Review of Solidstate Photomultiplier. Developments by CPTA & Photonique SA

Transcription

1 Review of Solidstate Photomultiplier Developments by CPTA & Photonique SA Victor Golovin Center for Prospective Technologies & Apparatus (CPTA) & David McNally - Photonique SA 1

2 Overview CPTA & Photonique SSPMs: Implementation & Recent developments Some SSPM applications Outlook 2

3 2004: Photonique & CPTA Founded Photonique SA first commercial provider of pixelated Geiger mode Avalanche Photodiodes outside Russian Federation 2007: R&D and commercial joint-venture btw. CPTA and Photonique 1980 s: V. Golovin & Z. Sadygov propose first MRS-APD working at MELZ in Moscow: 1988 A.G. Gasanov, V.M. Golovin, Z.Y. Sadygov, N.Y. Yusipov "Avalanche photodiode based on MRS structure", Lett. J. Tech. Phys. 14 (1988) 806 (in Russian). 3

4 Historic wrap-up 1990: V. Golovin creates CPTA continues R&D on SSPM implementation 1998: V. Golovin files patent for trench separation of micro-cells: 4

5 n + p p + Structure for Visible Light Applications Trench Architecture High fill / geometric factor Low optical cross talk Low excess noise Uniform Electric field Drawing from (*): 10µm Photo from (*): (*) O. Mineev et al. Scintillator counters with multi-pixel avalanche photodiode readout for the ND280 detector of the T2K experiment; NIM A 577 (07) 5

6 Visible Light Sensor Line-Up CPTA 6

7 Performance Evolution CPTA Improved n+ p junction Optimized doping concentrations Optimized n+ layer thickness Improved trench geometry Better field uniformity PDE [%] Evolution of Spectral Sensitivity L(Y)SO Wavelength [nm] Y V V Reference (*): 2005: V b = ~100V; V ov = V bias V b up to 4V (i.e. 4% of V b ) 2007: V b = ~ 17V; V ov = V bias V b up to 8V (i.e. 45% of V b ) (*) 2005: SSPM_040901GV_TO18; 2007: SSPM_0701BG_TO18 7

8 Geometric or Fill Factor Step size in X/Y: 1µm Low intensity laser beam <<1 photon per DAQ cycle SSPM Beam spot at SSPM surface: 1σ 5µm TDC 10ns gate Select if exactly 1 micro-cell fired Picture from (*): Architecture exhibits sensitivity in all areas not occupied by trench 2006: Micro cell size: 43µm; Fill Factor ~60% 2008: Micro cell size: 33µm; Fill Factor >60% Trench width 4µm (*) Peter Križan, University of Ljublijana & J. Stefan Institute Presentation at LIGHT07 Ringberg Castle - Germany 8

9 Optical Cross-Talk Trench architecture significantly reduces optical cross talk and allows for improved tuning of readout threshold No Trench: Crosstalk: 20% 30% Optical excitation of neighbouring cells reduce effectiveness of applied readout threshold With Trench: Crosstalk: 1% 3% Small changes in readout threshold allow for wide range of S/N tuning Dark count rate [khz] Graph from (*): Threshold in photo-electrons equivalent (*) Y. Musienko Advances in multipixel Geiger-mode avalanche photodiodes (silicon photomultipliers); to be published in NIM A (08) 9

10 Quenching Resistor Affects: Cell Recovery Time & Afterpulsing Can tune micro-cell quenching resistor value betwee 0.7MΩ and 100MΩ Fast recovery ~70ns Modest afterpulsing: Slower recovery ~10µsec Low afterpulsing <10% in 100ns gate ~1-3% in 100ns gate Note: Micro-cell capacitance ~100fF 10

11 Temperature Stability of Signal Amplitude (I) Amplitude Signal = N Photons x PDE(T) x Gain(T) PDE(515 nm) [%] PDE at 515nm vs. Bias Voltage T= 22 C T=-28 C Bias Voltage (*) (*) Gain* Gain vs. Bias Voltage T= 22 C T=-28 C Bias Voltage T = - 28C o T = + 22C o Wide V op range results in reduced slope in the PDE vs. Bias Gain vs. Bias curves. and (*): SSPM_050701GR 11

12 Temperature Stability of Signal Amplitude (II) A wide V op range over V b reduces temperature dependence of signal amplitude Temperature dependence of Signal Amplituded as function of applied bias voltage Amplitude Temperature correlation is <1% for bulk of operating range. 1/A da/dt [%] Bias voltage [V] (*) (*) SSPM_0701BG 12

13 Sensitivity Enhancement for Blue/UV Light Wavelength shifter applied to sensor surface boosts blue sensitivity. Technique can be tuned to respective target spectral range PDE [%] Blue Sensitivity Enhancement Standard 40 Blue-enhanced L(Y)SO Wavelength [nm] (*) Work ongoing for: Deep UV spectral range / Selective spectral sensitivity Fast wavelength shifters (*) Standard: SSPM_0701BG Enhanced available on ASS_0604BE 4-element linear array 13

14 Stability Accelerated Aging Test Measurement from (*) Long-term stability test shows no performance degradation over time 30 days at 80C o 260 days at 18 ~ 27C o Uncertainty of data points: ±2 p.e. (*) O. Mineev et al. Scintillator counters with multi-pixel avalanche photodiode readout for the ND280 detector of the T2K experiment; NIM A 577 (07) 14

15 Reliability Based on sales between 2004 and 2008: Long-term failure rate of shipped sensors is less than 1 in Example: Device failed due to incorrect biasing: Vaporized bonding wire 15

16 UV-Blue Sensitive Architecture CPTA Reverse doping structure Favours electron propagation towards p + p junction First implemented in

17 Performance Evolution CPTA Over the last two years we have significantly improved implementation of this structure Still fighting against dark counts: 3 ~ 5 MHz / mm 2 Working on wavelength shifter enhanced devices for deep UV applications PDE [%] (*) Spectral Sensitivity of p+ p n+ Architecture : 1mm2 2007: 4.4mm Wavelength [nm] (*) 2005: SSPM_050901B 2007: SSPM_0611B1MM 17

18 Applications - PET (I) 1mm 2 visible light SSPM (1) 9mm 2 SSPM with W.L.S. (2) LYSO: 2 x 2 x 10 mm Source: 22 Na 511keV Measurements from (*): de/e (FWHM) 18 % 13.5 % Timing resolution (FWHM) 1.0 ns 1.3 ns (*) Y. Musienko et al. Study of multi-pixel Geiger-mode avalanche photodiodes as a read-out for PET; NIM A 571 (07) (1): SSPM_0701BG (2): SSPM_0604BE 18

19 Applications - PET (II) LYSO 3 x 3 x 10mm 2 x 2 element core matrix (3.3mm sensor pitch) of 4.4mm 2 visible light SSPMs no W.L.S. with W.L.S. de/e (FWHM) 19 % 15 % Timing resolution (FWHM) < 1.0 ns 2.5 ns Crystal: 4 x 4 x 20mm LYSO Source: Cs137 (662keV) Fibre: Kurray Y11 From (*) SSPM Coupling de/e (FWHM) 1x1mm fibre single 16.7% 1x1mm fibre-double 14.1% (*) Photo & Measurement taken from talk: Y. Musienko: EuroMedim Marseille 19

20 Applications: Radiation Detectors CPTA Scintillation Tiles with MRS-APD readout (START) (*) Cost effective & scalable technique Working on calorimetric solutions (*) All pictures & graphs from: K. Voloshin et al.: Scintillation counter with MRS APD light readout; NIM A 539 (2005) 20

21 Outlook Higher cell density maintaining peak PDE 40% Noise / Dark-count rate reduction: Target ~100kHz / mm 22C o Larger sensor area p+ p n+ (blue sensitive) PDE Target ~40% at L(Y)SO peak Sensitivity down to 150nm Reduce dark count rate Arrays: Both monolithic and packaged discrete dies Position sensitive SSPMs 21

22 Thank you for your attention Photonique SA ch du Grand-Puits Meyrin Switzerland Web: Phone: Fax: Skype: photonique_sa 22