Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.eso.org/~gfinger/toulouse_2011/WELLER%20SELEX%20GALILEO_CNES_workshop_67Dec_IS2_HW_finalx.pdf Äàòà èçìåíåíèÿ: Fri Dec 16 13:17:26 2011 Äàòà èíäåêñèðîâàíèÿ: Tue Oct 2 10:01:06 2012 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: ëåãèðîâàíèå

CMOS Image Sensors for High Performance Applications Toulouse, France, 6th & 7th December 2011

IR Detectors Developments for Space Applications

Harald Weller SELEX GALILEO Infrared Ltd, Southampton, UK


SELEX GALILEO Southampton

· Nearly 50 years experience in research and development · Vertically integrated, Southampton's manufacturing starts from basic elements Hg, Cd and Te · Experienced in growing and processing a range of semiconductor materials (PC and PV technologies) · Clean room capacity and infrastructure to run higher volumes (11,200 m² facility of which 3,200 m² are cle an rooms) · Design of custom integrated read out circuits · Site highly specialised in packaging and testing of sensors (including cryogenics) with capability of moving into adjacent sensor markets · Developing electronics design capability


RECENT PROJECTS ­ SPACE APPLICATIONS

· MTG pre-development (2006-2010, concluded) · ESA-APD (2008-2011, concluded) · Sentinel 3 pre-development (2006-2007, concluded) · METimage pre-development (on-going) · ESO Gravity (on-going) · ESA Large Format Near InfraRed (LFNIR)


Evolution of APDs at SELEX-GALILEO

2001 2002
320x256, 2D, (SWIFT)

2003 2004 2005
320x256, 2D and Thermal Mode, (SWAN)

320x256, 2D and 3D, (SWALLOW)

2006 2007 2008 2009 2010
320x256, SW, High Speed, (SAPHIRA)

MAJOR TRIALS International Airborne

2011
320x256, Multifunctional, Thermal, 2D, 3D and Range Finder


SW APD - Application areas

1000

Photon counting or linear mode detectors

Cut-off wavelength

Avalanche gain

100

Burst Illumination LIDAR (BIL) imaging

2.5 µm 3 µm 3.5 µm 4 µm 4.5 µm
Low background flux applications

10

1 0 2 4 6 8 10 12 14 Bias volts


HgCdTe Avalanche Photodiode Detector with >2 um Cut-off Wavelength
ESA/ESTEC Contract 21751/08/N/EM


ESA APD ­ Objectives

Objectives of Contract ·Design and manufacture a mercury cadmium telluride (MCT) avalanche photodiode (APD) detector and Transimpedance (TIA) pre-amplifier circuit such that the MCT APD/TIA combination meets a set of performance criteria suitable for a LIDAR receiver ·Test and characterise the MCT-APD/TIA Why use MCT for Avalanche Photodiodes? ·Near-ideal single-carrier cascade avalanche ­ "almost noiseless" gain in the pixel ·Composition-tuneable bandgap ­ suitable for many IR wavelengths


ESA APD - Construction: Encapsulated Detector

Hybrid

Preamp Die

Final Device

Metallised Leadout

Encapsulation


ESA APD - Performance Criteria

Summary of Performance Demands
Parameter Operating wavelength Detector quantum efficiency Active area diameter Excess noise factor (F) Operating temperature Input signal/dynamic range. Bandwidth NEP Gain stability Linearity Total ionizing dose Proton irradiation Value 2051 nm > 70% > 150µm <1.5 > 200 K minimum: 8000 maximum: 2E6 >20 MHz < 100 fW/Hz 0.1% rms. 5% rms 5 krad (Si) minimum 1E10 p/cm2


ESA APD - Performance Summary

Summary Conditions: Low flux: Avalanche Bias: Signal Frequency: Noise frequency:

7.9kphotons/50ns/pixel from 1000K Blackbody Source 9.25 ± 0.05 Volts reverse bias 500Hz (mechanical chopper) 500kHz (10kHz measurement bandwidth)

Device Identity

Low Flux Signal mV

Low Flux Noise nV/Hz 73 164 112 114 245 161 96 130

White Noise (No flux) nV/Hz 54 70 54 65 150 82 52 62

Low Flux QE* 1.02 0.93 0.89 0.87 0.94 0.83 0.92 0.89

NEP fW/Hz 63 87 58 74 120 83 65 69

4720-E05 4721-G08 44092-L01 44092-M01 44092-I02 44092-J02 44092-K01 44092-K03

6.84 6.02 7.11 6.63 9.65 7.90 6.20 7.20


HgCdTe Avalanche Photodiode Detector with >2 um Cut-off Wavelength Radiation Testing


ESA APD - Dark Current: Whole Pixel

Dark Current
Det ect or 10G44092-K03 100

Element Dark Current at 9.3V bias (nA) 4720-E05

Before Radiation

After Radiation

El em ent Dark Current (nA)

38 160 170 880 500

47 160 170 860 430

10

Det ec tor*

4721-G08 44092-L01 44092-I02
1 5 5.5 6 6.5 7 7. 5 8 8. 5 9 9. 5 Diode Bi a s (V)

44092-J02


ESA APD - Total Ionising Dose

Facility: Dose rate: Condition: Time between irradiation and test:
44092-L01 Before Signal Noise (Low Flux) Noise (Blind) Gain Cut-off NE P 7 .1 1 112 54 6 .6 4 2.583 58 5kRad (Si) After 6 .2 2 111 52 5 .8 5 2.574 63 Change 12% 1% 4% 12% 0 .3 %

ESTEC Co-60, Noordwijk, Netherlands 2.5 krads/hr (approx) Powered, biased, room temperature 15 days
4720-E05 Units mV nV/Hz nV/Hz µm fW/Hz Signal Noise (Low Flux) Noise (Blind) Gain Cut-off NE P Before 6 .8 4 73 54 5 .5 6 2.618 63 10kRad (Si) After 6 .2 4 75 40 5 .2 9 2.614 50 Change 9% 3% 26% 5% 0 .2 % Units mV nV/Hz nV/Hz µm fW/Hz

-

-


ESA APD - Proton

Facility: Dose rate: Condition: Time between irradiation and test:
Device ID: 44092-I02 Dose: 1 â 1010 p+/cm², 10MeV eq. Before Signal Noise (Low Flux) Noise (Blind) Gain Cut-off NEP 9.65 245 150 8.49 2.57 124 After 12.8 219 94 11.3 2.595 57 Change 32.9% 10.6% 37.5% 33.3% 1.0% -

PSI, Villigen, Switzerland 1 â 10¹º protons/cm², 3â 10¹º protons/cm² (10MeV eq.). Unpowered, room temperature 57 days
Device ID: 44092-J02 Dose: 3 â 1010 p+/cm², 10MeV eq. Units mV Signal Noise (Low Flux) Noise (Blind) Gain Cut-off NEP Before 7.9 161 82 7.9 2.611 83 After 11.2 115 54 11.0 2.612 38 Change 42.1% 28.7% 33.8% 39.0% 0.0% Units mV nV/Hz nV/Hz µm fW/Hz

nV/Hz nV/Hz µm fW/Hz


ESA APD - Summary

·"Novel" approach of hybridising diode directly to TIA preamplifier has been successful ·Device is sensitive to primary wavelength (2.051µm) but also suited to other wavelengths (1.3µm to 2.2µm) ·The device exceeds the key performance criterion (NEP<100fW Hz) ·Most other performance criteria achieved (though some not fully demonstrated) ·Manufacturing method for diode established. Viability of manufacturing demonstrated ­ yields sustainable ·Encapsulated detector designed (and available for breadboard activities) ·Exploitation of device in LIDAR system yet to be demonstrated


SW APD MCT APD for Wavefront Sensors and Interferometry


Uniformity of avalanche gain

Normalised laser signal as function of avalanche gain
60 58 56 Output si gnal (m V) 54 52 50 48 46 44 42 40 350 360 370 380 390 400 Gain - x 14 Gain - x 28 Gain - x 38

Pix e l num be r

Avalanche gain adds virtually nothing to non-uniformity Depends only on voltage and alloy composition


Wavefront sensors and interferometry

Typical requirements: · · · · · · · · · · · Avalanche gains x10 to x30 Waveband in region of 1.0 to 2.5µm - mainly J,H and K band 256x256 ar r a y Frame rate >1KHz Sensitivity <3e rms at pixel rate of 5MHz/channel 24µm pixel size Multiple readout windows with independent reset Low noise floor Non-destructive readout 32 parallel outputs Temperature range 30K to 80K

Acknowledgements: All the data presented here is courtesy of European Southern Observatories, ESO With special thanks to Dr Gert Finger


SW APD evaluation at ESO

APD sensor
SELEX-Galileo Swallow 3D detector Operated in simple non-destructive read mode Voltage controlled avalanche gain 2.5µm cutoff arrays

ESO APD test kit
Cooled optics for few photons imaging Cryogenic symmetric pre-amplifier Two stage engine to 30K

Typical exposure


Avalanche gain versus bias voltage

black diamonds: measured exponential dependence on bias voltage

ROIC ME788 Cutoff wavelength - 2.45 µm Temperature - 40K

model

Data courtesy of ESO


Noise histogram with eAPD

APD sensor ROIC ME788 Cutoff - 2.45 µm Temperature - 40K Int. time ­ 5.06ms Bandwidth ­ 5MHz APD gain ­ 33x

Data courtesy of ESO


9.3 e/pixel test pattern versus APD gain

APD sensor ROIC ME788 Cutoff wavelength - 2.45 µm Temperature - 40K Integration time ­ 5.06ms Bandwidth ­ 5MHz Optics Filter K short Pattern contrast ­ 9.3 e/pixel

Data courtesy of ESO


1.75 e/pixel sensitivity with APD gain of 33

APD sensor ROIC ME788 Cutoff wavelength - 2.45 µm Temperature - 40K Integration time ­ 5.06ms Bandwidth ­ 5MHz APD gain ­ 33x Optics Filter K short Pattern contrast ­ 1.75 e/pixel Signal processing Double correlated clamp 16 frames averaged

Data courtesy of ESO


SW APD Fowler sampling

· number of nondestructive readouts increasing with integration time · 5.06 ms /frame · 2.7 erms 1 Fowler pair (DCS) · noise · integration time 42 ms 1.2 erms 8 Fowler pairs · for integration time 50ms shotnoise = with Idark=84 e/s · for c=2.65 µm HgCdTe 50 ms integration time possible without limiting sensitivity by shot noise

Data courtesy of ESO


SW APD Excess Noise Factor

· excess noise close to unity for APD gain up to 33 · excess noise determined form ratio of photometric gain and gain obtained from photon transfer curve

Data courtesy of ESO


Noise Histogram of SW APD

· ADP gain 33 · 5 MHz/channel

Data courtesy of ESO


Conclusions from pre-development study

Sensitivity <3e rms is achievable using HgCdTe eAPDs for imaging in J H and K band with 5MHz clock and >1KHz frame rate

SELEX-Galileo were down-selected to supply sensors for the GRAVITY Program and contracted to design a custom ROIC


APD sensors in the VLT Interferometer

European Southern Observatories, ESO Very Large Telescope, VLT ­ cluster of four 8.2m unit telescopes
The SW infrared APD detectors Critical to the GRAVITY system are the four infrared wavefront sensors and one fringe tracker to correct the atmospheric turbulence at each telescope, and stabilise the fringe phase in the VLTI beam relays. VLTI requirements · Adaptive optics needed to correct for atmospheric distortion using embedded sources (galactic center). · The IRIS instrument is used for simultaneous first order wavefront corrections (tip-tilt) of all 4 telescopes on a single detector APD wavefront sensor:
96x96

· · · · · ·

256x256 array at K band Frame rate >1KHz Sensitivity <3e rms at 5MHz 32 parallel outputs 24µm pixel size Non-destructive readout


SAPHIRA - full custom ROIC for GRAVITY

GRAVITY Full Custom ROIC - SAPHIRA
General architecture 320x256 on 24µm pitch with either 32, 16, 8 or 4 outputs Pixel mapping 32 outputs organised as 32 sequential pixels in row (ie row scan requires 10 clocks). Windowing Multiple windows each independently resettable Readout Non-destructive readout with internal glow protection permitting Fowler sampling with a large number of readouts to reduce readout noise to <1 e rms Full custom pixel SAPHIRA Designed for low intrinsic noise Variable integration capacitor 32 31 Voltage clamp to minimise persistence Glow protection 30 29 APD protection circuit 15fF integration node capacitance 28
27 26 25

16 15 14 13 12 11 10 9

24 23

8 7

22 21

6 5

20 19

18 17

1

2

34


Summary of eAPD arrays

SWIFT - Multifunctional Array · 2D and 3D Burst Illumination LIDAR · Thermal and low light level imaging · Scene-based laser range finding

SAPHIRA · Low Photon Flux Imaging · Spectroscopy · Ultra fast framing


Conclusions

· Benefits of SW APD for LIDAR receiver applications were demonstrated · APD radiation results obtained · Existing SW APD technology independently characterised, demonstrating sensitivity of <3e rms · Gravity custom ROIC for SW APD in development