1 / 23

HgCdTe avalanche photodiodes development at CEA/Leti-Minatec

2009. HgCdTe avalanche photodiodes development at CEA/Leti-Minatec. Johan Rothman CEA: L. Mollard, S. Bisotto Sofradir: X. Lefoule, F. Pistone. Outline. HgCdTe e-APD development in France Why HgCdTe e-APDs? Performance Applications HgCdTe e-APDs for photon-counting

jabari
Download Presentation

HgCdTe avalanche photodiodes development at CEA/Leti-Minatec

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 2009 HgCdTe avalanche photodiodes development at CEA/Leti-Minatec Johan Rothman CEA: L. Mollard, S. Bisotto Sofradir: X. Lefoule, F. Pistone Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  2. Outline • HgCdTe e-APD development in France • Why HgCdTe e-APDs? • Performance • Applications • HgCdTe e-APDs for photon-counting • Focal plane array results • HgCdTe e-APD road map at LETI-Minatec and Sofradir • Conclusion/perspectives Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  3. HgCdTe e-APD development in France CEA/LETI E-APD technology and design Epitaxy, µ-tech. E-APD physics and test Response time Multiplication process (gain, noise) Sensitivity limits ROIC design EO FPA test Detector lab and fab Sofradir • ROIC design • EO FPA test • E-APD FPA industrialisation • Fab etc.. System labs e-APDs Astro-physics labs • LAOG ( Grenoble) and LAM (Marseille) • Adaptiv optics, fringe tracking • Photon-counting imaging ONERA • E-APD physics • Multiplication process (gain, noise) • EO FPA test Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  4. The photodiode: an ideal light detector? High timing resolution QE100% i.e. no loss of information High Sensitivity Dark currents can be lower than 1 electron/s Limited by proximity-electronics (PE) noise Can be reduced by amplified photo detection! M x Photo-current M PE noise Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  5. APDs Advantages vs. Photo-multipliers or amplified-CCD High Quantum efficiency  100% All detection-modes are possible Photon-counting Real time measurement of the flux f(t) at high speed Integration (standard imaging operation)  Non-linear geiger mode (avalanche breakdown) Small and fast Compatible with imaging and telecom applications …but furious (other than HgCdTe-APDs…) Multiplication of both electrons and holes in Si and III-V material APDs Gain is strongly dependent on junction profile High dispersion (not good for imaging) Strong degradation of the SNR: F=SNRSNL/SNRout>2-5 at M>10 Response time is slowed down at high gain  Limited gain- Band-Width product < 340GHz (Intel record, Nature Photonics, 3, 2008) After pulsing probability >0 (photon counting) Dead time (photon counting) Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  6. Exclusive electron multiplication in HgCdTe APDs HgCdTe e-APD lc=5µm, T=80K • Exponential gain without avalanche break down (Beck,DRS, 2001) • Exclusive electron multiplication  • Felectric~1-1.2 (DRS, SELEX, LETI, BAE, TELEDYNE) • Response time independent of gain GBW>16THz (LETI) • Low gain dispersion • Noise equivalent input counts Neq_in< 10 000 e/s (LETI, DRS) • Stable up to M>5000 (LETI APD Record, 2006) • PLUS all the standard properties of HgCdTe • High quantum efficiency (close to 100% internal QE) • Detect wavelengths from visible to IR (with QE~100%) • Low operating temperatures due to small Eg Gain M=I/ICC Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  7. A new horizon of applications from visible to IR wavelengths with MCT e-APDs :(M>1000, F~1, Neq_in<10 000 e/s) This talk (1) • Photon counting • Quantum optics • Physics, astronomy, quantum cryptography • Imaging in Astronomy, biomedical applications, high-energy physics • Astronomy : higher order correlation functions! • Real-time measurements • Telecommunications • Time resolved Raman and Fluorescence spectroscopy, Doppler effect • Environmental surveillance, element recognition • Real-time dynamics observations • Integration (Imaging FPAs) • Active laser assisted imaging • Long range identification, safe planetary landing (NASA), bio-medical (fluorescence imaging), observation through semi transparent surfaces • Passive amplified imaging • Low flux applications ; hyper spectral imaging, wave front detection for astronomy, high dynamic range • The geiger modes is not (yet) possible due to the absence of avalanche break-down threshold This talk (2) Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  8. Performance optimization of HgCdTe e-APDs? • MW (lc=4.2-5µm) e-APD performances: • M>100, F=1.2, Ieq_in~10000 e/s, tresp~2 ns, Top<100K Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  9. Photon counting Counter : Direct pixel digitalization • Read-out noise supression • High dynamic range (>16 bit) • High frame-rate • Dark-current thresholding Timer :Estimation of the time of arrival of the photons • 3D imaging • Quantum optics and imaging • higher order photon correlation functions Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  10. Exclusive electron multiplication for Linear mode proportional photon counting Low F Proportional photon counting Distinguish the number of photons that arrives simultaneously in the depletion layer (not possible in GM-APDs) Reduce after-pulsing effects 0% (GM –APDs ~10%) High order temporal correlation function A new window for astronomy ! No quenching  high repetition rates >GHz is possible (GM-APDs ~ 10MHz) Output count probability distribution for <M>=300 and F=1.04 1 photon 2 photons Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  11. Exclusive electron multiplication for Linear mode proportional photon counting Low F Proportional photon counting Reduce after-pulsing effects (GM –APDs ~10%) No quenching  high repition rate >GHz is possible (GM-APDs ~ 10MHz) Low F  Discrimination of non-amplified dark current Low DCR Depends on the distribution of the dark current generation Homogeneous distribution <M>dark=52 for Mdiff=300 Output count probability distribution for <M>=300 and F=1.04 DC generation Distributed dark-current generation p i n 1 photon 2 photons <M>dark Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  12. Response time optimization in APDs Collection of minority electrons Diffusion ~ 1-5 ns1 Drift (xCd gradient)  Vd of e in p type HgCdTe  50-100 ps jitter3 Transit time of e and h Vd(E) : th=10-50ps  GBW limit ~20THz (MW)1,2 RC charge evacuation ~ 10-50 ps Ultimate photon counting timing resolution <100ps! Response time jitter  limits the timing precision Collection of minority electrons p Transit time of eand h n- Depletion layer = mutliplication region E RC charge evacuation n+ • G. Perrais et al. JEM, 37, 2008 • G. Perrais et al. JEM, 38, 2009 • J. Rothman et al. to be published, JEM, 40 (2010) Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  13. CTIA coupled one-shot TOF+R imaging (3D) Pulse detection in C10(1) Sample time sweep  TOF (2) Switch to integrate the total light pulse in C20(3) First move towards photon counting (2008): Active 3D Imaging 4x10 test FPA, 40µm pitch First 3D event driven pixel (2) TOF noise measured with a flux of 560/e per pixel, at M=100 variable delay, T=80K (1) (3) Vsub<0V "Advanced pixel design for infrared 3D LADAR imaging" F. Guellec, SPIE DSS, 6940-84 • Sequential and spatial DTOF<2ns over 4x10 pixels  range resolution < 30 cm • 320x256, 30µm pitch array under test today • Objectives: DTOF<2 ns and read noise < 2 e- Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  14. Gain performance in e-APDs (xCd) lc=3.3 µm MBE lc=4.2 µm LPE • Exponential gain  exclusive electron multiplication at M>600 for lc=2.9 µm (T=80K) • Hole multiplication is still negliable up to high gains at high xcd • lc=2.9µm is compatible with high operating temperature active laser imaging (Isat~20pA in VHg doped MCT at T=200K) • Gain is dependent on junction geometry also at lc=2.9µm lc=5.3 µm LPE lc=2.9 µm MBE lc=2.9 µm MBE, larger depletion layer Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  15. Excess noise factor in lc=2.9µm e-APD (T=80 K) Noise factor F~1 for lc=2.9 µm MCT e-APD up to M=600 Noise is √F higher than the shot-noise Consistent with a high stability of the exclusive electron multiplication at high xCd Absence of 1/f noise ! M=600 M=60 M=10 M=1 Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  16. e-APD sensitivity :Equivalent input dark current M=100, T=80K: Ieq_in =200-500 fA at M=100 for lc=5.3 µm Strong reduction for shorter lc  Ieq_in~ fA (10 ke/s) Needs Low noise ROIC to measure at M<100 or lc<4µm M<300 Icc=0, A1, ZF Icc=0, A2, ZF Icc, A1, RF Icc, A2, RF Test array diode Measurements without ROIC M=380 ROIC needed Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  17. 320x256 30µm pitch MCT bi-mode e-APD FPASuccess of DEFIR in 2009 (collaboration with Sofradir) MW e-APD, lc=5.3µm à 80K TIA 2D identification : Cactive=30fF (0.3Me, 90 e rms noise) M Passive thermal surveillance Cpassive=120fF (1.2Me, 150 e rms noise) 3:rd demonstration of large format e-APD FPA for 2D imaging Selex (2004) , DRS (2006), both with gain operability of 99% Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  18. 320x256 30µm pitch MCT bi-mode e-APD FPA Gain measurements Test array / FPA gain f/2, 5V <M>=14.1 s/<M>=7.7% Op50%=99.84% • An identical gain is measured in test-arrays and FPAs • Record high 99.8% operability • QE>70% • FPA compatible low gain dispersion (<10%) up to 7V reverse bias • Gain dispersion is dominated by the EPL ripple • Reduced dispersion by using MBE or reduced ripple EPL • Excess noise factor Fmax=1.4 (consistent with similar test diodes) • Excess noise factor operability <F>+/-100%=99.7% up to M=70! Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  19. 320x256 MW HgCdTe e-APD lc=5.4 µm, T=80 K(Narrow multiplication layer  tunneling) <M>dark<< <M>cont_gen. for M>10: Dark current can be suppressed using photon counting thresholding 4.5V, M=25, C1=120fF, tint=300µs Ieq_in=70 fA (420 ke/s) Flux (BB at T=290K) Zero flux FOV=0° + Photon leakage Ieq_in 3.5V, M=10, C1=120fF, tint=40ms Ieq_in=10 fA (60 ke/s) Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  20. 320x256 30µm pitch lc=3.3µm T=80K Gain ~test array gain <Mdark>=2.6 ~ <M>cont_gen=2.7 continuos GR in the junction at low gain Flux (BB at T=290K) 6 V, M=6 (sM/M=2.3%), C1=30fF, tint=2 s Ieq_in=95 aA (590 e/s) Zero flux M=6 Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  21. e-APD sensitivity :Equivalent input dark current M=100, T=80K: Reduction is lower than M=100 trend line Evaluation of parameter space is under way xCd, gain, LPE, MBE hetero-structure APDs Icc=0, A1, ZF Icc=0, A2, ZF Icc, A1, RF Icc, A2, RF MMW-FPA=10 M=380 MSW-FPA=6 (590 e-/s) Late news data (14/10/2009): M=24 (12 e-/s) at 10.5V Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  22. LETI/Sofradir HgCdTe e-APD Road-map photon counting Single element Q4 Real time BW>GHz Single element Wavefront/Fringe tracking 320x256, > 1.5kFPS, noise < 2 e- 2010 2009 2011 Exclusive electron multiplication HgCdTe APDs • Optimizing HgCdTe e-APDs • Operability >99.9%, low dark noise (10 e-/s), speed (<100ps) • Develop dedicated proximity electronics to address a maximum of applications (RON < 1 e-) Q2 2D Active/passive FPA 320x256, p30µm Q3 3D Active FPA 320x256, p30µm Photon counting array Format to be defined Q3 2D DTOF imaging 320x256, p30µm Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

  23. Conclusions/Perspectives • MCT e-APDs • F~1 at M>600 for lc=2.9 µm to 5.4 µm at T=80K • Linear mode photon counting • Proportional counting (detect 1, 2.. photons) • Discriminate non-amplified dark currents • Low DCR • Timing precision  below 100 ps • No after pulsing is expected • ROIC (CMOS)-design is the key to harnest the potential of MCT e-APDs • 2D active imaging array • Neq_in<12 e-/s in lc=2.9 µm array at M=25  enables wave front sensing • 3D AI array under testing : timing precision~1ns (15cm) • 2010 • Low noise-high speed wave front sensor • Neq_in < 1 e-/s at M>10 • Single element photon counting Detectors for Astronomy Workshop 2009 - HgCdTe e-APDs at CEA/LETI - Johan Rothman

More Related