1/14 Characterization of P-type Silicon Detectors Irradiated with Neutrons M.Miñano 1, J.P.Balbuena...
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Transcript of 1/14 Characterization of P-type Silicon Detectors Irradiated with Neutrons M.Miñano 1, J.P.Balbuena...
1/14
Characterization of P-type Silicon Detectors Irradiated with Neutrons
M.Miñano1, J.P.Balbuena2, C. García1, S.González1, C.Lacasta1, V.Lacuesta1, M.Lozano2,
S. Martí i García1, G. Pellegrini2,3, M. Ullán2
(1) Instituto de Física Corpuscular, IFIC (CSIC-UVEG), Valencia, Spain(2) Instituto de Microelectrónica de Barcelona, CNM-IMB (CSIC), Bellaterra, Spain
(3) Departamento de Electrónica, Informática y Automática, Universidad de Gerona, Spain
3rd Workshop on Advanced Silicon Radiation Detectors, Barcelona, Spain 14 April 2008
2/14
Outline
I. Fabrication process
II. P-type strip detectors irradiated with neutrons
III. Setup (Laser & Radiactive Source)
IV. I-V results
V. Q-V results
VI. Summary and Outlook
3/14
I. Fabrication Process Detectors have been fabricated in the Clean Room facility of CNM-IMB
Rd50 Mask
Designed by the RD50 Collaboration Double side processing One metal layer
Structures
26 microstrips detectors Polysilicon biasing resistors Capacitive coupling P-spray insulation No p-stops
20 pad detectors 12 pixel detectors 8 test structure sets
4/14
II. P-type strip detectors irradiated with neutrons
1 MeV equivalent neutron irradiation at TRIGA nuclear reactor in Ljubljana, Slovenia.
FLUENCES
1X1014 n/cm2
3x1014 n/cm2
1x1015 n/cm2
3x1015 n/cm2
8x1015 n/cm2
• Area: 1x1 cm2
• 130 strips, width: 32 m
• Pitch: 80 m
• Thickness: 300 m
• Multiple guard ring
• Surface isolation: p-spray
Wire bonding
No annealing
DOFZ, MCz substrates to evaluate
5/14
III. Laser Setup
Laser
strip sensorTrigger
Signal
Horizontal scale
20mV
1V
Real signal viewed at 70V in the scope
Laser light is generated by exciting a laser source with an external pulsed signal
(2 V and 1 MHz rate)
Laser properties:
=1060 nm (Near Infrared)
Laser energy of photons=1.170 eV
6/14
III. Radiactive Source Setup
90Sr
strip sensor
Signal
Trigger
Horizontal scale
Photomultiplier
200 mV /div
2 mV /div
Real signal viewed at 300V in the scope
Measurements are used to calibrate the laser measurements
- source
7/14
Laser OscilloscopeFaraday CagePhotomultiplier
and Scintillator
Power SupplyPM power supply
freezer
Sensor cage Source
8/14
0
2
4
6
8
10
12
14
16
0 200 400 600 800 1000
V (volts)
Cu
rren
t (
A) 3E14 n/cm2
1E15 n/cm2
3E15 n/cm2
8E15 n/cm2
IV. Current vs Voltage: DOFZ T = -40oC
For the sensor irradiated with 1x1014 n/cm2 we observed an extremely early break
9/14
IV. Current vs Voltage: MCz
0
0,5
1
1,5
2
2,5
3
3,5
4
0 200 400 600 800 1000
V (volts)
Cu
rren
t (u
A)
1E14 n/cm2
3E14 n/cm2
1E15 n/cm2
T = -40oC
10/14
0
2
4
6
8
10
12
14
16
18
20
22
24
26
0 100 200 300 400 500 600 700 800 900V (volts)
Q (
ke)
Non-irradiated
3E14 n/cm2
1E15 n/cm2
3E15 n/cm2
8E15 n/cm2
V. Charge vs Voltage: DOFZ T = -40oC
11/14
V. Charge vs Voltage: MCz
0
5
10
15
20
25
30
0 200 400 600 800 1000
V(volts)
Q (
ke)
Non-irradiated
1E14 n/cm2
3E14 n/cm2
1E15 n/cm2
T = -40oC Global warming? Effect due to high
current level?
Systematic error?
12/14
Neutron Irradiation:
Comparison DOFZ vs MCz substrates at the same fluences
0
5
10
15
20
25
30
0 200 400 600 800 1000
V (volts)
Q (
Ke
)
DOFZ
MCz
Non-irradiated3 x 1014 neq/cm2
1 x 1015 neq/cm2
13/14
Degradation after neutron irradiation: Q-
0
5
10
15
20
25
30
0 2E+14 4E+14 6E+14 8E+14 1E+15 1,2E+15
fluence (cm-2)
Q (
ke
)
MCz
DOFZ
V=500V
Collected charge is unaffected by the silicon substrate type
14/14
VI. Summary and Outlook P-type strip sensors have been fabricated in CNM-IMB and irradiated with neutrons at several fluences at the TRIGA Nuclear Reactor in Ljubljana.
Detectors on alternative substrates (MCz, DOFZ) have been evaluated.
Current and Collected charge vs Voltage measurements have been done.
Even after the highest neutron fluence (equivalent to 10 years of the sLHC operation) the detectors are still operational.
For instance, at 8.0 1015 n/cm2 ~7300 e- are collected at 900V.
MCz charge collection at high bias voltages to be understood.
The neutron radiation hardness does not depend on the substrate technology.
Near future plans, ALIBAVA system will be used to performance the charge collection measurements and signal characterization.
More neutron and proton irradiated detectores will be characterized in the coming months.