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To cite this document: Goiffon, Vincent and Magnan, Pierre and Saint-Pé, Olivier and

Bernard, Frédéric and Rolland, Guy Ionization versus displacement damage effects in

proton irradiated CMOS sensor manufactured in deep submicron process. (2008) In:

New Developments In Photodetection (NDIP), 15 June 2008 - 20 June 2008

(Aix-les-Bains, France). (Unpublished)

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Ionization versus displacement damage effects in

proton irradiated CMOS sensors manufactured in

deep submicron process

V. Goiffon

_{([email protected])}

P. Magnan

_{, O. Saint-pé}

_{, F. Bernard}

_{, G. Rolland}

Test chip :

•0.18 µm CMOSCIStechnology

• Dedicated photodiodedoping profiles

•Shallow trench isolations (STI)

•128 x 128 pixel array,3T, 10µm pitch

•Larges photodiodes (>104 _µm²)

•Other test structures (MOSFETs, Gated-diodes…)

Proton irradiation :

•Facilities : KVI, UCL, Isotron

•Energies :7.4 to 200 MeV •Fluences : 5 x 109_{to 3 x 10}11_H+_/cm² 0 1000 2000 3000 4000 0 20 40 60 80 100 120 140 Diode perimeter (µm) R e v e rs e c u rr e n t a t 2 .4 V ( fA )

Peripheral dark current

IC1, 8.8×109 _H+_/cm2_{, 50MeV} IC2, 1.5×1010 _H+_/cm2_{, 100MeV} IC3, 2.4×1010 H+/cm2, 184MeV IC1 no irrad. IC2 no irrad. IC3 no irrad. 0 0.5 1 1.5 2 2.5 3 0 50 100 150 200 Reverse voltage (V) R e v e rs e c u rr e n t (f A )

2000x5µm2 photodiode dark currents

IC1, 8.8×109 H+/cm2, 50MeV IC2, 1.5×1010 H+/cm2, 100MeV IC3, 2.4×1010 H+/cm2, 184MeV IC1 no irrad. IC2 no irrad. IC3 no irrad. _A +

Proton irradiations only induce large

dark current increases… …dominated by the perimetercontribution…

…due to ionizing doseinduced

STItrapped charges and interface states.

Effects on large photodiodes

Overview

Experimental

Effects on CMOS sensors

Perspectives

• No photoresponse degradation, no voltage shift, no gain reduction

No sign of electric field enhancementat the Si-STI interface

Displacement damagesstill play a significant role in uniformity

degradation

• Photodiode hardened against

ion-izing dose effect could conse-quently reduce proton irradiation effects

• In-pixel gated photodiode (B.

Hancock, Proc. SPIE 4306, 2001) seems promising

• Multi level random telegraph

signalswill be studied in detail

0 10 20 30 40 50 60 1 1.5 2 2.5 3 3.5 4x 10 -15 Time (s) D a rk c u rr e n t (A ) Proton induced RTS 0 1 2 3 4 5 6 0 0.2 0.4 0.6 0.8 1

Dark current (fA)

A c ti v a ti o n e n e rg y ( e V )

Activation energies after 50 MeV 8.8×109 H+/cm2

pixel value mean value

Displacement damageseffects on mean dark current are negligible…

… in front of ionizing dose: peripheral STIis responsible Goal : Study ofproton irradiationeffects onCMOS sensors

manufactured in adeep submicrontechnologydedicated to imagingapplications

Test structures :pixel array + isolated large photodiodes

Main result : Proton irradiations mainly induce dark current increases due to ionizing interactions

101 102 103

10-16 10-15 10-14

Displacement damage dose (TeV/g)

D a rk c u rr e n t in c re a s e ( A )

Dark current increase vs. displacement damage dose

Measurement

Computed displacement contribution

101 102

10-16 10-15 10-14

Ionizing dose (Gy)

D a rk c u rr e n t in c re a s e ( A )

Dark current increase vs. ionizing dose

Proton irrad.

Proton irrad. without hot pixels

60_{Co irrad. (worst case)}

0 1 2 3 4 5 6

100 101 102 103

Dark current (fA)

P ix e l c o u n t 50 MeV 8.8x109 H+/cm2 Measurements Ionizing dose estimation