Irradiation Goals
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Irradiation Goals • Confirm that the breakdown performance improves with dose-Done • Check that breakdown does not appear after inversion on n-type sensors-Done • Confirm I bias , V dep changes as expected for proton/neutron irradiation • Test CCE, resolution, etc. performance after proton irradiation with pixel telescope
description
Irradiation Goals. Confirm that the breakdown performance improves with dose-Done Check that breakdown does not appear after inversion on n-type sensors-Done Confirm I bias , V dep changes as expected for proton/neutron irradiation - PowerPoint PPT Presentation
Transcript of Irradiation Goals
Irradiation Goals
• Confirm that the breakdown performance improves with dose-Done
• Check that breakdown does not appear after inversion on n-type sensors-Done
• Confirm Ibias, Vdep changes as expected for proton/neutron irradiation
• Test CCE, resolution, etc. performance after proton irradiation with pixel telescope
Proton Irradiation
• Irradiated 2 sets (n-type,p-type) of phi sensors and R sensors– Phi sensor: 1.47x1015 p/cm2 → 9x1014 niel/cm2 (7 years @ 8mm)– R sensor: 1.4x1015 p/cm2 → 8.5x1014 niel/cm2 (6.6 years @ 8mm)
• Built 1 set into double-R and double-Phi modules for FNAL test beam and laser test
• Other set used for CV measurements
Phi Sensors R Sensors
N-type R Sensor CV
2439-10C (N-type R-sensor)
0.8
0.85
0.9
0.95
1
1.05
-1000 -800 -600 -400 -200 0
V
1/C
²
Post-irradiated
Pre-irradiated
2439-10C (n-type R-sensor)
y = -6.309E-05x + 9.764E-01
y = 2.309E-16x + 1.012E+00
0.8
0.85
0.9
0.95
1
1.05
1.1
-1000 -900 -800 -700 -600 -500 -400 -300 -200 -100 0
V
1/C
²
Pre-irradiatedSeries7Post-anneal (10 kHz)lowhighLinear (low)Linear (high)
After 30 min@60 C equiv. 11 day@20 CDep V:~560 V
2439-10C (n-type R-sensor)
y = -6.309E-05x + 9.764E-01
y = 2.309E-16x + 1.012E+00
0.95
1
-800 -700 -600 -500 -400 -300 -200 -100
V
1/C
²
Pre-irradiatedSeries7Post-anneal (10 kHz)lowhighLinear (low)Linear (high)
With no annealing, it is difficult to say if part depletes. The three clear kinks in the CV correspond to unirradiated left , partly irradiated middle, and fully irradiated right of sensor. So annealed to lower depletion point.
P-type R Sensor CV
2488-01E (P-type R sensor)
y = -5.725E-05x + 1.079E+00
y = -5.008E-06x + 1.107E+00
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0.85
0.9
0.95
1
1.05
1.1
1.15
1.2
-1000 -900 -800 -700 -600 -500 -400 -300 -200 -100 0V
1/C
²
Pre-irradiatedSeries7Post-anneal (10 kHz)lowhighLinear (low)Linear (high)
2488-01E (P-type R sensor)
y = -5.725E-05x + 1.079E+00y = -5.008E-06x + 1.107E+00
1.07
1.12
-800 -700 -600 -500 -400 -300 -200
V
1/C
²
Pre-irradiatedSeries7Post-anneal (10 kHz)lowhighLinear (low)Linear (high)
After 30 min@60 C equiv. 11 day@20 CDep V:~530 V
2488-01E (Pre-annealing)
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0.95
1
1.05
1.1
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-1000 -800 -600 -400 -200 0
V
1/C
²
Post-irradiated
Pre-irradiated
With no annealing, it is difficult to say if part depletes. The three clear kinks in the CV correspond to unirradiated left , partly irradiated middle, and fully irradiated right of sensor. So annealed to lower depletion point.
Laser Test-Proton IrradiationN-type Irr N-type non-Irr
P-type Irr P-type non-Irr
• Laser tested double-R and double-phi modules while cooled (~-7 C at sensor)
– Stability of laser focus, intensity difficult to control
• See similar fraction (Irr/Non-Irr) of charge in both p-type and n-type
– Somewhere between 50-70%• 8.5x1014 niel/cm2
– From previous proton irradiaton on minis expect 40% (1.8x1015 niel/cm2)
68% (6.6x1014 niel/cm2)• With annealing to minima,
expect 10-15% more charge collected
– Will try to anneal during FNAL test-beam
Proton Irradiation Conclusions
• From RD48 damage constants, expect ~480 V depletion voltages after annealing for measured dose of proton for n-type and p-type silicon– We measured somewhere between 530-560 V for the
n-type and p-type
• From previous proton irradiations of n-in-p minis, we expect to collect ~60% of the max charge– From laser, get 50-70% pre-annealing– Will confirm with test beam
• Thus, I would expect modules to be fully efficient after this dose (6.6 years @ 8 mm)
2433-05E p-type R-sensor
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20
30
40
50
60
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80
0 100 200 300 400 500 600 700
Bias Voltage
Cu
rre
nt
(uA
)
Before Irradiation
After GammaIrradiation
After NeutronIrradiation (-14.4 C)
2433-12A p-type Phi
0
50
100
150
200
250
0 100 200 300 400 500 600
Bias Voltage
Cu
rre
nt
(uA
)
Before Irradiation
After Gamma Irradiation
After Neutron Irradiation
Irradiation Results-IV
2439-10C n-type Phi
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50
100
150
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250
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Voltage
Cu
rren
t (u
A)
Before Irradiation
After GammaIrradiationAfter NeutronIrradiation
2440-06E n-type R
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100
150
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250
300
0 200 400 600 800
Bias Voltage
Cu
rre
nt
(uA
)
Before Irradiation
After GammaIrradiation
After NeutronIrradiation (-14.5 C)
P-type
N-type
5x1013 /cm2
1.5x1014 /cm2
1.5x1014 /cm2
1.5x1014 /cm2
1011 1012 1013 1014 1015
eq [cm-2]
10-6
10-5
10-4
10-3
10-2
10-1
I /
V
[A/c
m3 ]
n-type FZ - 7 to 25 Kcmn-type FZ - 7 to 25 Kcmn-type FZ - 7 Kcmn-type FZ - 7 Kcmn-type FZ - 4 Kcmn-type FZ - 4 Kcmn-type FZ - 3 Kcmn-type FZ - 3 Kcm
n-type FZ - 780 cmn-type FZ - 780 cmn-type FZ - 410 cmn-type FZ - 410 cmn-type FZ - 130 cmn-type FZ - 130 cmn-type FZ - 110 cmn-type FZ - 110 cmn-type CZ - 140 cmn-type CZ - 140 cm
p-type EPI - 2 and 4 Kcmp-type EPI - 2 and 4 Kcm
p-type EPI - 380 cmp-type EPI - 380 cm
Low dose (~4-5x10-13 neq/cm2, expected 5x10-13 neq/cm2)High dose (~1.3-1.6x10-14 neq/cm2, expected 1.5x10-14 neq/cm2)
Error dominated by uncertainty in annealing time
2433-05E
y = -0.0061x + 0.0788
y = -3E-05x + 1.0977
0
0.2
0.4
0.6
0.8
1
1.2
-600 -500 -400 -300 -200 -100 0 100
V
1/C
²
1/C² < 150
1/C² > 150
Pre-irradiated
Linear (1/C² < 150)
Linear (1/C² > 150)
Neutron Irradiation Results-CV
2440-06E
y = -5E-05x + 0.9962
y = -0.0032x + 0.0549
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0.4
0.6
0.8
1
1.2
-600 -500 -400 -300 -200 -100 0
V
1/C
²
1/C^2<290
1/C^2>290
Pre-irradiated
Linear (1/C^2>290)
Linear (1/C^2<290)
2433-05E
y = -0.0003x + 1.0505
y = -0.0028x + 0.0665
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0.2
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0.6
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1
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1.4
-600 -500 -400 -300 -200 -100 0
V
1/C
²
1/C² > 380
1/C² < 380
Pre-irradiated
Linear (1/C² > 380)
Linear (1/C² < 380)
2439-10C
y = -0.0003x + 1.0181
y = -0.0037x + 0.0752
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0.8
1
1.2
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-600 -500 -400 -300 -200 -100 0
V
1/C
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1/C^2>300
1/C^2<300
Pre-irradiated
Linear (1/C^2>300)
Linear (1/C^2<300)
P-type
N-type
VdepPre=81V Vdep
Post=167 V Vdep=86 V
5x1013/cm2
1.5x1014/cm2
1.5x1014/cm2
1.5x1014 /cm2
VdepPre=81V Vdep
Post=393 V Vdep=312 V
VdepPre=21V Vdep
Post=299 V Vdep=320 V VdepPre=25V Vdep
Post=277 V Vdep=302 V
Irradiation Results• Irradiation of ~136 kRads with
6 MeV photons– Hard breakdown behaviour
improved greatly due to radiation
• Charge in oxide– Soft breakdown behaviour
(semi-ohmic) improved only in 1 of 3 sensors (2 unchanged)
• Should improve with neutron/proton irradiation which causes more bulk damage
• Irradiation with neutrons at Ljubljaba– Breakdown behaviour gone– P-type and n-type IV similar after doses– For neutron irradiation, p-type sensors
have higher Vdep • 390 vs. 280-300 after 1.5x1014 neq/cm2
– Expect Vdep to be similar for n and p-type sensors with ~1014 neq/cm2 proton irradiations
– Changes in depletion voltages close to expected:
• From TDR, 1.3x1014neq/cm2 in 5 month LHC dose: Vdep=250 V
• Scaling for 5x1013neq/cm2, measured Vdep=86 V, expected Vdep=96 V
• Scaling for 1.5x1014neq/cm2, measured Vdep=302-320 V, expected Vdep=288 V
– Differences between measured and expected may be due to annealing
