To cite this document: Virmontois, Cédric and Goiffon, Vincent and Magnan, Pierre and
Girard, Sylvain and Inguimbert, Christophe and Petit, Sophie and Rolland, Guy and
Saint-Pé, Olivier Displacement Damage Effect Due to Neutron and Proton Irradiations
on CMOS Image Sensors Manufactured in Deep Sub-Micron Technology. (2010) In:
Nuclear and Space Radiation Effects Conference (NSREC), 19 July 2010 - 23 July 2010
(Denver, United States). (Unpublished)
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Displacement Damage Effect Due to Neutron and Proton
Irradiations on CMOS Image Sensor
C. Virmontois
1(cedric.virmontois@isae.fr),
V. Goiffon
1,S. Girard
2, C. Inguimbert
3,O. Saint-Pé
4,
S. Petit
5, G. Rolland
5, P. Magnan
11Université de Toulouse, ISAE, 2CEA, DAM, DIF, 3ONERA, DESP, 4EADS Astrium, 5CNES
Test chip :
0.18 µm CMOSCIStechnology
Dedicated photodiodedoping profiles
128 x 128 pixel arrays,3T, 10µm pitch
Larges photodiodes (>104 µm²)
Proton irradiation :
Facilities : KVI, UCL, TRIUMF
Energies :50 to 500 MeV
Fluences : 5 x 109to 1 x 1011H+/cm²
Neutron irradiation : Facilities : CEA Valduc, UCL
Energies :0.8 to 20 MeV
Fluences : 5 x 109to 1 x 1013N/cm²
Experimental
Overview
Goal : Study ofdisplacement damageeffects onCMOS sensorsmanufactured in adeep
sub-microntechnologydedicated to imagingapplications
Test structures :pixel arrays + isolated large photodiodes
Main result :
Main damage due to displacement is dark current increase
Proton displacement effect
Neutron and proton induce equivalent displacement damage
Analytic model, based on damage energy, could predict dark current increase distribution in APS
Defects responsible of dark current increase are intrinsic defectsprobably in the form of cluster
Effects on in-pixel photodiode
Main defectsinducing dark current increasein
photodiode, after γγγγ-ray (1), proton (2) and neutron (3) irradiations :
Ionizationinduces interface statesin Shallow
Trench Isolation (STI)
Displacement induces point defectsand
clusters of defectsin space charge region (SCR)
Bulk defects Interface states
Annealing
0 0,2 0,4 0,6 0,8 1 1,2 0 50 100 150 200 250 300 Annealing temprature (°C) U n a n n e a le d F a c to r PD 2000x5 µm PD 800x800 µm PD 4000x5 µm APS 38 TeV/g APS 183 TeV/g APS 365 TeV/g APS 20000 TeV/gUnannealed dark current fraction and
DLTS measurements show that defects
inducing dark current increase could be
probably in the form of clusters
Effects on CMOS sensors
No photoresponse degradation, no voltage shift, no gain reduction
No sign of electric
field enhancementat
the Si-STI interface
Neutron induces essentially
Displacement damages Proton induced displacement
damageseffects on mean dark
current arenegligible in front
ofionizing dose 1,E-20 1,E-18 1,E-16 1,E-14 1,E-12
1,E-02 1,E+00 1,E+02 1,E+04
Displacement dose (TeV/g)
Id a rk i n c re a s e ( A ) Experimental results Displacement contributions + 1,E-16 1,E-15 1,E-14 1,E-13
1,E+01 1,E+02 1,E+03 1,E+04
Displacement dose (TeV/g)
Id a rk i n c re a s e ( A ) Experimental results Displacement contributions 0,001 0,01 0,1 1 10 0 0,5 1 1,5 2 2,5 3 3,5 4
Dark current (fA)
R e la ti v e f re q u e n c y Initial 0,4 TeV/g 3,78 TeV/g 37,8 TeV/g 182,5 TeV/g 365 TeV/g
Pixel tail, due to neutron induced displacement,
increases followingdisplacement damage dose
Histogram observations ofdark
current increase due to
neutron irradiationare
compared to estimates based on GEANT 4 calculations of the
recoil spectrum parameters Estimation of dark current increase is calculated usingthe recoil element damage energy
Proportionalitybetween
damage energy anddark
current increase based on
NIEL is used
Analytic model is convolved
withionization fit to obtain proton induced dark current increase distribution. 0,001 0,01 0,1 1 10 100 0 1 2 3 4 5 6 7
Dark current increase (fA)
R e la ti v e f re q u e n c y Measurements 39 TeV/g Measurments 183 TeV/g Measurement 365 TeV/g model 39 TeV/g model 183 TeV/g model 365TeV/g 0,001 0,01 0,1 1 10 0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 Dark current increase (fA)
R e la ti v e f re q u e n c y Proton 39 TeV/g Simulation
Dark current at 23°C (fA)
A c ti v a ti o n e n e rg y ( e V )
Dark current at 23°C (fA)
A c ti v a ti o n e n e rg y ( e V )
