 2pH 1.5 pH-2.5pH

Load 1.5fF 1.4-2.2fF

Through 1.13ps 1.10ps

- 10 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Silicon test structures:

EM simulation vs Measurement up to 500 GHz

M1 Cu

M2 Cu

M3 Cu

M4 Cu

M6 Cu

M7 Alu

M5 Cu

Two thickcopper + onealuminiumlayer

Four thincopper layers

Infineon’s B11HFC BEOL

Reflect pad open

Line of 160µm

Thru of 50µm

Pad short

Transistor open Meander line.

Load

The probe pitch is 50 µm

- 11 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

EM simulation vs Measurement up to 500 GHz

SOLT on ISS De-embedding

Extraction of SOLT

parameters using ISS TRL

Simulation of :ThruReflect (open, Short) LinesLoad

Simulation of :DUTPad openPad short Intrinsic DUT

ISS SOLT

- 12 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Pad short & Pad open

EM simulation vs Measurement up to 500 GHz

-4

-3

-2

-1

0

1

2

3

4

0 100 200 300 400 500

mag

(Sii)

(d

B)

freq (GHz)

Measurement with SOLT cal.

EM sim. with SOLT cal.

0

30

60

90

120

150

180

0 100 200 300 400 500

ph

ase(

S ii)

(°)

freq (GHz)

Measurement with SOLT cal.

EM sim. with SOLT cal.

PAD SHORT after SOLT calibration

Measurement vs Simulation

-4

-3

-2

-1

0

1

2

3

4

0 100 200 300 400 500

mag

(Sii)

(d

B)

freq (GHz)

Measurement with SOLT cal.

EM sim. with SOLT cal.

-120

-90

-60

-30

0

30

60

90

120

150

180

0 100 200 300 400 500p

has

e(S i

i) (°

)freq (GHz)

Measurement with SOLT cal.

EM sim. with SOLT cal.

PAD OPEN after SOLT calibration

Measurement vs Simulation

Ref. plane

Ref. plane

- 13 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

EM simulation vs Measurement up to 500 GHz

SOLT on ISS De-embedding

Extraction of SOLT

parameters using ISS TRL

Simulation of :ThruReflect (open, Short) LinesLoad

Simulation of :DUTPad openPad short Intrinsic DUT

ISS SOLT

- 14 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Calibration and de-embedding : transistor open

EM simulation vs Measurement up to 500 GHz

-3

-2

-1

0

1

0 100 200 300 400 500

mag

(S2

2)

(dB

)

freq (GHz)

Measurement Simulation with SOLT cal.

EM intrinsic

SOLT ISS

-180

-120

-60

0

0 100 200 300 400 500

ph

ase(

S 22)

(°)

freq (GHz)

Measurement Simulation

EM intrinsic

SOLT ISS

Ref. plane

- 15 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

EM simulation vs Measurement up to 500 GHz

TRL on wafer with Zc correction

Simulation of :ThruReflect LinesLoad

Simulation of :DUTPad openPad short

Intrinsic DUT

On wafer TRL

simulation

- 16 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Calibration and de-embedding : transistor open

EM simulation vs Measurement up to 500 GHz

-3

-2

-1

0

1

0 100 200 300 400 500

mag

(S2

2)

(dB

)

freq (GHz)

Measurement Simulation with SOLT cal.

EM intrinsic

SOLT ISS

-3

-2

-1

0

1

0 100 200 300 400 500

mag

(S2

2)

(dB

)

freq (GHz)

Measurement Simulation

EM intrinsic

TRL on wafer

-180

-120

-60

0

0 100 200 300 400 500

ph

ase(

S 22)

(°)

freq (GHz)

Measurement Simulation

EM intrinsic

SOLT ISS

-180

-120

-60

0

0 100 200 300 400 500

ph

ase(

S 22)

(°)

freq (GHz)

Measurement Simulation

EM intrinsic

TRL on wafer

Ref. plane

- 17 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Calibration and de-embedding : meander line

EM simulation vs Measurement up to 500 GHz

-5

-4

-3

-2

-1

0

1

2

3

0 100 200 300 400 500m

ag(S

ij) (

dB

)

freq (GHz)

Measurement Simulation

EM intrinsic

SOLT ISS

-5

-4

-3

-2

-1

0

1

2

3

0 100 200 300 400 500

mag

(Sij)

(d

B)

freq (GHz)

Measurement Simulation

EM intrinsic

-200

-150

-100

-50

0

50

100

150

200

0 100 200 300 400 500

ph

ase(

S ij)

(°)

freq (GHz)

Measurement Simulation

EM intrinsic

-200

-150

-100

-50

0

50

100

150

200

0 100 200 300 400 500

ph

ase(

S ij)

[°]

freq (GHz)

Measurement Simulation

EM intrinsic

SOLT ISS

Ref. plane

- 18 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Limitation of the SOLT ISS parameters:• Frequency dependence

• Probe dependence

• Substrate to probe coupling• Probe dependence

• Cal-kit material and wafer material

• Limitation of the de-embedding

=> TRL on ISS is used to identify these 3 limitations

EM simulation vs Measurement up to 500 GHz

- 19 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• SOLT on ISS and TRL ISS with pad-open pad-short de-embedding and on wafer TRL versus intrinsic simulation

EM simulation vs Measurement up to 500 GHz

-4

-3

-2

-1

0

1

0 100 200 300 400 500

mag

(S2

2)

(dB

)

freq (GHz)

On wafer TRL ZCISS cal TRL and de-embeddingISS cal SOLT and de-embedding

intrinsic

-180

-150

-120

-90

-60

-30

0

0 100 200 300 400 500

ph

ase(

S 22)

(deg

)

freq (GHz)

On wafer TRL ZCISS cal TRL and de-embeddingISS cal SOLT and de-embedding

intrinsic

• ISS SOLT and TRL give similar results on the phase but deviate slightly from the intrinsic result from 50 GHz

Deviation is due to electrostatic environment and/or de-embedding procedureSOLT calibration itself and parameters cannot explain the deviation of the

phase

- 20 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Impact of adjacent structures:

EM simulation vs Measurement up to 500 GHz

EM simulation @ 500 GHz

Too dense layout !

- 21 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Impact of adjacent structures:

EM simulation vs Measurement up to 500 GHz

Ref. plane

With adjacent devices in Thru,

Refl., Line and DUT

-2

-1

0

0 100 200 300 400 500

mag

(S2

1)

(dB

)

Frequency (GHz)

Measurement + TRL cal.

EM sim. +TRL cal.

-2

-1

0

0 100 200 300 400 500

mag

(S21

) (d

B)

Frequency (GHz)

Measurement + TRL cal.

EM sim. with neighboring structures +TRL cal.

Adjacent structures modifies the result

- 22 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Impact of probe topology• On wafer calibration (STMicroelectronics B55 technology)

EM simulation vs Measurement up to 500 GHz

EM sim. setup

IEEE ICMTS 2018IEEE ICMTS 2018

220 GHz Picoprobe model

- 23 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• STMicroelectronics B55 technology• On wafer TRL + short-open de-embedding

• Improved test structures (Pads layout, more space between structures, …)

• Measurement vs HICUM compact model with substrate extension

Application to the HBT

-40

-30

-20

-10

0

10

20

30

0 100 200 300 400 500

Mag

(S)

[dB

]

freq [GHz]

HBT B550.09*4.8µm²VBE=0.85 VVCB=0 V

S21

S12

S11

S22

-180

-120

-60

0

60

120

180

0 100 200 300 400 500

Ph

ase(

S) [

°]

freq [GHz]

HBT B550.09*4.8µm²VBE=0.85 VVCB=0 V

S21

S12

S11

S22

Characterisation & modelling is uncertain above 350 GHz

HICUM Meas.

- 24 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• STMicroelectronics B55 technology

Application to the HBT

-10

0

10

20

30

40

50

0 100 200 300 400 500

H2

1[d

B]

freq [GHz]

HBT B55 AE=0.09*4.8µm²VCB=0V

VBE=0.85V

-10

-5

0

5

10

15

20

25

30

35

40

0 100 200 300 400 500U

[d

B]

freq [GHz]

HBT B55AE=0.09*4.8µm²VCB=0V

VBE=0.85V

HICUMMeasurement HICUM

Measurement

- 25 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• The simulation methodology has been proven to be able to accurately reproduce the impact of the measurement methodology and set-up

• ISS calibration (SOLT or TRL) with OS de-embedding is not accurate above 200 GHz

• Adjacent structure have an impact on measurement results => requires optimized layout

• HBT: On wafer TRL and especially SO de-embedding => to be verified above 350 GHz

Conclusion

The research leading to these results has received funding from the European Commission'sECSEL Joint Undertaking under grant agreement n° 737454 - project TARANTO - and therespective Public Authorities of France, Austria, Germany, Greece, Italy and Belgium.

Thank you

- 26 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

- 27 -WS-01 - Recent advances in SiGe BiCMOS: technologies, modelling and circuits for 5G, radar and imaging

• Our recent references:

• S. Fregonese et al., Comparison of on-wafer TRL calibration to ISS SOLT calibration with open-short de-embedding up to 500 GHz, IEEE Trans. Thz Sci., 2019

• S. Fregonese et al., On-wafer characterization of silicon transistors up to 500 GHz and analysis of measurement discontinuities between the frequency bands, , IEEE Trans. on MTT 2018

• M. Deng, “RF Characterization of 28 nm FD-SOI Transistors Up To 220 GHz”, EUROSOI ULIS, 2019

• C. Yadav et al., On the Variation in Short-Open De-embedded S-parameter Measurement of SiGe HBT upto 500 GHz, 2019 GeMiC

• C. Yadav et al., Analysis of Test Structure Design Induced Variation in on Si On-wafer TRL Calibration in sub-THz, 2019, ICMTS

References