1. (Status in) Silicon Photomultiplier developments
9/12/2018
(Status in) Silicon Photomultiplier developments
Jelena Ninkovic MPG Halbleiterlabor
Some properties and state of the art of SiPMs
SiPM development at MPS Semiconductor Laboratory
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München
Ladislav Andricek, MPI Munich

2. Avalanche PhotoDiode - APD
An avalanche photodiode (APD) is a photodiode that internally amplifies the photocurrent by an avalanche process. p+ n+
Metal contact
n type bulk (n-) l o g ( G a i n )
Reverse Bias Voltage
Geiger
mode
Linear
no gain
Linear/ Proportional mode
Bias: slightly BELOW breakdown
Linear-mode: it’s an AMPLIFIER
Gain: limited < 300 (1000)
High temperature/bias dependence
No single photo electron resolution
Geiger mode
Bias: (10%-20%) ABOVE breakdown voltage
Geiger-mode: it’s a BINARY device!!
Count rate limited
Gain: “infinite” !!
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

3. The Silicon Photomultiplier
9/12/2018
The Silicon Photomultiplier
An avalanche photodiode (APD) in Geiger mode is a highly efficient single photon counting device
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München
Ladislav Andricek, MPI Munich

4. The Silicon Photomultiplier
9/12/2018
The Silicon Photomultiplier
An avalanche photodiode (APD) in Geiger mode is a highly efficient single photon counting device
BUT:
Output signal of a single Geiger APD is independent of number of incident photons
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München
Ladislav Andricek, MPI Munich

5. The Silicon Photomultiplier
9/12/2018
The Silicon Photomultiplier
An avalanche photodiode (APD) in Geiger mode is a highly efficient single photon counting device
BUT:
Output signal of a single Geiger APD is independent of number of incident photons
Solution:
Combine an array of small Geiger APDs onto the same substrate and connect all cells in parallel
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München
Ladislav Andricek, MPI Munich

6. The Silicon Photomultiplier
9/12/2018
The Silicon Photomultiplier
An avalanche photodiode (APD) in Geiger mode is a highly efficient single photon counting device
BUT:
Output signal of a single Geiger APD is independent of number of incident photons
Solution:
Combine an array of small Geiger APDs onto the same substrate and connect all cells in parallel
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München
Ladislav Andricek, MPI Munich

7. What is available
MEPhI/Pulsar (Moscow) - Dolgoshein CPTA (Moscow) - Golovin Zecotek(Singapore) - Sadygov Amplification Technologies (Orlando, USA) Hamamatsu Photonics (Hamamatsu, Japan) SensL(Cork, Ireland) AdvanSiD (former FBK-irst Trento, Italy) STMicroelectronics (Italy) KETEK (Munich) RMD (Boston, USA) ExcelitasTechnologies (former PerkinElmer) MPS Semiconductor Laboratory (Munich) Novel Device Laboratory (Beijing, China) Philips (Netherlands) …. ……Every producer uses its own name for this type of device: MRS APD, MAPD, SiPM, SSPM, MPPC, SPM, DAPD, PPD, SiMPl , dSiPM…
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

8. Gain
The gain is in the range of 105 to 107. Single photoelectrons produce a signal of several mV on a 50 W load.
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

9. DCR of most recent devices  few 10 kHz/mm²
Dark count rates (DCR)
Average frequency of the thermally generated avalanches breakdown process that result in a current pulse indistinguishable from a pulse produced by the detection of a photon.
Few 100kHz/mm² < DCR < 1 MHz/mm² till room temperature
DCR of most recent devices  few 10 kHz/mm²
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

10. Optical Crosstalk (OCT)
A. Lacaita, et al., IEEE Trans. Electron Devices ED-40 (1993) 577
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

11. Optical cross talk suppression
Optical barrier trench
light
Second pn junction
1: without optical crosstalk suppression
2: suppression by optical barrier
3: suppression by optical barrier and second pn-junction
Buzhan et al., NIM A 610 (2009)
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

12. Optical cross talk 8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

13. Most of the devices are below 10%
Afterpulsing
carriers can be trapped during the avalanche discharge and then released  trigger a new avalanche during a period of several 100 ns after the initial breakdown
MPPC
Most of the devices are below 10%
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

14. Photon Detection Efficiency
PDE = Fill Factor * QE * Geiger probability
Main limitations:
Geometrical occupancy of the Geiger diodes (max 80%)
Reflection losses on the SiPM surface (<10% possible)
Can be tuned by coating
λmin determined by thickness and quality of surface implantation
λmax determined by thickness of active volume
Breakdown Initiation Probability (~90%)
Function of the electric field in the avalanche region
End up with 50…60% PDE
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

15. Fill factor - Photoemission image
MPPCs
Old (2007) MEPHI device 42mm pitch size
SENSL
FF ~ 20-80%
CMOS devices have lower
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

16. in the blue region: 35 – 60 % in the green region : 25 – 50 %
PDE
MPPC brochure
in the blue region: 35 – 60 % in the green region : 25 – 50 %
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

17. PDE - NUV sensor size: 12×12mm² (cell size = 50 μm
PDE (175 nm) = 17 % (best sample)
Gain  165 K
DCR = 165 K
decay time  ns
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

18. single photoelectron time resolution (SPTR)
Timing
Avalanche breakdown process is fast and the signal amplitude is big. very good timing properties even for single photons.
Fluctuations in the avalanche are mainly due to a lateral spreading (~10 ps) by diffusion and by the photons emitted in the avalanche.
A. Lacaita et al., Apl. Phys. Letters 62 (1992) A. Lacaita et al., Apl. Phys. Letters 57 (1990)
single photoelectron time resolution (SPTR)
40 ps < SPTR (σ) < 60 ps
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

19. Recovery time 8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

20. Current R&D
Understanding and improving the radiation tolerance of SiPMs
Large dynamic range: Hamamatsu R&D down to 10mm pitch
Lowering of dark rate : all
Increasing PDE at and lower 400nm : all
Large area SiPMs : SiPMs with Area ≥ 3x3 mm2 produced by many companies: Hamamatsu, CPTA, Pulsar, Zecotek, SensL, FBK, STMicro…
SiPM Arrays  further increase of sensitive area
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

21. Non conventional SiPM developments
MAPDs from Zecotek
SiMPl – MPS Semiconductor Lab
dSiPMs from Philips
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

22. MPG semiconductor laboratory
1000m2 clean room up to class inch silicon process line with custom made equipment
design and simulation tools testing & qualification mounting capabilities
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

23. Bulk resistor type - SiMPl approach
high field AD RQ CD CC
Vbias p+ n
n- non-depleted region
n- depleted gap region n+
Sensor wafer
Handle wafer
SOI wafers
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

24. SiMPl : Advantages and Disadvantages
no need of polysilicon
free entrance window for light, no metal necessary within the array
Smaller parasitic capacitance
coarse lithographic level
simple technology
inherent diffusion barrier against minorities in the bulk  less optical cross talk
Drawbacks:
required depth for vertical resistors does not match wafer thickness
wafer bonding is necessary for big pixel sizes
significant changes of cell size requires change of the material
vertical ‘resistor‘ is a JFET  parabolic IV  longer recovery times
Jelena Ninkovic
SLAC, July 2014

25. Prototype production High linearity!
High homogeneity over big distances! cells arrays placed over 6mm distance
High linearity!
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

26. Detection of particles
- High gain in the sensor
- Excellent time stamping due to avalanche process (sub-ns)
- Minimum ionizing particles generate about 80 e-h-pairs/µm
- No need for high trigger efficiency
80e-h-pairs/um ist fraglich
Reduction of dark rate and cross talk by order of magnitude
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

27. Next generation SiMPl devices - DSiPMl – collaboration with DESY
Ultra fast particle tracker - High energy physics application
MPG HLL:
Topologically flat surface
High fill factor
Adjustable resistor value
Low RC -> very fast
Single pixel readout
Position sensitivity
DESY:
Active recharge
Ability to turn off noisy pixels
Fast timing
Pitch limited by the bump bonding
Position resolving signal processing
Individual cell electronics, Logic, TDC, Photon counter
Ultra fast single photon sensitive imager – Photon science +
Individual cell electronics, Logic, TDC, Photon counter
Possible applications:
Future trackers at colliders
Detectors for hadron therapies
X ray detectors
PET detectors
Adaptive optic sensors
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

28. Summary SiPMs have capacity to replace PMTs in many applications.
Optimization of properties can be/must be done for every application.
Experiments already using SiPMs:
T2K ND280 – SiPMs in the experiment
Calice Hadronic calorimeter – 8000 SiPMs
FACT – small camera with 1440 SiPMs …
studies for Belle II particle ID upgrade
studies for CMS outer Hadron Calorimeter upgrade
Medical applications are driving a lot of developments
 Goal to have PET-MR scanner …
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München

29. Thanks for your attention!!!
8th Terascale Detector Workshop 2015
Jelena Ninkovic, MPG HLL, München