Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
Sergio CovaIEEE-LEOS Distinguished Lecturer
Photon Counting Microdetectors and Applications:Retrospect and Prospect
Politecnico di Milano – DEI, Milano, Italy
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Biography - Dr. Sergio Cova
Full professor of Electronics since 1976 @ Politecnico di Milano (POLIMI), Italy
Author of over a hundred and seventy papers in international refereed journals and conferences and of five international patents (USA and Europe)
Pioneered the development of Single-Photon Avalanche Diodes (SPAD), inventing the active-quenching circuit (AQC). His research group developed AQCs in successive generations and was the first (and so far is the only one) to develop monolithic integrated AQCs.
Contributed to diversified applications of photon-counting detectors: fluorescence measurements for DNA and protein analysis and single-molecule studies; characterization of optical fibers and laser; adaptive optics systems in telescopes; non-invasive testing of ULSI circuits; and others.
In 2005 established with other colleagues of Politecnico di Milano the university spin-off company MPD Micro-Photon-Devices, intended for producing industrially and making widely available to experimenters the photon counting microdetectorsdeveloped in the research at POLIMI.
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Outline
Introduction: Single Photon (SP) Detection
Micro-Detectors: Single Photon Avalanche Diodes
(SPAD) and associated electronics
Application Cases
Conclusions and Outlook
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Introduction: Single Photon (SP) Detection
Why SP Detection
How to Detect SP
Why Solid-State SP Micro-Detectors
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Electronic Noise impairs Detector Sensitivity
ELECTRONICSLOADDETECTOR
Detector Signal
1 Photon 1 Electron
Detector Noise(Primary Dark-Current)QE
Electronic Noise:dominant !!
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Overcoming the Electronic Noise Limit by
Detecting SP
ELECTRONICSLOADDETECTOR
Detector Signal
1 Photon 1 Electron
Detector Noise(Primary Dark-Current)QE
Electronic Noise
CurrentBoosterProcess
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Why Solid-State SP Micro-Detectors
Typical microelectronic advantages:
miniature size, low voltage, low power, rugged, reliable,
suitable to integration, insensitive to magnetic fields and RF, etc.
Improved basic performance:
- inherently higher Photon Detection Efficiency
over the Visible (V) and Infrared (IR) spectral range
- comparable or lower noise (dark counting rate)
- better photon timing
With respect to vacuum tube PhotoMultipliers (PMT)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Micro-Detectors: Single Photon Avalanche Diode (SPAD) Devices and electronics
SPAD Devices: Retrospect and Evolution
From Device Physics to Detector Performance
Active Quenching Circuit (AQC)
SPADs for the Infrared Spectral Range
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Current Booster Process in Micro-Detectors
Avalanche multiplication of charge carriers
by impact-ionization in reverse-biased p-n semiconductor junction
can be either exploited in
Linear amplifying mode Avalanche Photo Diodes APD
or exploited in
Trigger or Geiger Mode Single Photon Avalanche Diode
“SPAD”
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
• Bias: well ABOVE breakdown
• Geiger-mode: it’s a TRIGGER
device!!
• Gain: meaningless !!
• Bias: slightly BELOW breakdown
• Linear-mode: it’s an AMPLIFIER
• Gain: limited < 1000
Avalanche PhotoDiode Single-Photon Avalanche Diode
APD SPAD
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
SPAD Micro-Detectors: the Origin
@ Shockley Laboratory in early 60’s : Avalanche Physics Investigation
Basic insight
Model of behavior above Breakdown
Single-Photon pulses observed, but …
…application limited by device features and quenching circuit !
R.Haitz, J.Appl.Phys. 35, 1370 (1964) and 36, 3123 (1965)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
for SPAD operation
mandatory
to avoid local Breakdown, i.e.
edge breakdown guard-ring feature
microplasmas uniform area, no precipitates etc.
but for good SPAD performance.....
...further requirements!!
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Earlier Silicon Diode Structures
“Thick” SPAD“Thin” SPAD
McIntyre’s reach-through diodeHaitz’s planar diode
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
PoliMi Si-SPAD PKI* Si-SPAD (SLIKTM )
Planar epitaxial structure
typical active region:
10 to 100 µµµµm diameter
1 µµµµm thick
Reach-Trough structure
typical active region:
190 µµµµm diameter
30 µµµµm thick
*Perkin Elmer Optoelectronics
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Dark-Counting Rate (primary noise)
Generation - Recombination Centers Field-Assisted Generation
Free Carrier Generation
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Carrier Trapping and Delayed Release Afterpulsing
NB: minority carrier traps !!
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Trapping and Afterpulsing
operation @ lower temperature
lower generation rate
slower trap release
hence
primary dark-counting rate is
reduced
but afterpulsing is enhanced !!
S.Cova, A.Lacaita, G.Ripamonti, IEEE Electron.Dev.Lett. 12, 685 (1991)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Low Detector Noise
For low dark-counting rate
Reduce GR center concentration
Reduce Field-assisted generation
For low afterpulsing probability
Reduce deep level concentration (minority carrier traps)
Reduce trapping and retriggering probability
- Technology issues and device design issues
- Wide sensitive area requires efficient gettering!!
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Detection Efficiency (PDE)
Carrier Photogeneration
And
Avalanche Triggering !!
W.Oldham, P.Samuelson, P.Antognetti, IEEE Trans. Electron Devices ED-19, 1056 (1972)
higher excess bias voltage
for higher PDE !!
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Detection Efficiency (PDE)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
200 400 600 800 1000 1200
0.01
0.1
1
10
100
Qu
an
tum
eff
icie
nc
y, Q
E %
Wavelength nm
Planar SPAD PerkinElmer
C4880-21 S25 PMT
S1 PMT
PDE - Detector Comparison
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Timing
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Timing: Diffusion Tail
carrier diffusion in neutral
layer
delay to avalanche
triggering
G.Ripamonti and S.Cova, Sol. State Electronics 28, 925 (1985)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Timing: main peak width
Statistical Fluctuations in the Avalanche
Vertical Build-up (minor contribution)
Lateral Propagation (major contribution)
- via Multiplication-assisted diffusion
A. Lacaita, M.Mastrapasqua et al, APL 57, 489and El.Lett. 26, 2053 (1990)
- via Photon-assisted propagation P.P.Webb, R.J.McIntyre RCA Eng. 27-3, 96 (1982); A.Lacaita et al, APL 62, 606 (1993)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Avalanche Lateral Propagation
Photon-assisted
A. Spinelli, A. Lacaita, IEEE TED 44, 1931 (1997)
Multiplication-
assisted
higher excess bias voltage improved time-resolution
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Timing: SLIKTM reach-trough
structure
H.Dautet, ......, R.J. McIntyre and P. Webb , Appl.Opt. 32, 3894 (1993)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Timing: planar Epitaxial structure
A.Lacaita, M.Ghioni, S.Cova, Electron. Lett. Electron.Lett. 25, 841 (1989)
neutral p layer thickness w
tail lifetime ττττ = w2 / ππππ2Dn
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Timing comparison
Planar SPADPerkinElmer SPCM, SLIKTM diode
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Reach-Through SLIKTM diode
Reach-Trough structure
Typical active region:
200 µµµµm diameter
• QE: 30%@500nm; 70%@700nm • Dark Counts: 150 c/s • FWHM: > 300ps • High voltage : 300 to 400V
• High dissipation
• Delicate and degradable
• Dedicated technology, high cost
• NOT COMPATIBLE with array detectorand integrated circuits
H.Dautet et al, Appl.Opt. 32, 3894 (1994)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Planar Single Photon Avalanche Diodes
Planar structure
typical active region:
20 -100 µµµµm diameter
• Good QE and low noise
• Picosecond timing
• Low voltage : 15 to 40V
• Low power : cooling not necessary
• Standard Si substrate
• Planar fabrication process
• COMPATIBLE with array detector and integrated circuits
• Robust and reliable
• Low-cost
A.Lacaita, M.Ghioni, S.Cova, Electron.Lett. 25, 841 (1989)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
PoliMi Si SPADReach-Through Si
SPAD (SLIKTMTM )• Very good QE and low noise
• Sub-nanosecond photon timing
• High voltage : 300 to 400V
• High dissipation : Peltier cooler mandatory
• Ultra-pure high-resistivity Si substrate
• Dedicated fabrication process
NOT COMPATIBLE with array detectorand IC’s
• Delicate and degradable
• Very expensive
• SINGLE COMMERCIAL SOURCE
• Good QE and low noise
• Picosecond photon timing
• Low voltage : 15 to 40V
• Low power : cooler not necessary
• Standard Si substrate
• Planar fabrication processCOMPATIBLE with array detector
and IC’s
• Robust and rugged
• Low-cost
• NEW COMMERCIAL SOURCE
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
Active Quenching Circuit (AQC)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Passive quenching is simple...
Current Pulses
Diode Voltage
… but suffers from
long, not well defined deadtime
low max counting rate < 100kc/s
photon timing spread
et al
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Active quenching….
...provides:
short, well-defined deadtime
high counting rate > 1 Mc/s
good photon timing
standard logic output
Output Pulses
P.Antognetti, S.Cova, A.Longoni, IEEE Ispra Nucl.El.Symp. (1975), Euratom Publ. EUR 5370e
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Active Quenching Evolution
Earlier modules
in the 80’sCompact modules
in the 90’sIntegrated AQC
today
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
F.Zappa, S.Cova, M.Ghioni, US patent 6,541,752 B2, 2003
(prior. March 9, 2000)
iAQC: integrated Active Quenching Circuit
Practical advantages
Miniaturization mini-module detectors Low-Power Consumption portable modules Rugged and Reliable
Plus improved performance
Reduced Capacitance Improved Photon Timing Reduced Avalanche Charge Reduced Afterpulsing Reduced Photoemission reduced crosstalk
in arrays
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
0 40 80 120 160 200
Threshold voltage (mV)
25
75
125
0
50
100
150
Tim
e r
es
olu
tio
n F
WH
M (
ps)
Signal pick-up for improved photon-timing
Avalanche current sensing
at very low level (< 100 µA)
Can be added to any AQC
S.Cova, M.Ghioni, F.Zappa, US patent No. 6,384,663 B2, 2002
(prior. March 9, 2000)
50 µm active
area diameter
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Recent advancement
Wide active-area SPAD
100µµµµm diameter
35 ps FWHM resolution
at room temperature
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Single Photon Counting & Timing Module
Planar SPAD detector
+ iAQC
Compact and user-
friendly
Photon Detector Module
(PDM)+ Timing pick-off network
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Detector ModuleSilicon Chip
SPAD Chip and Detector Module
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Easy to use
Robust and Rugged
Low power consumption
Low cost
Less than 50ps timing resolution
Large area, up to 100µm diameter
Photon Detection efficiency, 47% @ 532nm, 5V overvoltage
www.micro-photon-devices.com
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Comparison of Technology
MPD’s photon counting module offer the best performance
when fast timing resolution is required.
MPD’s technology provides Superior detection efficiency from 400 to 600nm
Parameter SPAD & AQ circuit
(MPD Technology)
Integrated SPAD &
passive quench
Reach-Through SPAD Units
Detector Diameter 20 to 100 20 to 50 200 µmPhoton Detection Efficiencies@ 400nm@ 532nm
@ 650nm
25
4735
18
35 25
5
4065
%
Dark Counts20um50um
100um
250 typ (uncooled)
100 max (cooled)1000 max (cooled)
50 max (cooled)
200 max (cooled)NA <100
cps
Timing Resolution <50 40 300 - 600 psAfter Pulsing 0.5 typ, 1.5 max 3 max 0.5 typ %
Max Continuous Counting Rate 15 11,5 15 Mcps
Array development
Monolithic arrays possible,
60 element array demonstrated. Limited to 100-200 pixel
arrays.
Monolithic arrays possible. Large area arrays possible
with small pixels - TBD.
Monolithic arrays not possible
Technology Comparison
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
SPADs for the Infrared Spectral Range
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Germanium SPAD devices
Similar to silicon devices, but
deep cooling mandatory (liquid nitrogen and lower)
absorption edge shifts below 1500nm @ low
temperature
strong trapping effects
strong field-assisted generation effects
static situation of technology
A.Lacaita, P.A.Francese, F.Zappa, S.Cova, Appl.Opt. 33, 6902 (1994)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
InGaAs-InP SPAD devices
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Photon Counting @ 1550nm
Detection Efficiency vs. Overvoltage
@ various temperatures
Data obtained using Princeton Lightwave InGaAs SPADs
Dark counting rate vs. temperature
@ various overvoltages Dark counting rate vs. hold-off
time @ various temperatures
Timing Resolution
0.0 0.5 1.0 1.5 2.0 2.5 3.00
1x103
2x103
3x103
4x103
5x103
6x103
7x103
FWHM=65ps
Co
un
ts (
cp
s)
Time [ns]
T = 200 K
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
InGaAs-InP SPAD devices
Complex device structure with heterojunctions
Moderately deep cooling required (up to about 220K)
Strong field-assisted generation effects
Very strong trapping effects with very long release time
Free-running operation with long deadtime (> 100micros)
In practice limited to fast-gated operation
Technology in evolution
A.Lacaita, F.Zappa, S.Cova, P.Lovati, Appl.Opt. 35, 2986 (1996)
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
Application Cases
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Microsystems for Genetic Analysis
Single Molecule Spectroscopy
Adaptive Optic Systems
Non-Invasive Testing of ULSI Circuits
Quantum Cryptography (QKD)
Outline
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Microsystems for DNA analysis
Current trend
• system miniaturization
• minimal sample quantity
• low cost of operation
Ultra high sensitivityrequired to the detector
Valid for both Capillary Electrophoresis (CE)separation
and Microarrays of DNA and Proteins
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Capillary Electrophoresis (CE) for DNA fragment
separation and analysis
DNA Fragment separation
Electropherogram
Time (min)
Inte
ns
ity (
a.u
.)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Micro-Chip Electrophoresis (MCE)
Injection Separation
8 cm
laser
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Looking inside the MCE apparatus...
• Compact & low-cost set-up with:
• Fully automated operation
• Laser diode excitation of fluorescence
• Controlled chip temperature
• Dual wavelength detection
• Dual HV power supply (0-5kV)
• Confocal optical scheme
• Remote control
• Problem debug via internet
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
.....with a closer look to the Micro-Chip Holder
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
DNA fragment separation: MCE vs CE
Separation of DNA
fragments
micro-sample
in MCE set-up
(100 s time scale)
Separation of DNA
fragments
macroscopic sample
in ordinary CE set-up
(50 min time scale)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Sensitivity attained in MCE
12141
6181101
121141161
181
0
10000
20000
30000
40000
50000
60000
70000
80000
Static measure5ng/ul
0,5ng/ul
0,05ng/ul
100pM oligonucleotide label led with CY 5
300
400
500
600
700
800
900
1000
1100
1200
1300
0 50 100 150 200Time [Sec.]
Co
un
ts [
c/s
]
S/N=35
CE Separation in glass microchip
run buffer: TAPS-TRIS 100mM pH 8.5.
Sample : 23 mer oligonucleotide labelled with CY 5
Detection limit @ S/N=3 : 1pM
corresponds to < 30 molecules in the injection volume of
50pL
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
“An array is an orderly arrangement of probes with known identity
which are used to determine complementary targets”
Microarrays
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
DNA Microarrays vs Protein Microarrays
DNA Microarrays:
Very High number of spots > 10000
Sample Amplification by PCR
Protein Microarrays:
Moderate number of spots < 100
NO sample Amplification
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
SPAD Matrix Detector
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
High-Sensitivity Parallel Detection
Basic goals - reduction of the acquisition time
- miniaturization, lower system cost
Photon Counting in
Parallel FCS measurements in life sciences
Single photon spectroscopy
Adaptive optics in astronomy
Photon Timing in
Fluorescence lifetime imaging
3-D imaging with millimeter resolution
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
6x8 SPAD Matrix Detector
50 µm pixel diameter
240 µm pitch
4 interleaved sectors including 12 pixels
with common anode
sector 1
sector 2
sector 3
sector 4
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Single pixel addressing
12 AQCs in parallel
20 bit counters
Peltier cooling
with digital temperature control
Single bias supply (5V)
Remote Full Control
through USB port
2-D photon counting module
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Size 20cm x 8cm x 4cm
2-D photon counting module
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
Single Molecule Spectroscopy
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Single Molecule Spectroscopy
Measurement on Measurement on singlesingle molecules, molecules, not ensemble not ensemble averageaverage
RealReal--timetime measurement of molecule evolution measurement of molecule evolution
Informations on the molecule Informations on the molecule dynamicsdynamics
Focus on molecules of biological interest : proteinsFocus on molecules of biological interest : proteins
FRET : Fluorescence Resonance Energy Transfer
Nano-scale structural changes in single protein molecules
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Idea of Sunney Xie and Haw Yang* (Harvard University): to probe Single-Molecule Protein Dynamics by a correlation analysis of fluctuations
in real time of fluorescent photon delay with respect to laser excitation
* H. Yang, G. Luo, P. Karnchanaphanurach, T.M. Louie, I. Rech, S.Cova, L. Xun, and X. Sunney Xie, SCIENCE ( 2003)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Single Photon Timing Module SPTM
Compact (82x60x30mm)
Single power supply (+15V)
Controlled Temperature
(Peltier cell)
Software controlled settings
On-board fast counters
RS-232 data transmission
I.Rech et al., IEEE J. of Sel. Topics in Quantum Electronics, vol.10, 788 (2004)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
SPTM performance in the Harvard set-up
Instrumental Response Function (IRF)
with SPTM and with PerkinElmer SPCM
Time-resolution: 60ps
Dark Counts: down to 5 c/s
Quantum Efficiency: 45% @
500nm
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Single Molecule Fluorescent Decay
Single Fre–FAD complex
measured with SPTM (line).
with PerkinElmer SPCM (circles)
the shortest lifetime components
are not resolved
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
Adaptive Optics Systems
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
STRAP = System for Tip-tilt Removal with Avalanche Photodiodes
collaboration: ESO - Microgate - PoliMi
STRAP Adaptive-Optics System of the VLT Observatory (Chile) European Southern Observatory - ESO
D.Bonaccini et al,
Proc. SPIE Vol. 3126, p. 580-588,
Adaptive Optics and
Applications; R.K.Tyson, R.Q.Fugate
Eds., 1997
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Hybrid Quad- SPAD detector
4 SPAD PerkinElmer SLIK®
4 hybrid AQC
4 E2PROMPeltier
Spacer Ceramic
Centering Ceramic
2x2 lenslet array
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
STRAP – compatible
geometry
100µm, 80µm, 50µm
pixel diameter
New development: Monolithic Quad-
SPAD detector
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
New development: SPADA Wavefront
Sensor
SPADA: Single Photon Avalanche Diode Array
collaboration
PoliMi, IMM-CNR Bologna, UniPisa, Osservatorio di Catania, ESO
F. Zappa, S.Tisa, P.Maccagnani, D.Bonaccini Calia, G.Bonanno, R.Saletti
"Pushing Technologies: Single Photon Avalanche Diode Arrays"
Proc. SPIE Vol. 5490, p. 1200-1210, Advancements in Adaptive Optics;
D. Bonaccini Calia, B.L. Ellerbroek, R. Ragazzoni Ed.s, 2004
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
SPADA Chip Layout
20µm
35µm50µm
75µm
60 element array with circular geometry
plug-in compatible with MACAO
4 sets of pixels
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
SPADA detector head
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
SPADA Opto-Mechanical System
WaveFront
microspheres held by ceramic holder
SPADA sensor
Peltier cooling stage
microlenses array
HeptagonMACAO lenslet array
No fibre coupling: higher reliability, lower losses, ruggedness, compatibility
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
SPADA system for AT
MACAO equipment
(by ESO)
power
supplyMains (230V ac)
re mote
Computer
Detection Board
Top metalic plate
SPADA
RS
23
2
2
SC
SI
cab
les
(68
wir
es
eac
h)
Po
we
r su
pp
ly c
ab
le(7
wir
es)
Gat
e
Inte
rlo
ck
US
B
Seamless compatible with ESO MACAO sensor
(electronics & optomechanical interfaces designed for CALDO and originally for AT-MACAO)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Detection board
iAQC diff.out
iAQC diff.out
iAQC diff.out
iAQC diff.out
SC
SI
connecto
r6
8 p
inS
CS
I con
necto
r68 p
in
1
2
3
60
PeltierController
Pelt
ier
e T
erm
oR
µC
gate
interlock
RS232
USB
Gate In
SMCdiff.
Detection electronic board
gate
Vhigh
T.meas
T.set
Common anode
supply
fro
m t
he
SP
AD
A s
enso
r
to D
ata-
Pro
ces
ing
Ele
ctro
nic
s o
r to
MA
CA
O e
qui
pm
ent
Interlock
SMCdiff.
gate
inter lock
hold-off
duration
overvoltage
setting
to remote computer
of MACAO equipment
to Data-Processing boarddriver
Pow
er s
up
pli
es +5V
+12V
-24V
gnd
+12VPeltier
gndPeltier
Linear
regulator
-10V...-24V
Operates the 60 SPADs
through 60 iAQCs
Outputs 60 channels
differential lines directly to MACAO
Controls SPADA settings
temperature, overvoltage, hold-off, gating
Controls gates & interlocks
Sends data directly to MACAO
Sends data to Processing Board for stand-alone operation
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
AO Curvature Sensor and LGS layer
sensing mode
Enable
SC
SI
connecto
r68 p
inS
CS
I connecto
r68
pin
fro
m D
ata
-Pro
cesi
ng
Ele
ctro
nic
s
Data BusData shift
clock
Audioampl.
Membrane
Load 4Ω 4W
Output
GNDSin. OutLEMO
Sine
Generator16bit sine table
8 bit sine peak
FireWire
FireWire for settings downloading
for dat a uploading
RS232 to Detection boarddriver
Pow
er
sup
plies+5V
+12V-24Vgnd
+12VPeltier
gndPeltier
to D
etec
tion
bo
ard
Power-supply forDetection board
Mains 230V acPower-supply for
Data-Processing board
diff.Gate InSMC
diff.Gate Out
SMC
diff.InterlockIn SMC
from AO equipment
to Detection board
diff.InterlockOut SMC
from AO equipment
to Detection board
Timingand
control logic
diff.LaserSynch
In SMC
diff.LaserSynchOut SMC
from AO equipment
to AO equipment
1st
A counter
Ck
Enable
ShiftRegister
1st
B counter
Ck
Enable
Processing:A-B
A+B
CurvatureWaveFrontSensor
Local Mode Operation
On Board Curvature
Signal computation
possible
3 km vertical resolution
Sine wave generation
for membrane mirror
In/Out
Synchronizations with
pulsed laser
Fast FireWire uploading
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Fast Transient Phenomena
1st Counter LatchCk
Enable
Timing and control logic
Mains 230V ac
SC
SI
con
ne
cto
r6
8 p
inS
CS
I c
on
nect
or
68
pin
Ck
Shift
Register
diff.Gate In
SMC
diff.Gate Out
SMC
diff.Interlock
In SMC
from
Dat
a-P
roce
sing
Ele
ctro
nic
s
FireWire
60th Counter LatchCk
Enable Ck
Shift
Register
Enable Data Bus
Data shift
clock
FireWire for settings downloading
for data uploading
from AO equipment
to Detection board
diff.Interlock
Out SMCfrom AO equipment
to Detection boardRS232 to Detection boarddriver
Po
we
r su
pp
lie
s
+5V
+12V
-24V
gnd
+12VPeltier
gndPeltier
to D
etec
tion
bo
ard
Power-supply for
Data-Processing board
Power-supply forDetection board
Time slots: 10µs-100ms
Measurement time:
Time Windows:
No blind-slots
Fast FireWire
uploading
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Experiment done at
20 kframe/s
Pixels are illuminated by
1ms-period saw-tooth modulated light
Fast Transient Imaging
10µsec-100msec i.t.
Time tagging
Continuos streaming
Firewire link
12 bit data
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
Non-Invasive Testing of ULSI Circuits
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Spontaneous Photon Emission in MOSFET
Photon Emission
High Electric Field
n+p+
p
DS
Gox
Bulk SourceGate
Drainhν
hot-carriers
Impact Ionization(Substrate current)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Light emission from CMOS inverters
4.4 4.5 4.6 4.7 4.8 4.9 5.00
1
2
3
4
5
ISN
PH
VIN
VOUT
Arb
itra
ry U
nit
s
Time [ns]
VIN VOUT
VDD
p-FET
n-FET
ph
IS
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Non-invasive Testing of Integrated Circuits
SPAD
Inputobjective
Imagingdetector
Focusingobjective
hνννν
6 8 10 12 14 16 18 20 220
20
40
60
80
100
120
140
160
180
2 ns
Ph
oto
n C
ou
nts
(a
.u.)
Time [ns]
Clock IN
Data Out
1.9 ns
(Timing detector)
locates emitting MOSFETs
marks arrival timeof single photons
Photons emitted by MOSFET
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
-0.1 0.0 0.1 0.2 0.3 0.40
20
40
60
80
100
120
FWHM = 50ps
Cou
nts
(a
.u.)
Time [ns]
Single-Inverter transition
FWHM=250ps
J.C. Tsang et al., APL 70, 889 (1997)
Measured with SPAD Measured with PMT
F. Stellari et al, IEEE TED 48, 2830 (2001)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Test example on a real circuit
p-FET
n-FET
2.0 2.5 3.0 3.5 4.0 4.50
200
400
600
800
1000
1200
1400
pFET
28.3ps
Ph
oto
n c
ou
nts
(a.u
.)
Time [ns]
nFET
Laser ScanningLaser ScanningMicroscope (LSM)Microscope (LSM)
Transistor localization on the schematic … … and on the layout (LSM image)
Spontaneous luminescence pulses
synchronous with
MOSFET switching
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Example of defect localization by
measuring dynamic waveforms
Faulty Inverter
5 10 15 200
10
20
30
40
50
Ph
oto
n c
ou
nts
(a.u
.)Time [ns]
5 10 15 200
10
20
30
40
50
Ph
oto
n c
ou
nts
(a.u
.)
Time [ns]
Good Inverter
Faulty Inverter
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Spatial Resolution
5x50x
microscope objectives
single inverter many inverters
“teleobjective” “wide angle”
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
ECL comparator
Electronics1 2 46 47
ring oscillator
1kΩ
counter
on-chp device
÷32
Fast Ring Oscillator
50x
0 50 100 150 200 250 300 350 400 4500
500
1000
1500
2000
2500
cycle-time
321
Cou
nts
(a
.u.)
Time [ns]
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
Quantum Cryptography (QKD)
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Quantum Key Distribution (QKD) principle
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
QKD system in free space transmission
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
QKD system in fibre transmission
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Conclusions and Prospect - 1
SPADs in planar epitaxial Silicon technology offer high performance at low-cost;
further improvements are under way (wider area SPAD; array detectors...)
Monolithic iAQCs open the way to miniaturized modules (down to the chip scale)
Remarkable results obtained in diversified applications: DNA and Protein Analysis;
Single-Molecule Spectroscopy; Wavefront Sensors in Adaptive Optics; etc.
The technology for infrared-sensitive SPAD devices is in evolution:
significant progress may be expected in the near future
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Conclusions and Prospect - 2
Results of decades of research made widely available by
a new spinoff company
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
PoliMi Staff 2005
COVA, S. Full Professor
GHIONI, M. Full Professor
ZAPPA, F. Associate Professor
RECH, I. Assistant Professor
LABANCA, I. Research Associate
GALLIVANONI, A. Research Associate
TOSI, A. Post-Doc
TISA, S. Ph.D. Student
RESTELLI, A. Ph.D. Student
GULINATTI, A. Ph.D. Student
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Acknowledgments
IMM-CNR, Bologna (I) - P. Maccagnani, A. Poggi, S. Solmi, M. Severi
ICRM-CNR, Milano (I) - M. Chiari, M. Cretich
ESO (D) – D. Bonaccini Calia
MICROGATE, Bolzano (I) - R. Biasi, A. Giudice
HARVARD University (MA, USA) - X. Sunney Xie, H. Yang, G. Luo
IBM Central Research (NY, USA) - J.C. Tsang, M. Mc Manus
Heriot Watt Uni (UK) - G. Buller, S. Pellegrini, K. Gordon, V. Fernandez
Micro Photon Devices, Via Stradivari 4, 39100 Bolzano, Italy, www.micro-photon-devices.com
MPDCompany Overview
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Vision and Markets
Build a business that is the leader in Photon Counting Technologies by:
Providing quality and reliable modules at a reasonable price.
Attention to customer requirements
Further developing the technology: ie: APD
arrays, Higher efficiency in the red, 1550nm
detection, APD+ASIC processing and tube technology.
Markets Served: Universities, R&D facilities, Small OEM’s
Astronomy – Adaptive Optics
Biomedical – DNA and Drug discovery, Confocal Microscopes, Particle Sizing.
Quantum Cryptography – InGaAs APD
Custom applications
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
MPD Company Overview
21 employees (with parent company Microgate Srl)
1350 square meters of area
ISO certification in progress
Close collaboration with state-of-the-art Silicon foundry
Electronic workshop Class 10000 clean room
for integration
Inventory and Production
management
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Silicon Foundry Overview
Permanent Staff: 49
Short Term Staff: 5
Associated Researchers: 30
Class 100 clean area (250 square meters)
Pilot line for fabrication of devices and IC’s in 4” silicon wafer
• Technological processes with high flexibility
• Consolidated know-how in Si device technology
• Si-micromachining and Si anodization
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Management and Technical Team
Roberto Biasi, CEO Micro-Photon-DevicePhD in Aerospace Engineering at Politecnico di Milano in 1995. As founder and active partner of Microgate S.r.l., he has been involved as reaserch engineer and project manager in several leading projects in adaptive optics and telescope design, like MMT and LBT adaptive secondaries, ALMA antenna control system and STRAP, a tip-tilt adaptive optics control system based on Single Photon Avalanche Diodes. With this project he entered the field of photon counting and established a collaboration with the research team leaded by Prof.Cova at Politecnico di Milano. This collaboration brought to the foundation of Micro Photon Devices, a spin-off company specialized in production of single photon counting modules.
Sergio Cova, CTO Micro-Photon-Device, FounderBorn in 1938, doctor degree in Nuclear Engineering in 1962 at Politecnico di Milano, Italy, where he is Full Professor of Electronics since 1976. Fellow of the IEEE. Author of over a hundred and seventy papers in international refereed journals and conferences and of four international patents (US and Europe). He has given innovative contributions to research and development of photon detectors and associated electronics, nuclear electronics, microelectronic devices and circuits, electronic and optoelectronic measurement instrumentation and systems. He pioneered the development of Single-Photon Avalanche Diodes SPAD; he invented the Active-Quenching Circuit AQC, which opened the way to their application, and developed it up to monolithic integrated form; he devised and experimented new SPAD devices in silicon and in germanium and III-V semiconductors, thus pioneering the extension of photon counting techniques to the infrared spectral range. He collaborated to interdisciplinary research in physics, astronomy, cytology and DNA and protein analysis, developing dedicated electronic and optoelectronic devices and instrumentation.
Massimo Ghioni, Technical Advisor, FounderBorn in 1962, doctor degree in Nuclear Engineering in 1987 at Politecnico di Milano, Italy, where he is Full Professor of Electronics since 2000. He designed and experimented in his thesis work the first silicon Single-Photon Avalanche Diodes SPAD devices with epitaxial structure, demonstrating their picosecond photon timing performance. Visiting scientist in 1992 at the IBM T.J. Watson Research Center, Yorktown Heights, NY, USA, he developed a new CMOS compatible SOI photodetector for optical datacom applications. His current research interests are focused on the development of SPAD detectors and associated electronics for new microanalytical techniques in biomedical, genetic and diagnostic applications. He has worked in several leading research programs in international collaboration with universities, public bodies and high technology industries, such as Harvard University, USA; Heriot-Watt University, UK; ESO European Southern Observatory; Carl Zeiss, Jena, Germany; IBH, Glasgow, UK; Edinburgh Instruments, UK. He has published over eighty papers in international peer-reviewed journals and proceedings of international conferences and he is co-author of six US and European patents.
Franco Zappa, Technical Advisor, FounderBorn in 1965. Ph.D. in Electronics and Communications in 1993 at Politecnico di Milano, Italy, where he is Associate Professor of Electronics since 1998. His research interests are the design of single-photon avalanche photodiodes and related electronics for visible and near-infrared wavelength ranges, the design of photodetector arrays for imaging, and the non-invasive testing of VLSI circuits exploiting spontaneous hot-carrier luminescence emission. In 1994 he pioneered the first monolithic electronics for single-photon detection, designing the first integrated prototype ever reported in literature. He has published over sixty papers in international peer-reviewed journals and proceedings of international conferences and he is co-author of three US and European patents.
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Product Portfolio
Single photon counting modules with ultra-fast timing resolution and high photon detection efficiency.
Active Quenching module which can be used with other SPAD’s, for instance:InGaAs, HgCdTe and Silicon devices
Custom modules and arrays can be developed using MPD’s proprietary silicon SPAD devices and iAQC circuits
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
MPD has a solid understanding of Photon MPD has a solid understanding of Photon
Counting. Sergio Counting. Sergio CovaCova and his team have and his team have
been working on Photon Counting for over been working on Photon Counting for over
25 years, and have developed leading IP in 25 years, and have developed leading IP in
active quenching and SPAD technology.active quenching and SPAD technology.
MPD has developed a strong relationship MPD has developed a strong relationship
with a statewith a state--ofof--art Silicon Foundry. art Silicon Foundry.
This will ensure a steady supply of SPADThis will ensure a steady supply of SPAD’’s, s,
and continuous improvements in SPAD and continuous improvements in SPAD
performance.performance.
MPD has the infrastructure to be a solid MPD has the infrastructure to be a solid
OEM supplier OEM supplier –– and work closely with itand work closely with it’’s s
customers to develop custom solutionscustomers to develop custom solutions
Summary of Capabilities
PoliMi - Politecnico di Milano, DEI IEEE - LEOS DL 2005
Thank-youQuestions?
See us atPhotonics West
Booth # 5115
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