Radiation testing on opto-electronic devices at SCK·CEN

4th RD50 WorkshopCERN, Genève - CH, 5-7 May 2004

Francis Berghmans

Benoît Brichard, Alberto Fernandez Fernandez, Ivan Genchev, Andrei Goussarov, Marco Van Uffelen

• Short presentation of SCK·CEN• Irradiation facilities• Some typical results on opto-

electronic devices• Future work

SCK•CEN

360 ha

Laboratories :Boeretang 200B-2400 MolBelgium

Registered Office :Av. Herrmann Debroux 40-42B-1160 BrusselsBelgium

Studiecentrum voor KernenergieCentre d’étude de L’Energie Nucléaire

SCK•CEN is a Research Institute

• Institute of Public UtilityMinistry of Economic Affairs

Secretary of State for Energy• 600 Employees

200 scientists• Annual Turnover 74•106 €

50 % Governmental subsidy -50 % Contracts• Core activities

Nuclear Safety and Radiation ProtectionIndustrial Applications of RadiationBack-end of the Nuclear Fuel CycleNon-energetic applications of nuclear energy

increasingly relevant to society – medicineSustained development and non-technical aspects

social and economical factors, ethics, liability

Our main R&D environment is ITER as supported by the

European Fusion Programme

• Environmental constraints

100 MGy (10 Grad)10 kGy·h-1 (1 Mrad·h-1)Occasional neutrons150 °C

• Instrumentation systems

CommunicationRemote-handling & sensorsFusion plasma diagnostics

We’ve been experimenting on a broad range of

devices/materials/technologies

• Laser diodes (AlGaAs VCSELs)• Photodiodes (Si, InGaAs)• A wealth of optical fibres

COTS and custom• Fibre Bragg Gratings• WDM Couplers• Liquid crystals• Fibre sensors• Electronics• Motors• Polymers• Cables (polymers, mineral insulated, …)• Connectors & feedthroughs• …

We exploit SCK·CEN’s irradiation infrastructure

Brigitte(60Co - fuel)

RITA(60Co)

Geuse II(fuel)

LNC(60Co)

Dose-ratemax.

Dose-ratemin.

Vol. (mm2)

Vol. Temp.

VUBCyclotron

1.4 krad•s-1

140 rad•s-1

300 rad•s-1

30 mrad•s-1 2 rad•s-1

15 rad•s-1 140 mrad•s-1

900 x 220900x80

600 x 380 400 x 380

50 - 200 °C RT - 100 °C RT RT stabilised

BR1

BR2

Hot cell

0.3 mrad•s-1

CERN irradiates opto-electronics for CMS in RITA

Vacuum System Module for RITA and GEUSE II is designed

• Vacuum: 10-5 mbar• Height: 600 mm• Diameter: 200 mm• Temperature: 120°C• Organic material

mass up to 1 kg

BR1 is a versatile neutron-gamma irrradiation tool

Reactor core Graphite Concrete

PneumaticSamplechanger

Neutronography

Irradiation channels

Thermal column spherical cavity

Reactor core Graphite Concrete

PneumaticSamplechanger

Neutronography

Irradiation channels

Thermal column spherical cavity

© SCK•CENBR1

© SCK•CENBR1 sphere

© SCK•CENBR1 scheme

• Natural U, graphite-moderated, air-cooled research reactor

reactor physics experiments as neutron reference sourcecalibration of nuclear detectors

• CharacteristicsChannels

φ 80 mm, square 100 ×100 mm2

fast n > 2.86 108 n·cm-2·s-1

thermal n < 3.5 1011 n·cm-2·s-1

around 50 °C (control possible)Sphere

empty - φ 1000 mm1 cm U shield – φ 325 mmempty – thermal n < 7 108 n·cm-2·s-1

1 cm U shield – fast n 2.18 108 n·cm-2·s-1

BR2 is a high neutron flux material testing reactor

© SCK•CENBR2

© SCK•CENBR2 configuration

© SCK•CENBR2 scheme

• PWR type reactor (flux up to 1015 n·cm-2·s-1)

test of fuels and materialsproduction of radioisotopessilicon doping for electronics industry

• CharacteristicsCentral channels

φ 84 mmfast n – 2 1014 n·cm-2·s-1

thermal n – 4 1014 n·cm-2·s-1

(5 W·g-1 Al)Peripheral

φ 200 mmfast n – 3.5 1014 n·cm-2·s-1

thermal n – 1 1014 n·cm-2·s-1

(4 W·g-1 Al)

Aging, lifetime testing and temperature cycling studied in

CLARA (2 m³)

We can cover most radiation effects application fields

Gamma rays and Neutrons have different effects on VCSEL P-I curve

• Gamma IrradiationNo threshold current shiftExternal efficiency decrease

• Neutron IrradiationThreshold current shiftExternal efficiency decrease

0 2 4 6 8 10 12 14 16 180.0

0.2

0.4

0.6

0.8

1.0

Out

put P

ower

(mW

)

Forward Current If (mA)

Unirradiated 0.5 MGy 1.0 MGy 2.0 MGy 4.0 MGy 10 MGy

0 2 4 6 8 10 12 14 16 180.0

0.1

0.2

0.3

0.4

0.5

0.6

Out

put P

ower

(mW

)

Forward Current If (A)

Unirradiated 1.02E14 n/cm² 5.20E14 n/cm² 9.45E14 n/cm² 1.37E15 n/cm² 1.79E15 n/cm² 2.22E15 n/cm² 2.64E15 n/cm² 3.07E15 n/cm² 3.49E15 n/cm²

F. Berghmans et al., "Design and Characterization of a Radiation Tolerant Optical Transmitter using Discrete COTS Bipolar Transistors and VCSELs", IEEE Transactions on Nuclear Science 49, pp. 1414-1420, 2002

Pre-irradiation with gamma accelerates degradation

COTS p-i-n photodiodes were monitored in-situ under radiation

• First 60Co gamma experiment6 Si-PD2 kGy/h (10% accur.), 2 MGy, 60°C ± 1.5°C

• Mixed neutron/gamma experimentpre-irradiated Si-PD (2 MGy)7·1015n/cm2, 20 kGy (background), 60°C ± 1.5°C

• Second 60Co gamma experiment8 Si-PD & 8 InGaAs-PD15 kGy/h (10% accur.), 10 MGy, 60°C ± 1.5°C

A typical result for a Siphotodiode after 2 MGy

Response PD 1 @ 850 nm

y = 0.4595xR2 = 0.9991

y = 0.4127xR2 = 0.9981

0E+00

1E-06

2E-06

3E-06

4E-06

5E-06

6E-06

7E-06

8E-06

9E-06

0E+00 5E-06 1E-05 2E-05 2E-05 3E-05

Incident power [W]

Phot

ocur

rent

[A]

beginendResponse PD1 (begin)Response PD1 (end)

4-5% after 2 MGy

M. Van Uffelen et al., "Reliability study of photodiodes for their potential use in future fusion reactor environments", SPIE Proceedings 5465, 2004, to be published

Neutron displacement damage is an issue

Response PD1 in BR1 @ 850 nm

y = 0.4489x + 2E-08R2 = 0.9988

y = 0.3649x + 9E-06R2 = 0.9983

-2E-06

0E+00

2E-06

4E-06

6E-06

8E-06

1E-05

1E-05

1E-05

0.0E+00 4.0E-06 8.0E-06 1.2E-05 1.6E-05

Incident power [W]

Phot

curr

ent [

A]

beginend

~ 10%

x 103

Total dose : Dγ = 20 kGyFluence : nth = 7·1015n/cm2

M. Van Uffelen et al., "Reliability study of photodiodes for their potential use in future fusion reactor environments", SPIE Proceedings 5465, 2004, to be published

InGaAs photodiodes show different dark current curves

after irradiation

Dark current PD 1 (after 10 MGy)

0E+00

1E-06

2E-06

3E-06

4E-06

5E-06

6E-06

7E-06

8E-06

0 5 10 15 20 25Reverse voltage [V]

Cur

rent

[A]

70°C60°C_begin60°C_end50°C40°C

Dark current PD 1 (before irradiation)

0.0E+00

5.0E-10

1.0E-09

1.5E-09

2.0E-09

2.5E-09

3.0E-09

0 5 10 15 20 25Reverse voltage [V]

Cur

rent

[A]

70°C

60°C

50°C

40°C

M. Van Uffelen et al., "Reliability study of photodiodes for their potential use in future fusion reactor environments", SPIE Proceedings 5465, 2004, to be published

InGaAs photodiode dark current increases monotonously ~ 103

InGaAs PD 1

0

100

200

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900

Elapsed time [hr]

Rel

ativ

e ra

diat

ion

indu

ced

dark

cur

rent

[%] -3V

-5V

-10V

-15V

-20V

Dose rate : dDγ /dt= 15 kGy/h

Packaging is an issue

Before irradiation After irradiation

Future work is needed and could benefit from interaction with RD50

• Effects are generally understood but phenomenologically treated

No thorough theoretical investigation on material radiation effects RD50Material effects, device structure effects and device performance need to be linkedModelling is essential for reliability assessment RD50

• Further experimental workGain statistical significanceQualification is essential but expensive and time consuming

• Our irradiation facilities are availableand can be adapted to your specific needs RD50