Electron-Bombarded CMOS

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1 New Megapixel Single Photon Position Sensitive HPD: Electron-Bombarded CMOS University of Lyon / CNRS-IN2P3 in collaboration with J. Baudot, E. Chabanat, P. Depasse, W. Dulinski, N. Estre, M. Winter N56: Photon Detectors and Radiation Imaging Detectors IV Outline: EBCMOS : Principle of detection and key points EBMI5 first prototype characterisation results LUSIPHER : status of the second prototype Summary & Future plans 1

2 EBCMOS : Principle of detection and key parameters EBCMOS : Electron Bombarded CMOS is a Proximity focusing Hybrid Photo-Detector. Single photon sensitivity & localisation V(kV) DC SNR Visible photon resolution few mm carrier Photo-electron photocathode Back-thinned CMOS HV E 1 mm Gap (mm) 3 cm 2 Vacuum tube design : V accelerating potential, E field, L gap => Dark Count rate, PSF of the photoelectron, SNR V 0r ph.e. radial initial energy => PSF CMOS Design and Post-processing: thinning procedure : down to epilayer : 30 um epilayer thickness : 8 um dead layer thickness : Post-Processing : < 200 nm Noise 10 ENC : SNR on the seed pixel >15 Backside detection Back-thinning postprocessing 2

EBMI5 in a nutshell EBMI5 is our first EBCMOS prototype with a back-thinned MIMOSA5 chip Cathode and Tube : S20 Cathode: QE @ 620 nm = 8 % @ 555 nm : 12

2 mm High Voltage for single photon sensitivity: [5-8] kv Back-thinned CMOS : MIMOSA5 AMS 0.

3 EBMI5 in a nutshell EBMI5 is our first EBCMOS prototype with a back-thinned MIMOSA5 chip Cathode and Tube : S20 Cathode: 620 nm = nm : 12 % 475 nm : 17 % Useful Cathode Diameter = 18 mm S= 2.5 cm 2 Cathode-CMOS Gap: ~ 1.2 mm High Voltage for single photon sensitivity: [5-8] kv Back-thinned CMOS : MIMOSA5 AMS 0.6 micron; 3T in pixel circuitry; Back thinning and post process : dead layer [ ] nm 1Kx1K pixels; 17 micron pitch Serial readout architecture with Pixel Clock < 20 MHz Integration time : 13 ms Offline CDS Duty cycle = 50 % Dynamical range: 30 ph.e. / pixel 3T architecture 3

4 EBMI5 characterization : Sensitivity and Dark Count Sensitivity to single photoelectron 1 Ph.e. <SNR> ~ 15 on the 8 kv Single photo-electron event Dark Count Versus T Versus HV #DC Field effect dominates for T < 10 C #DC 1600 Field effect 10 Thermionic Effect & Field effect

current ~ 650 ph.e. / frame / 2.5cm 2 7.10-4 DC/pix/frame => 100 Hz/mm 2 EMCCD Ixon DU897 : 5.

5 EBMI5 characterization : Dark count Filtering can suppress most of the Dark count from the cathode Raw data After simple filter between to consecutive frame Fluorescent beads Conclusion: dark count HV = 6 kv, T = 10 C Dark current ~ 650 ph.e. / frame / 2.5cm DC/pix/frame => 100 Hz/mm 2 EMCCD Ixon DU897 : evt/pix/frame => 650 Hz/mm 2 Dark count from cathode can be suppressed with simple filtering : Cathode DC > 10 clusters/frame (27 ms) 5

6 EBCMOS : Resolution The spatial resolution of the EBCMOS is a convolution of 2 point spread functions : 1. PSF of the photoelectron due to initial radial energy at the cathode level 2. PSF of the CMOS due to charge diffusion of the electrons into the epilayer Cathode 1 ph.e. V 0r PSF 1 e - E=V/L PSF Tube : σ = 12 µm FWHM L V V 0r Pixels N e- Charge spread: σ = 8 µm COG Alg. : σ = 2 µm PSF PSF 2 Analog output single photon counting mode σ = 15 µm 6

EBMI5 Resolution study PSF measurement with single photo-electrons on optical

pixels Lilly cells tagged with GFP σ L V 0r V Eta function clustering is

7 EBMI5 Resolution study PSF measurement with single photo-electrons on optical test bench: Spot Calibration slope <n_ph> Green LED Red LED Spot : FWHM < 1 µm Spot RMS 1.24 Green LED RMS 1.17 Red LED ( µs ) pulse duration Example of deconvolution Zoom on 100x100 pixels Lilly cells tagged with GFP σ L V 0r V Eta function clustering is necessary to extract PSF w.r.t. λ Conclusion: PSF of the Tube : σ = 11.6 µm (@ 540 nm ) PSF of the Tube can be used for deconvolution 7

Poisson Distribution Clustering with association probability to one photoelectron into the same contour : Deterministic

8 EBMI5 Multi-photon spectrum and localization Single photon Position Finding with Deterministic Annealing Algorithm Multi-photon spectrum to single photon position! Integrated image of the spot 2 Qdots! Poisson Distribution Clustering with association probability to one photoelectron into the same contour : Deterministic Annealing Algorithm Cluster charge spectrum Conclusion: Photon counting capability with multi-hits localization of the photons into the same cluster Reconstructed photoelectron Distribution 8

rate 1 to 10 khz - Large scale chip 1Kx1K : 10 % occupancy rate - Resolution : small pitch 10 um (Analogue / Digital readout) - Sensitivity to one photoelectron

9 LUSIPHER : temporal tracking for ultra high resolution Microscopy? Large-scale Ultra-fast SIngle PHoto-electron recorder Beyond Integration mode : Photon counting Mode 35 fps -> 500 fps Caméra LUSIPHER Specifications : - frame rate 1 to 10 khz - Large scale chip 1Kx1K : 10 % occupancy rate - Resolution : small pitch 10 um (Analogue / Digital readout) - Sensitivity to one photoelectron - Multi-photoelectron cluster algorithm to recover single photoelectron counting and localisation Quantum Dots Size < 100 nm Excitation at 560 nm Emission at 605 nm Proof of the concept Offline Kalman filter Next step : Hardware (FPGA) Implementation of KF

25 micron technology 400x800 pixels; 8 // analogue outputs; 40 MHz clock Readout modes : CDS not implemented into the pixel -Rolling Shutter mode : 1 ms integration time but 50 % duty cycle -Readout

10 LUSIPHER prototype Vacuum Tube: S20 cathode HV < 1.8 kv GAP < 800 um -> better resolution : 10 um expected Chip design : 4mmx8mm sensitive surface Diode optimized for CCE and Noise Reduction 10 micron pitch micron technology 400x800 pixels; 8 // analogue outputs; 40 MHz clock Readout modes : CDS not implemented into the pixel -Rolling Shutter mode : 1 ms integration time but 50 % duty cycle -Readout Reset Readout / line readout mode : 100 % duty cycle but 2ms integration time Ethernet Acquisition Board Evaluation of DAQ with FPGAs : Nios 2 Altera Development Card Mezzanine Card with 4 ADC 12 bits MAC Ethernet embedded : UDP 1 Gbit/s Filtering validation Clustering and sparsification implemented CDS implemented (FR1-Fr0) Performances : 1 Gbits/s achieved with continuous readout 400 x 800 0,25 um chip

Chip characterisation with Fe55 source The Chip works! Noise : 8 e- @ 40 MHz clock Calibration peak : C = 5.

11 Chip characterisation with Fe55 source The Chip works! Noise : 8 40 MHz clock Calibration peak : C = 5.24 e-/adc Expected Dynamic : 6 2 kv CCE = 105/176 = 60 % Post processing should change the CCE 11

12 DAQ validation : Frame rate DAQ : Full frame CDS (400x400) MHz Continuous readout : Rate = 640 Mbits/s (CDS 8 bits) 500 images/s continuous full frame readout : display 12

13 Summary EBMI5, First Prototype : Concept has been proved EBCMOS Concept has been proved with a slow version 35 fps. Single photon sensitivity is obtained Resolution has been measured and deconvolution of the PSF has been tested Multi-Photon counting mode gives interesting results DC Temporal Filtering gives good results on images Evaluation on Microscope setups in Fluorescence Imaging with Quantum Dots and Fluorescent proteins has been performed (compare with EMCCD G=1000!) LUSIPHER, Second Prototype: 2009 A Medium scale chip has been design in a new technology : 1 khz frame rate DAQ system has been evaluated on Nios 2 development Card o with Gbits/s Ethernet o 3x3 Clustering and Filtering o CDS LUSIPHER EBCMOS should be delivered in March and tested o Thanks for your attention! 13

Performance study of a MegaPixel single photon position sensitive photodetector EBCMOS

Performance study of a MegaPixel single photon position sensitive photodetector EBCMOS Rémi Barbier,1 IPNL, rue E. Fermi 696 Villeurbanne Cedex, France J. Baudot b, E. Chabanat 1, P. Depasse 1, W. Dulinski