Transcript Presentazione di PowerPoint - Istituto Nazionale di Fisica

LNS
The new generation of SPAD
Single Photon Avalanche Diodes arrays
Salvatore Tudisco
I Workshop on Photon Detection - Perugia 2007
The collaboration started in the
2004 to realise single device and
first array prototypes
- The Silicon Photomultiplier
- Arrays for imaging
Microelectronics
SPAD
High Boron (P+) concentration
reduce the Breakdown voltage
p-n junction reversely biased above the
breakdown voltage
N-
CMOS planar technology
cathode
P+
1 m SiO2
Si <100>
Buried junctions p--p+ -n- :
P+ sinkers: reduce the contact
resistance of the anode and provide a
low resistance path to the avalanche
current
N- gettering region: impurities
reduction
• P- high Breakdown voltage  to prevent peripheral effects
• P+ to reduce the series resistance  substrate insulation  integration of many elements
E. Sciacca et al., IEEE Trans. on el. dev. 50 (2003) 4
E. Sciacca et al., IEEE Photonics Tech. Lett. 18 (2006) 15
Many elements integration

simple quenching strategy
Psasive Quenching
100 k
50 
SPAD Signal
Rise time: 500 ps
Fall time: 30 ns
Recovery time: 1,5 s
(increase with RL)
Important for the applications (SiPM)
SPAD PERPORMANCES
 Photodetection Efficiency

 Dark Counting Rate
 Timing
 Afterpulsing
Photodetection Efficiency
E.V. 10%
E. Sciacca et al., IEEE Trans. on el. dev. 50 (2003) 4
M. Belluso et al. Mem. SAIT Suppl. 9 (2006) 430
SPAD PERPORMANCES
 Photodetection Efficiency
 Dark Counting Rate

 Timing
 Afterpulsing
d=20 m
SPAD
cooler
counter
S. Privitera et al. submited to NIMA
Single photon regime
SPAD PERPORMANCES
400
 Photodetection Efficiency
 Dark Counting Rate
 Timing

 Afterpulsing
350
Counts
300
Many photons regime
9000
250
200
TRIGGER
  60 ps
TDC
100
7000
50
6000
0
laser pulse
408 nm
60 ps FWHM
5000
4000
Laser
150
8000
Counts
  120 ps
10
CH #
SPAD1
CH #
SPAD2
10,5
11
11,5
12
Time [ns]
3000
Diffusion tail  carrier diffusion in neutral
layer  delay to avalanche trigger
2000
1000
0
10,5
11
Time [ns]
11,5
S. Tudisco et al. Nuclear Physics B – proc. supl. 150(2006)317
Finocchiaro et al. IEEE Trans. on Nucl. Scie. 52(2005)3040
SPAD PERPORMANCES
 Photodetection Efficiency
 Dark Counting Rate
 Timing

 Afterpulsing
Single photon regime
laser pulse
337 nm
resolution  2 ns
+ dye for wave
length-shift
Many photons regime
SPAD PERPORMANCES
 Photodetection Efficiency
 Dark Counting Rate
 Timing
 Afterpulsing

TRIGGER
Dark event
Multi Hits
TDC
CH #
After-Pulses
Distribution of successive
events to a primary
avalanche
uncorrelated dark counts
S. Privitera et al. Submit. To NIMA
SPAD PERPORMANCES
 Photodetection Efficiency
 Dark Counting Rate
 Timing
 Afterpulsing


Power law ?
the two contributions in 10 s
 After the subtraction of the
uncorrelated dark background
S. Privitera et al. submit. to NIMA
SPAD ARRAY:
1st prototype 5x5
20 m diameter, 160 m pitch
Anodes
Dark count rate distribution over 750
pixels (30 arrays)
E. Sciacca IEEE Photonics Technology Letters
18 (13-16) (2006) 1633
SPAD ARRAY
Optical Cross-Talk
the avalanche multiplication process
produce photons
Isolation trench
- 80 m attenuation length
- 10-5 photons per carrier crossing the junction
2mV/div
Electrical Cross-Talk
A1
A5
100 mV/div
1st observation
Induction; field fluctuations  Common Substrate
S. Privitera et al. submit. to NIMA
SPAD ARRAY
Time and Spatial correlations
TRIGGER
Pixel 5-1
Multi Hits
TDC
CH #
Piexls 4-1, 4-2, 4-3, 3-1, 1-1
Two contributions:
Prompt < 2 ns Delayed 2 ns  3 s
START
Probability:
Prompt  10-5
Delayed  10-3
SPAD ARRAY
Cross-Talk STOP
Time and Spatial
correlations
Afterpulses 5-1
-Cross-talk and Afterpulsing similar trend,
different slop
- No correlation with distances
S. Privitera et al. Submit. to NIMA
SiPM Configuration
Laser Pulse
 = 408 nm
FWHM = 50 ps
VA
RL
SPAD
IOUT
QDC channels
Oscilloscopio
QDC
ADC
QDC or ADC channels
S. Privitera et al. submit. to NIMA
A.Campisi et al. NIM A 571 (1-2) (2007)350
Laser Pulse
 = 408 nm
FWHM = 50 ps
Event generator
n° fired pixels
parm. intensity
Pixel ON
Montecarlo
Simulations
Cross-talk generator
parm. Probability
Cross-talk generator
parm. dispersion
Increasing
the probability
Fill the spectrum
Decreasing
the dispersion
Conclusion
Single device performances (20m)
• PDE: ~ 45% @ 550 nm
• Dark counting rate: ~ 400 cps @ 25 °C, ~ 100 cps @ 15°C 20
• Timing: ~ 160 ps many-photons regime, ~ 300 ps single photon regime
• Afterpulsing: ~ 10-3 pulses for primary avalanche
Limitations:
• full recovery ~ 1,5 s
5X5 Array performances (20m)
• Dark Counts uniformity: ~ 10%
• Cross-Talk: prompt ~ 10-5 pulses for trigger
delayed ~ 10-3 pulses for trigger
No distance dependence
• SiPM configuration: poor resolution
peak sensing (ADC) better then charge sensing (QDC)
2007 - 1st SiPM prototype (~ 5000 pixels), 1st array for imaging