Download V bias

Présentation SiPM.
Sommaire:
1- Vue d’ensemble des photo-détecteurs
2- Généralités sur les SiPMs.
3- Caractérisation.
- en continue
- en dynamique
- sous lumière
4- Applications actuelles et futures.
- merci à Nicoleta & Véronique pour l’aide qu’elles m’ont fourni
Vincent CHAUMAT
.
LAL – RAPA- Sept 2008
A look on photon detectors characteristics
VACUUM
TECHNOLOGY
SOLID-STATE
TECHNOLOGY
PMT
MCP-PMT
HPD
PN, PIN
APD
GM-APD
Blue
20 %
20 %
20 %
60
70 %
50 %
30%
Green-yellow
40 %
40 %
40 %
80-90 %
60-70 %
50%
Red
6%
6%
6%
90-100
80 % %
80 %
40%
Timing / 10 ph.e
 100 ps
 10 ps
 100 ps
tens ns
few ns
tens of ps
Gain
106 - 107
106 - 107
3 - 8x103
1
200
200V
105 - 106
1 kV
3 kV
20 kV
10-100V
100-500V
 100 V
Operation in the magnetic field
 10-3 T
Axial magnetic
field  2 T
Axial
magnetic field
4T
No sensitivity
No sensitivity
No sensitivity
Threshold sensitivity (S/N1)
1 ph.e
1 ph.e
1 ph.e
100 ph.e
10 ph.e
1 ph.e
sensible
bulky
compact
sensible,
bulky
Photon
detection
efficiency
Operation voltage
Shape characteristics
Vincent CHAUMAT
LAL – RAPA- Sept 2008
robust, compact, mechanically rugged
PIN, APD & GM-APD
PIN
APD
GM-APD
+
p+ n
P+ active area
Depletion region
P+ - Type
p--type epitaxial layer
P-N junction edge
N – Type Silicon
N-Type Silicon
p+-type silicon (substrate)
p-n junction
p-n junction, Vbias < VBD
p-n junction, Vbias > VBD
Gain = 1
Gain = M (~ 50-500)
- linear mode operation-
Gain → infinite
-Geiger-mode operation-
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Des GM-APD aux SiPM
• GM-APD – ne donne pas d’information sur l’intensité lumineuse
Current (a.u.)
Standardized output signal
Rquenching
+
p+ n
p--type epitaxial layer
p+-type silicon (substrate)
-Vbias
Time (a.u.)
• SiPM (présenté dans les années 90 par Zadigov et Golovin)
– Matrice de µ pixel en parallèle / chaque pixel = GM-APD + Rquench
– Le signal de sortie est proportionnel au nombre de pixels déclanchés
Front contact
Al
Out
Current (a.u.)
h
Rquenching
Two pixels fired
Rquench
One pixel
fired
ARC

n+ p
n+
Three pixels
fired
GM-APD
p
n pixels
p+ silicon wafer
Back contact
Vincent CHAUMAT
-Vbias
- Vbias
LAL – RAPA- Sept 2008
Time (a.u.)
Différents design de SiPM -1
FBK (Italie)
Geometric characteristics:
• area: 1 x 1 mm2
625 pixels /40 x 40 m2 pixel size
40 µm
Front-side illumination
Poly-silicon resistor
Hamamatsu (Japon)
Geometric characteristics
• area: 1 x 1 mm
100 pixels /100 x 100 m2 pixel size
100 µm
Photos done at LAL mechanical service, thanks to B. Leluan
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Différents design de SiPM -2
Photonique (Russie)
Geometric characteristics
• area 1x1 mm2
556 pixels / 43 x 43 µm2 pixel size
Zecotec (Russie)
Front-side illumination
Metal-resistive-semiconductor
Geometric characteristics
• area 1.08 x 1.08mm2 (1,17 mm2)
1050 pixels/ ~ 33 x 33 µm2 pixel size
33 µm
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Listes des paramètres caractérisés
– Static characteristics
• breakdown voltage
• leakage current
• quenching resistance
– Dynamic characteristics
•
•
•
•
time structure of the output signal (e.g. rise time, recovery time)
gain
capacitance
noise (e.g. thermal generation, afterpulses, optical cross-talk estimation)
– Light characteristics
• photon detection efficiency v.s. wavelength (e.g. white lamp and monocromator)
• response linearity v.s. incident optical power density (e.g. dynamic range)
• One set-up for measurements in dark conditions
•
Based on the hypothesis that the signal generated by an absorbed photon (the real signal) or by a thermal generated carrier (dark count signal) are
identical, the AC characterization can be done studying the dark signals
• One set-up for measurements in the presence of the light
Vincent CHAUMAT
LAL – RAPA- Sept 2008
The set-up for the tests in dark conditions
Hardware:
- amplifier
- MITEQ – 0,01-500 MHz / 50 / 45dB gain / 5mV RMS noise
- Fisher Bioblock climatic chamber -10 to +50°C, PC temperature controlled through RS232
- Keithley Source Meter 2611 (Vmax = 200V, Isensibility  2 pA, connections through triaxial cables)
- home-made counter with variable threshold on the input signal
- TDS 5054 oscilloscope (500 MHz, 5 GS/s)
- Pt100 ohm thermometer read by an Keithley 2700 data acquisition system
Software:
- automatic IV and dark rate measurements by LabView program and C++ program
- gain, afterpulses & cross-talk analysis by LabView program
CHAUMAT
- Vincent
automatic
monitoring of the Pt100 thermometer
bySept
LabView
software
LAL – RAPA2008
Static characteristics
• IV reverse characteristic (25°C):
1,00E-06
Reverse current (A)
1,00E-07
1,00E-08
VBD
1,00E-09
30
31
32
33
34
35
36
37
38
Abs Voltage (V)
-
Pre-breakdown current
- carriers generated both in the bulk and
surface depleted region
- linear with Vbias
Post-breakdown current
- determined by the dark events and the
charges carried by each event (gain)
- parabola with Vbias
VBD  34V @ 25°C
Ipost BD  1µA @ V=4V
2,5E-03
- IV forward characteristic (25°C)
Forward current (A)
2,0E-03
1,5E-03
1,0E-03
•
•
5,0E-04
0,0E+00
0
0,2
0,4
0,6
0,8
1
1,2
1,4
1,6
- exponential behavior given by the
diode equivalent resistor
- linear behavior given by the
quenching resistor
RSiPM ~ 555 
RQ pixel = RSiPM * 625 pixels ~ 350 k
1,8
Abs Voltage (V)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Temperature dependence static characteristics
1,00E-06
IV W20-B10T6V2PD-3
•VBD growths with the temperature
•VBD ~ 80 mV/°C  ~ 0,25% / °C
Reverse current (A)
1,00E-07
1,00E-08
IV 25°C
IV 20°C
IV 15°C
IV 10°C
base line 25°C
base line 20°C
base line 15°C
base line 10°C
break down 25°C
break down 20°C
break down 15°C
break down 10°C
break down point 25°C
break down point 20°C
break down point 15°C
break down point 10°C
Current mesure gain 25°C
Current mesure gain 20°C
Current mesure gain 15°C
Current mesure gain 10°C
breackdown (gain) 25°c
breackdown (gain) 20°c
breackdown (gain) 15°c
breackdown (gain) 10°c
Linéaire (base line 25°C)
Linéaire (base line 20°C)
Linéaire (base line 15°C)
Linéaire (base line 10°C)
Polynomial (break down 25°C)
Polynomial (break down 20°C)
Polynomial (break down 15°C)
Polynomial (break down 10°C)
25°C
20°C
15°C
10°C
1,00E-09
32
33
34
35
36
37
38
Abs Vbias (V)
1,00E-05
IV W20-B10T6V2PD-3
Reverse current (A)
1,00E-06
•Diminution du courant d’obscurité
avec la température à overvoltage
constant.
1,00E-07
1,00E-08
25°C
20°C
15°C
10°C
1,00E-09
0
1
2
3
4
5
6
Overvoltage (V)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
SiPM signal shape
Shape avalanche photon unique
• Fall time: qq nS (limité par les instruments de mesure)
• Recovery time: ~50nS
Vincent CHAUMAT
LAL – RAPA- Sept 2008
SiPM gain
• Defined as the charge developed in one pixel by a primary charge carrier:
Gain 
Qmicrocell
C
 VBIAS  VBD 
 microcell
e
e
• Linear increasing with the bias voltage
• the triggering probability increases linear with the bias voltage
• Pixel capacitance – the slope of the linear fit gain v.s. bias voltage
2,0E+06
W3-B3-T6V1PD 25°C
W20-B10-T6V2PD 25°C
Linéaire (W3-B3-T6V1PD 25°C)
Linéaire (W20-B10-T6V2PD 25°C)
1,8E+06
• G ~ 1,2 x 106 @ Vbias = 37 V
• G ~ 1,6 x 106 @ Vbias = 38 V
• Cpixel ~ 50 fF
1,6E+06
1,4E+06
gain
1,2E+06
1,0E+06
wafer 3
y = 319551x - 9E+06
Cpixel ~ 50fF
8,0E+05
wafer 20
y = 375612x - 1E+07
Cpixel ~55 fF
6,0E+05
4,0E+05
2,0E+05
0,0E+00
27
28
29
30
31
32
33
34
35
36
37
38
39
Bias voltage (V)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
40
Gain temperature dependence
2,5E+06
y = 397643x - 1E+07
R2 = 0,9992
10°C
15°C
20°C
25°C
W20-B10T6V2PD-3
y = 391567x - 1E+07
R2 = 0,9994
2,0E+06
y = 382619x - 1E+07
R2 = 0,9997
1,5E+06
Gain
y = 378436x - 1E+07
R2 = 0,9995
• Gain decreases with the
temperature at fixed reversed bias
• G ~ 0,3 x 105 / °C  ~ 3% / °C
1,0E+06
Gain 25°C
Gain 20°C
Gain 15°C
Gain 10°C
Linéaire (Gain 25°C)
Linéaire (Gain 15°C)
Linéaire (Gain 10°C)
Linéaire (Gain 20°C)
5,0E+05
0,0E+00
32
33
34
35
36
37
38
39
Abs Vbias (V)
2,5E+06
W20-B10T6V2PD-3
• Gain invariant avec la température
à overvoltage constant
2,0E+06
Gain
1,5E+06
1,0E+06
Gain 25°C
Gain 20°C
Gain 15°C
Gain 10°C
Linéaire (Gain 25°C)
Linéaire (Gain 20°C)
Linéaire (Gain 15°C)
Linéaire (Gain 10°C)
5,0E+05
0,0E+00
0
1
2
3
4
5
6
Overvoltage (V)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
SiPM noise -1
• Dark count rate
– the main source of noise limiting the SiPM performances
– the number of false photon counts/ second registered by the SiPM in the
absence of the light
– three main contributions:
• thermally
• afterpulses
– through Shockley-Read-Hall generation-recombination centers
– carriers trapped during the avalanche discharging and release
after, triggering a new avalanche
• optical cross-talk – during an avalanche discharge, photons are emitted
– these photons can trigger an avalanche in an adjacent cell
• dark signals
• s – single pixel pulse (thermal generated)
• d – double pixel pulse (optical cross-talk)
• a – pulses with small amplitude, following a
single or a double pulse (afterpulses)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
SiPM noise -2
1,0E+07
Wafer 20 / B10-T6V2PD - 25°C
35V
35,5V
36V
36,5V
37V
37,5V
38V
38,5V
39V; dV=5V
dark count rate (Hz)
1,0E+06
1,0E+05
1,0E+04
1,0E+03
1,0E+02
1,0E+01
1,0E+00
0
100
200
300
threshold (mV)
• Dark count rate (0,5 pe. threshold)
• ~ 2 MHz @ Vbias = 37 V (V= 3V)
• ~ 3 MHz @ Vbias = 38 V (V= 4V)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
400
500
600
Photon detection efficiency of the SiPM
 Traditional PDE:
 PDE of the SiPM:

nr. of output pulses recorded
nr. of photons received by the detector
 SiPM  QE  Ptriggering   geom
QE – the quantum efficiency
• probability that a photon generate an e/h pair in the active region of the device (e.g. n +/p junction of a pixel) wavelength dependent
Ptriggering – the avalanche efficiency
• probability that an electron generate an avalanche in the device (e.g. Π region of a pixel) – voltage dependent
εgeom – the geometrical efficiency
• Active surface to total surface ratio
p--type epitaxial layer
+
p+ n
p+-type silicon (substrate)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Set-up for tests in light conditions
X
Calibrated
photodiode
CCD camera
Data
acquisition
system
SiPM
Halogen light source
(100W)
Y
Grating monochromator
350-800nm
Z
3D translation tables
Optical bench
 Principle method for the PDE measurement:
 low incident flux (~ 107 incident photons /s/mm²) – to avoid the SiPM saturation
 the number of the incident photons – evaluated with a calibrated photodiode
 the number of the photons recorded by the SiPM – evaluated by two methods:
• DC method: (Iunder illumination- Idark)/Gmean exp
• Gexp mean – the exp. average value of the gain determined from the charge distribution
• AC counting method: Nsignals under illumination – Nsignals dark
• with particular attention on the acquisition parameters to eliminate the afterpulses and the
cross-talk
 a good agreement (within 5%) has been found in between the two methods
Vincent CHAUMAT
LAL – RAPA- Sept 2008
PDE
16
Mesure de l'efficacité quantique du SiPM T6 W20 IRST, gain thermic, Vb 34V T= 22°C
PDE 35,5V sans filtre
PDE 36V sans filtre
14
PDE 36,5V sans filtre
PDE 37V sans filtre
PDE 37,5V sans filtre
12
PDE 38V sans filtre
PDE en %
10
8
6
4
2
0
380
430
480
530
580
630
680
longueur d'onde en nm
Vincent CHAUMAT
LAL – RAPA- Sept 2008
730
780
Linéarité
1,00E+10
linéarité-Saturation SiPM W20 T6 IRST 37V à T = 22°C et Vb 34 V
Nr. of photons/mm2/s detected by SiPM
1,00E+09
N photons enrg SiPM 37V
Série2
Linéaire (Série2)
y = 0,0988x + 91048
1,00E+08
1,00E+07
1,00E+06
1,00E+05
1,00E+06
1,00E+07
1,00E+08
1,00E+09
1,00E+10
Nr. of incident photons/mm^2/s
Vincent CHAUMAT
LAL – RAPA- Sept 2008
1,00E+11
1,00E+12
Applications & future
• T2K (usine à neutrino) 50000 SiPMs utilisés sur 5 détecteurs
• ILC calorimetre hadronique (étude)
• Biologie: Pet détection, fluorescence, life time mesurement,
etc…
• Plus grande surface active (9mm²) par pixel
• Matrice de SiPM -FBK -SensL …. (bonne efficacité
géométrique, résolution position 2D, accroissement des
surfaces de détecteurs)
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Slides supplémentaires
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Model of GM – APD & passive quenching (1)
• Pioneering work done in the 1960 to model micro-plasma instabilities
– RCA company by J. R. McIntire, IEEE Trans. Electron Devices, ED-13 (1996) 164
– Shockley Research Laboratory by R. H. Haitz, J. App.. Phys. Vol. 36, No. 10 (1965) 3123
• First order circuit model of the GM-APD with passive quenching
• Diode
DIODE
S
VBD
CD
RQ
VBIAS
– Rs – diode series impedance (~ 1 k)
– Cd – total junction capacitance
– VBD – breakdown voltage
– S – random on-off switching of the
avalanche discharge
RS
• Biasing circuit
– RQ – quenching resistance (> 100 k)
– Vbias – bias voltage
Vincent CHAUMAT
LAL – RAPA- Sept 2008
Model of GM – APD & passive quenching (2)
DIODE
RQ
S
VBD
VBIAS
CD
RS
current
• OFF condition
– No charge traversing the breakdown region
– S – open
– Cd – charged to Vbias
– i ~ 0 through Rq
• ON condition
imax ~(Vbias – VBD)/RQ
time
V
– Avalanche discharge triggered by a carrier generated in
the breakdown region (e.g. photon or thermal carrier)
– S – closed
– Cd discharge to VBD with a time constant Rs x CD
– Diode current increases to (Vbias – VBD)/RQ (RQ >> Rs)
– Diode voltage decreases from Vbias to VBD
• OFF condition
– S – open
– Cd – recharge again to Vbias with a
time constant RQ x Cd
Vbias
VBD
t0 t1
Vincent CHAUMAT
t2
time
• ready for a new detection
LAL – RAPA- Sept 2008
FBT W20 distribution charge
N
Charge mean :
Charge photon unique
 Charge
BIN  0
BIN i
* Nbcoup BIN i
N
 Nbcoup
Bin  0
BIN i
Nb coup (Hz)
100000
distribution charge avalanche :
distribution charge 37,5V :
distribution charge 36,5V :
distribution charge35,5V :
10000
1000
•Charge moyenne 37.5V : 332fC
•Charge photon unique 37.5 V : 239fC
100
•Charge moyenne 36.5V : 216fC
•Charge photon unique 36.5 V : 169fC
10
•Charge moyenne 35.5V : 227fC
•Charge photon unique 35.5 V : 114fC
Charge (fC)
1
0
200
400
Vincent CHAUMAT
600
800
1000
1200
1400
1600
LAL – RAPA- Sept 2008
SiPM noise -3
• Dark signals
• single pixel pulse (thermal generated)
• two simultaneous pixels pulse (optical
cross-talk)
• pulses with smaller charge, following a
single or a double pulse (afterpulses)
1,0E+07
Wafer 20 / B10-T6V2PD - 25°C
35V
35,5V
36V
36,5V
37V
37,5V
38V
38,5V
39V; dV=5V
dark count rate (Hz)
1,0E+06
1,0E+05
• Dark count rate (0,5 pe. threshold)
• ~ 2 MHz @ Vbias = 37 V (V= 3V)
• ~ 3 MHz @ Vbias = 38 V (V= 4V)
1,0E+04
1,0E+03
1,0E+02
1,0E+01
1,0E+00
0
100
Vincent CHAUMAT
200
300
threshold (mV)
400
500
600
LAL – RAPA- Sept 2008