0. Performance of the latest prototypes of NUV-HD Silicon Photomultipliers
G. Zappalà, F. Acerbi, A. Ferri, A. Gola, G. Paternoster, V. Regazzoni, N. Zorzi, C. Piemonte

1. G. Zappala’ – Vienna Conference on Instrumentation 2016
Outline
FBK Technology roadmap to HD
Characterisation methods
Characterisation results of NUV-HD
Results in relevant applications
Preliminary on NUV-HD low cross-talk
Conclusions
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

2. G. Zappala’ – Vienna Conference on Instrumentation 2016
Outline
FBK Technology roadmap to HD
Characterisation methods
Characterisation results of NUV-HD
Results in relevant applications
Preliminary on NUV-HD low cross-talk
Conclusions
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

3. Near-UV FBK SiPM roadmap
NUV
Cell pitch 40 µm
60 % Fill Factor
New Substrate
NUV Low-AP
(F. Acerbi et. al., NUV Silicon Photomultipliers With High Detection Efficiency and Reduced Delayed Correlated-Noise, IEEE T. Nucl. Sci., Vol. 62, n.3, 2015)
NUV-HD
New cell border
(trenches)
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

4. High-Density technology in NUV
NUV-HD SiPM
Trench
< 2 µm
High-field region
Poly strip resistor
Metal
Cell 2
Cell 1
~ 4.5 µm
NUV-SiPM
Cell 3
NUV High-Density (HD) technology: Lower dead border region → Higher Fill Factor Trenches between cells → Lower Cross-Talk
(C. Piemonte et. al., (2016) IEEE T. Electr. Dev., /TED )
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

5. Fill Factor in HD technology
Cell Pitch L
The HD 15 µm pitch is equivalent to the standard 40 µm
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

6. NUV-HD SiPM layout features
High PDE
Cell Pitch
15 µm
20 µm
Fill Factor (%) 55 66
#cells/mm2
~ 4444
2500
25 µm
30 µm
35 µm
40 µm 73 77 81 83
1600
~ 1111
~ 816
625
High Dynamic Range
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

7. G. Zappala’ – Vienna Conference on Instrumentation 2016
Outline
FBK Technology roadmap to HD
Characterisation methods
Characterisation results of NUV-HD
Results in relevant applications
Preliminary on NUV-HD low cross-talk
Conclusions
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

8. G. Zappala’ – Vienna Conference on Instrumentation 2016
PDE Setup
SiPM
Amplifier board
Reference Photod.
LED
Waveform generator
Integrating sphere
Pulsed LEDs (UV – NIR) used as light sources
Reference Photodiode to monitor the stability of light at SiPM location
Amplified signal is acquired by the oscilloscope, synchronised with waveform generator
Developed LabVIEW Software used to analyse the signals
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

9. G. Zappala’ – Vienna Conference on Instrumentation 2016
PDE Analysis
Pulses integration
Analysis of the charge histogram to know the probability of “No detection” P0
𝑷𝑫𝑬= − 𝒍𝒏 𝑷 𝟎 𝑰𝒎𝒑𝒊𝒏𝒈𝒊𝒏𝒈 𝑷𝒉𝒐𝒕𝒐𝒏𝒔
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

10. G. Zappala’ – Vienna Conference on Instrumentation 2016
Dark Measurements
SiPM
Thermostatic Chamber
Amplifier board
Output signal acquired by oscilloscope
Pulses identification
Scatter plot of Amplitude vs. inter-times
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

11. G. Zappala’ – Vienna Conference on Instrumentation 2016
Dark Analysis
Direct CT
Primary AP
Delayed CT
(C. Piemonte et. al., (2012) IEEE NSS/MIC Conf. Rec., N1-206)
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

12. G. Zappala’ – Vienna Conference on Instrumentation 2016
Outline
FBK Technology roadmap to HD
Characterisation methods
Characterisation results of NUV-HD
Results in relevant applications
Preliminary on NUV-HD low cross-talk
Conclusions
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

13. NUV-HD electrical parameters
Gain > 1e6
25µm
30µm
35µm
40µm
Rq ~ 1.5 MΩ to allow extended operational range
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

14. G. Zappala’ – Vienna Conference on Instrumentation 2016
PDE at peak
PDE at 400nm, T ~ 25°C , 1x1mm2 SiPM
25µm
30µm
35µm
40µm
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

15. T ~25°C, 1x1mm2 SiPM, 30µm Cell Pitch, 10V overvoltage
PDE Spectrum
T ~25°C, 1x1mm2 SiPM, 30µm Cell Pitch, 10V overvoltage
PDE > 40% from 300 to 480nm
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

16. Dark Noise Dark count rate vs PDE at 400 nm 25µm 30µm 35µm 40µm
DCR fluctuates around these typical values
DCR < 100 kHz up to the higher PDE in all cases
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

17. G. Zappala’ – Vienna Conference on Instrumentation 2016
Correlated Noise
PDE at 400 nm
CT = 10%, PDE > 40%
25µm
30µm
35µm
40µm
25µm
30µm
35µm
40µm
Delayed Noise < 2%
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

18. G. Zappala’ – Vienna Conference on Instrumentation 2016
Outline
FBK Technology roadmap to HD
Characterisation methods
Characterisation results of NUV-HD
Results in relevant applications
Preliminary on NUV-HD low cross-talk
Conclusions
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

19. 4x4mm2 SiPM, LYSO Crystal 3x3x5mm3, T = 20°C
NUV-HD in PET
4x4mm2 SiPM, LYSO Crystal 3x3x5mm3, T = 20°C
25µm
30µm
35µm
40µm
(See S. Gundacker’s talk on 18/02/2016, medical applications session)
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

20. NUV-HD for Cherenkov detection
NUV-HD 30µm Cell Pitch PDE, 10V OV
Cherenkov light spectrum in Earth’s atmosphere
(See D. Simone’s poster, Poster Session B, #Board 99)
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

21. NUV-HD at Cryogenic temperature
A low-electric field NUV-HD version has been developed to reduce
the tunnelling component of the DCR.
> 7 orders of magnitude !
Standard field
Low-field
A 10x10 cm2 SiPM array would have a total DCR < 100 Hz!
(See C. Savarese’s poster, Poster Session A, #Board 96)
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

22. G. Zappala’ – Vienna Conference on Instrumentation 2016
Outline
FBK Technology roadmap to HD
Characterisation methods
Characterisation results of NUV-HD
Results in relevant applications
Preliminary on NUV-HD low cross-talk
Conclusions
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

23. Low Cross-Talk technology
Presented at NSS-MIC (2014) first development in RGB-HD technology
25µm
20µm
HD LowCT
Trenches filled with light absorbing material
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

24. The new trenches allow a reduction of about 25% at the same PDE
NUV-HD LowCT
40µm Cell Pitch, PDE at 400nm
Preliminary
– 25%
CrossTalk
NUV-HD
NUV-HD LowCT
The new trenches allow a reduction of about 25% at the same PDE
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

25. G. Zappala’ – Vienna Conference on Instrumentation 2016
Conclusions
High-Density technology was successfully applied to NUV-SiPMs investigating many cell pitches.
Most important results:
PDE > 60% at 400nm for 40µm
Average DCR < 100 kHz/mm2
Cross-Talk at 10% with PDE > 40% at 400nm
NUV-HD are suitable for many applications
Promising results from LowCT technology were shown, further studies are still on going
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

26. Performance of the latest prototypes of NUV-HD Silicon Photomultipliers
G. Zappalà, F. Acerbi, A. Ferri, A. Gola, G. Paternoster, C. Piemonte, V. Regazzoni, N. Zorzi

27. Backup Slides

28. FBK SiPM in VCI 2013
Two technologies were presented: RGB and NUV SiPMs NUV-SiPM designed to detect Near-UltraViolet light
SiPM NUV
Cell pitch 50µm with 42% Fill Factor
Primary Noise ~ 100 kHz/mm2
ECF (Excess Charge Factor) mainly determined
by Delayed Correlated Noise
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

29. G. Zappala’ – Vienna Conference on Instrumentation 2016
New substrate
To reduce the delayed correlated noise (DeCT & APdiff)  different kind of substrate, with reduced carrier lifetime
UV Photon
Secondary
Photons
(Old) Substrate
Diffusion length ~ 6µm
(New) Substrate
Diffusion length ~ 400nm
We fabricated devices with the same layout and epitaxial layer
(Old) Substrate
DeCT & AP
DiCT
(New) Substrate
(F. Acerbi et. al., IEEE T. Nucl. Sci., Vol. 62, n.3, 2015)
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

30. Performance with new substrate
(Old)
(New)
(Old) OV OV
Greater maximum operating bias voltage
Higher PDE
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

31. Performance with new substrate
The new Substrate has always a lower correlated noise probability
Breakpoint Old-New Substrate
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

32. G. Zappala’ – Vienna Conference on Instrumentation 2016
Excess Noise Factor
PDE > 45 %
25µm
30µm
35µm
40µm
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

33. NUV-HD in gamma-ray spectroscopy
𝒅𝑬 𝑬 𝟐 ∝ 𝟏 𝑷𝑫𝑬 𝑬𝑵𝑭 +…
LYSO
LaBr3
BGO
25µm
30µm
35µm
40µm
ENF measured on SiPM without scintillator
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016

34. Energy Resolution of CeBr3
SiPM NUV-HD 4x4mm2, cell pitch 25µm
CeBr3 4x4x11mm3 (crystal provided by J. Schmall and J. Karp)
~1%
Energy resolution in range 5.5% – 7.0%
Statistical error + crystal coupling ~ 1%
(F. G. A. Quarati et. al., Nucl. Instr. Meth. A 735 (2013))
16 Feb. 2016
G. Zappala’ – Vienna Conference on Instrumentation 2016