MIT Lincoln Laboratory Verghese_AFRL101906-1 S. Verghese 10/19/06 Avalanche Photodiodes for 3-D...
-
date post
20-Dec-2015 -
Category
Documents
-
view
215 -
download
0
Transcript of MIT Lincoln Laboratory Verghese_AFRL101906-1 S. Verghese 10/19/06 Avalanche Photodiodes for 3-D...
MIT Lincoln Laboratory
Verghese_AFRL101906-1S. Verghese 10/19/06
Avalanche Photodiodes for 3-D LADAR and Communications*
S. Verghese
*This work was sponsored by the National Aeronautics and Space Administration (NASA) Goddard under the Department of the Air Force contract number FA8721-05-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the United States Government.
MIT Lincoln LaboratoryVerghese_AFRL101906-2S. Verghese 10/19/06
Key Technical Contributors
• InP APDs
• CMOS ROIC
K. A. McIntosh J. P. Donnelly E. K. Duerr D. C. Oakley
G. M. Smith L. J. Mahoney P. I. Hopman C. Vineis
K. E. Jensen K. M. Molvar J. Aversa S. H. Groves
J. M. Mahan Z.-L. Liau C. D. Parker A. Napoleone
F. J. O’Donnell M. P. Kesler E. A. Dauler K. Carbonari
T. J. McIver P. Chapnik J. E. Funk S. A. Hamilton
L. Retherford G. Lambert D. Chapman D. C. Shaver
E. J. Ouellette D. M. Cohen J. P. Frechette C. N. Stevenson
J. B. Glettler B. F. Aull M. Renzi S. Verghese
MIT Lincoln LaboratoryVerghese_AFRL101906-3S. Verghese 10/19/06
Geiger-Mode: Photon-to-Digital Conversion
• Single-photon sensitivity
• Low dark-count rate
• All-digital readout circuit
• Compact and low power
• Sub-ns timing
APD
Digitaltimingcircuit
Digitally encoded photon time-stamp
photon
Pixel circuit
Polyimidepassivation
4 mLensletArray
InP APDArray
CMOSROIC
InP
Su
bs
tra
te
InG
aA
sP a
bso
rber
InP
mu
ltip
lie
r
InP APD
Device Profile
Photons
MIT Lincoln LaboratoryVerghese_AFRL101906-4S. Verghese 10/19/06
InP Avalanche Photodiodes
• Introduction
• Applications
• APD Figures of Merit
• Read-Out Integrated Circuit (ROIC)
• Summary
MIT Lincoln LaboratoryVerghese_AFRL101906-5S. Verghese 10/19/06
JIGSAW: Short-range 3-D LADAR imaging*
OrganicAir Vehicle
• Locate and identify obscured targets within given area of 20 x 20 m
• Use angular diversity to maximize penetration of foliage
• Register and visualize data
• ID target from single pass
(100-m altitude)
Phase 1 OAV Ladar System
Mass: 0.34 kgVolume: 3 litersPower: 5 W
*Slide courtesy Dr. Rich Marino
MIT Lincoln LaboratoryVerghese_AFRL101906-6S. Verghese 10/19/06
RF Deep-Space Links are Power Limited
Neptu
ne
Uranu
s
Saturn
Jupi
ter
PlutoGEO Moon
dB GEO Link (R2)
0 10 20 30 40 50 60 70 80 90 100 110
36
000
km
VenusMercury
Mars
40
0 m
illi
on
km
34-m Receive Antenna, NASA Deep-Space Network
3-m Transmit Antenna,Mars Reconnaissance Orbiter
Mars Reconnaissance Orbiter
• Launched 8/05
• Ka-band, 32 GHz
• 35-W transmit power
• Data rates up to 2.8 Mbit/s
MIT Lincoln LaboratoryVerghese_AFRL101906-7S. Verghese 10/19/06
Neptu
ne
Uranu
s
Saturn
Jupi
ter
PlutoGEO Moon
36
000
km
VenusMercury
Mars
40
0 m
illi
on
km
5-m Receive Aperture,Hale Telescope
0.3-m Transmit Aperture,Mars Telecommunications Orbiter
Mars Laser CommunicationsDemonstration
• 1.06 m, optical carrier
• 5-W transmit power
• Data rates up to 46 Mbit/s
0 10 20 30 40 50 60 70 80 90 100 110
dB GEO Link (R2)
Optical Deep-Space Links are Photon Starved
MIT Lincoln LaboratoryVerghese_AFRL101906-8S. Verghese 10/19/06
InP Avalanche Photodiodes
• Introduction
• Applications
• APD Figures of Merit
– Photon Detection Efficiency (PDE)
– Reset Time
– Dark Count Rate (DCR)
• Read-Out Integrated Circuit (ROIC)
• Summary
MIT Lincoln LaboratoryVerghese_AFRL101906-9S. Verghese 10/19/06
PDE and Reset Time: 1.06 m APDs
Hermetic Package
Figures of Merit:
• Probability of Detection (45%)• Reset Time (1.6 s)• Dark Count Rate (20 kHz)
Polyimidepassivation
4 mLensletArray
InP APDArray
CMOSROIC
InP
Su
bs
tra
te
InG
aA
sP a
bso
rber
InP
mu
ltip
lie
r
InP APD
Device Profile
Photons
MIT Lincoln LaboratoryVerghese_AFRL101906-10S. Verghese 10/19/06
101 102 103 104 105-3
-2
-1
0
1x1 APD array 2x2 APD array 4x4 APD array 8x8 APD array
Blo
ckin
g L
oss
[d
B]
R (photon rate) [KHz]
APD Blocking Losses
Reset time: 1sDark count rate: 10KHz
Mitigating Reset-Time Blinding
2x2 Array
Photon rate per APD reduced by 4
1 2
3 4
10% signal loss fromsignal-flux blockage
• III-V Geiger-mode APDs must rest after firing for a hold-off time (tho), also called the Reset Time.
• Spreading the signal over many pixels reduces the odds of a signal photon striking a blinded pixel
• Eliminating the trapped carriers requires dramatic materials improvements
10 MHz
V bias Breakdown voltage
Rea
do
ut
tho
APD fire
thotho thotho
Breakdown voltage
Trapped Carriers
APD fire
V bias
Trapped Carriers
tho
V bias
APD fire
Trapped Carriers
Breakdown voltage
V bias Breakdown voltage
Rea
do
ut
tho
APD fire
thotho thotho
Breakdown voltage
Trapped Carriers
APD fire
V bias
Trapped Carriers
tho
V bias
APD fire
Trapped Carriers
Breakdown voltage
Blinded
Observing
APD pixel #2 (time-history)
TrappedCarriers
MIT Lincoln LaboratoryVerghese_AFRL101906-11S. Verghese 10/19/06
Hermetic Package
Figures of Merit:
• Probability of Detection (45%)• Reset Time (1.6 s)• Dark Count Rate (20 kHz)
Polyimidepassivation
4 mLensletArray
InP APDArray
CMOSROIC
InP
Su
bs
tra
te
InG
aA
sP a
bso
rber
InP
mu
ltip
lie
r
InP APD
Device Profile
Photons
Dark Count Rate: 1.06 m APDs
MIT Lincoln LaboratoryVerghese_AFRL101906-12S. Verghese 10/19/06
30 25 20 15 10 5 00
50
100
150
200
250
300
350
400
0.0
0.2
0.4
0.6
0.8
1.0
Ph
oto
n D
ete
cti
on
Eff
icie
nc
y
D
ark
Co
un
t R
ate
[k
Hz]
APD Photo Sensitive Diameter m]
Dark Count Rate
Photon Detection Efficiency
APD Diameter Optimization
Goal: Use APD diameter for minimum DCR and max PDE
PDE rolloff due to microlens coupling inefficiency
Desired Size
MIT Lincoln LaboratoryVerghese_AFRL101906-13S. Verghese 10/19/06
10um
10um
8um
8um
13um
CCS136 CCS192 CCS214 CCS268 CCS2681
10
100
1000
4.0V overbias 5.0V overbias
DC
R (
kHz)
Measured Results (1.06-um APDs)
Requirements (@PDR) DCR PDE Reset
Best Device (ccs136)(10C,10um diameter)
65 kHz 47% 1.6 us
DCR < 30kHz at T = 300K (13um diameter APD)
Dark-Count Rate (DCR)
Room Temperature
Effective device diameter
4 50
10
20
30
0.40
0.45
0.50
0.55
0.60
PD
E
Dark Count Rate
DC
R [
kH
z]
Overbias [V]
Photon Detection Efficiency
Photon Detection Efficiency (PDE)
Overbias (V)
PDE with latest devices 50%
MOCVD-growth run
-10 -5 0 5 100.0
0.2
0.4
0.6
0.8
1.0
Position [m]
Photo-response Profile
Then:
Now:
MIT Lincoln LaboratoryVerghese_AFRL101906-14S. Verghese 10/19/06
APD Performance (1.06 & 1.55 um)Expected
Near-term GOAL
Near-term GOAL
Jan. 2006 Performance
DCR X Reset = 0.12
Zero-bkgnd Blockage: -0.5
Microlens loss: -1.5 dB
DCR X Reset = 0.03
Zero-bkgnd Blockage: -0.14
Microlens loss: -1.5 dB
Yb Fiber Amplifier compatible ( = 1.06 m)
Parameter Current Device Performance
Comments
PDE (5V overbias) 45% 20 um diam APDs (15 um-photoactive)
DCR (5V, +25oC) 20 kHz 20 um diam APDs
Reset Time (+10oC) 1.6 us On CMOS ROIC
Parameter Current Device Performance
Comments
PDE (5V overbias) 40% 20 um diam APDs (15 um-photoactive)
DCR (5V, -33oC) 20 kHz 20 um diam APDs
Reset Time (-33oC) 6.0 us On CMOS ROIC
InGaAsP/InP Epitaxy InGaAs/InP Epitaxy
Jan. 2006 Performance
Er Fiber Amplifier compatible ( = 1.55 m)
Higher PDE and reduced lossHigher PDE and reduced loss
0.016
-0.07dB
-1.0 dB
0.06
-0.25 dB
-1.0 dB
10 kHz
55%
10 kHz
50%
MIT Lincoln LaboratoryVerghese_AFRL101906-15S. Verghese 10/19/06
LDES Receiver Test Bed
Avalanche Photodiodes:Single-photon arrival timing
Receiver Sync Board:Clock synchronizationFrame synchronizationAPD ROIC emulation
Receiver Workstation:PPM DemodulationTurbo DecodingDisplay and Diagnostics
MIT Lincoln LaboratoryVerghese_AFRL101906-16S. Verghese 10/19/06
Current development in LADAR APDs
• Increased Array Size
• Reduced Pixel Size
• Enhanced Processing, Functionality
• Spectral Coverage
Metric Requirement• Uniformity
256x64, 50 m
• 3D Integration
• Fast Reset, Counting, Low Jitter, Caching
• Other Materials
InP
5V SOI
2V SOICarrier wafer
MIT Lincoln LaboratoryVerghese_AFRL101906-17S. Verghese 10/19/06
InP Avalanche Photodiodes
• Introduction
• Applications
• APD Figures of Merit
– Photon Detection Efficiency (PDE)
– Reset Time
– Dark Count Rate (DCR)
• Read-Out Integrated Circuit (ROIC)
• Summary
MIT Lincoln LaboratoryVerghese_AFRL101906-18S. Verghese 10/19/06
3D Ladar Imaging at 1.06 m
• 1.064m Nd:YAG chip laser
• InGaAsP/InP APDs on CMOS
Detection probabilitycolor code
Rotatable 3D Image Conventional LADAR Array Concept:
• All pixels armed synchronously
• Low duty cycle (PRF dependent)
Observing (< 1us)
(Range Gate)
32
x3
2 G
M-A
PD
Arr
ay
1
2
3
4
Arr
ay R
ead
ou
t
Arr
ay R
ead
ou
t
Blinded (> 50us)
MIT Lincoln LaboratoryVerghese_AFRL101906-19S. Verghese 10/19/06
8x
8 G
M-A
PD
Arr
ay
1
2
3
4
Laser Communications at 1.06 m
• 1.06 m Yb-doped fiber amplifier
• InGaAsP/InP APDs on CMOS
Mars LaserCom
• All pixels armed asynchronously
• 100% duty cycle
Observing
MTO/MLT(cancelled)
LDES
OpticalDownlink
LaserCom Array Concept:
MIT Lincoln LaboratoryVerghese_AFRL101906-20S. Verghese 10/19/06
1 2 3 4 5 6 7 8
16 la
nes
@ 5
12 M
b/s
Frame-Store
Clock Gen
8x8 Array
TS_CLK1024 MHz
128-512 MHz CLKDiags
8 la
nes
@ 1
28-5
12 M
b/s
Mars LaserCom ROIC Block Diagram
• Single-clock input (TS_CLK)• Modest area and power consumption• User friendly (FPGA compatible, self-test, etc)
• Arm and disarm APD• Record time of photon arrival• Record location of photon arrival
ROIC Requirements: Design Guidelines:
APD
Digitaltimingcircuit
Encodedphotonarrival time
Lensletarray
ROIC Pixel Circuit
APDarray
CMOSROIC
Photons
~ 2 Vpp
MIT Lincoln LaboratoryVerghese_AFRL101906-21S. Verghese 10/19/06
1 2 3 4 5 6 7 8
16 la
nes
@ 5
12 M
b/s
Frame-Store
Clock Gen
8x8 Array
TS_CLK1024 MHz
128-512 MHz CLKDiags
8 la
nes
@ 1
28-5
12 M
b/s
Mars LaserCom Read-Out IC
• Mates to 8x8 InP APD array
• Rev2 chip: operating in test-bed
Pixel Cell Layout
Definition of Chip Architecture
Wafer-Probe Test Structures
MLCD ROIC Mirrored Copy
0.35-um CMOS Fab
Tested on Logic Analyzer at 311 MHz
Packaging and Test Verification (Jan ‘05) Simulations and Layout
DATA_I DATA_O
RE
SE
T
RRQBUS_I RRQBUS_O1
Pixel 7
TS_CLK
RESET8 MHz (derived on-chip from TS_CLK)
622 MHz (off-chip)
63
00000010
Data Off Chip
DATA_I DATA_O
RE
SE
T
RRQBUS_I RRQBUS_O0
Pixel 6
FIRED
(Time-slot 6
3)
DATA_I DATA_O
RE
SE
T
RRQBUS_I RRQBUS_O0
Pixel 8
TS
_C
LK
TS
_C
LK
TS
_C
LK
7 bits wide
DATA_I DATA_O
RE
SE
T
RRQBUS_I RRQBUS_O1
Pixel 7
TS_CLK
RESET8 MHz (derived on-chip from TS_CLK)
622 MHz (off-chip)
63
00000010
Data Off Chip
DATA_I DATA_O
RE
SE
T
RRQBUS_I RRQBUS_O0
Pixel 6
FIRED
(Time-slot 6
3)
DATA_I DATA_O
RE
SE
T
RRQBUS_I RRQBUS_O0
Pixel 8
TS
_C
LK
TS
_C
LK
TS
_C
LK
7 bits wide
Concept for Asynchronous APD Pixels (Jan ‘04)
BYPASSED
BYPASSED
MIT Lincoln LaboratoryVerghese_AFRL101906-22S. Verghese 10/19/06
Packaged LaserCom ROIC
Alumina InterposerAlumina Interposer
CMOS ROICCMOS ROIC
Package (lid removed)Package (lid removed)
0402 Cap0402 Cap
LVCMOS — LVDSTranslator Chip LVCMOS — LVDSTranslator Chip
0.5 in
2 in
MIT Lincoln LaboratoryVerghese_AFRL101906-23S. Verghese 10/19/06
Micro Lens Array Alignment
• APD active area (small ~10 um diam.)
• Demonstrated < 2um alignment error
• Submicron alignment in development
150 um 150 um
100 um
pitch
GaP InP
n1 n2
150 um 150 um
100 um
pitch
GaP InP
n1 n2
GaP Lens
Ray-trace
PhotoAbsorber
InP APDAPDarray
CMOSROIC
Lenslet array: 8x8 100-m pitch
CMOS ROICCMOS ROIC
Alumina InterposerAlumina Interposer
APD with u-lensAPD with u-lens
Active Alignment Diodes
Active Alignment Diodes I
xyz-stage APD
u-lens
1.064 um collimated source
I
xyz-stage APD
u-lens
1.064 um collimated source
Active Alignment for Low Loss
Microlens-Alignment Challenge:
MIT Lincoln LaboratoryVerghese_AFRL101906-24S. Verghese 10/19/06
Package for Mars LaserCom ROIC
• MIT/LL design; Kyocera fab
• Hermetic with integrated TEC
• 70 high-speed pins (< 6 GHz simulated)
APD Module
CuW Heat sink
Bezel
Alumina
APD/ROIC
KovarHousing
80% Ar20% He
Sapphire Window
TEC
MLA
Heat sink attached to cold plate through cold strap
APD Module
CuW Heat sink
Bezel
Alumina
APD/ROIC
KovarHousing
80% Ar20% He
Sapphire Window
TEC
MLA
APD Module
CuW Heat sink
Bezel
Alumina
APD/ROIC
KovarHousing
80% Ar20% He
Sapphire Window
TEC
MLA
Heat sink attached to cold plate through cold strap
Kovar housing
Ceramic package
CuWheatsink
Kyocera (160 PGA) MLCD Package w/ Rev2 ROIC & APD
160-pin Pin-Grid-Array Package
MIT Lincoln LaboratoryVerghese_AFRL101906-25S. Verghese 10/19/06
Current Development in APD Read-Out ICs
10 kHz 100 kHz 1000 kHz
Pixel refresh rate or PRF (Hz)
Arr
ay s
ize
(pix
els)
100
1000
10,000
100,000
32x32
128x32
256x64
8x8
USD_32x32
10 9 photons/sec10 7 photons/sec10 5 ph/sec
Saturation Flux = 10 11 photons/sec
NbN?
• Low PRF (<< 1 MHz)– High peak power– Background rejection– Large pixel count– Most LADAR applications
• High PRF (> 1 MHz) – Average power (energy on
target)– Modest background rejection– Smaller pixel count– Most LaserCom applications
PRF = Pulse Repetition FrequencyROIC = Read-Out Integrated Circuit
Two styles of ROIC design: Fabricated ROIC Planned ROIC
Mapping LADARMapping LADAR
Other LADAROther LADAR
LaserComLaserCom
MIT Lincoln LaboratoryVerghese_AFRL101906-26S. Verghese 10/19/06
Dual 128x32 ROICs in MLCD package
• Two overlapping 128x32s (50-um pitch)
MIT Lincoln LaboratoryVerghese_AFRL101906-27S. Verghese 10/19/06
InP APDs: Summary
• We built and demonstrated integrated InP APD arrays for LaserCom and LADAR
– InGaAsP/InP for 1.06-um wavelength
– InGaAs for 1.55-um wavelength (less mature)
• Current focus:
– Increasing Photon Detection Efficiency
– Decreasing Dark Count Rate
• Hybrid-assembly of InP arrays with Si CMOS enables:
– High fill-factor photon counters (up to 4kpixels)
– Compact, low-power sensor (plugs into a pc board)
MIT Lincoln Laboratory
Verghese_AFRL101906-28S. Verghese 10/19/06
End
S. Verghese
MIT Lincoln LaboratoryVerghese_AFRL101906-29S. Verghese 10/19/06
Receiver Development Example (MarsCom)
Physics
System Analysis
Mars
InGaAs Growth
InP waferfabrication
APD design& modeling
MLCD Program Office
Candell, BorosonLDES
1.06-um test-bed1.55-um test-bed
Wafer-probePackage, TestCMOS, PCB
Mar
s L
aser
Co
m—
LD
ES
Div8
G83
G83
Div6,9
Hopman, Hamilton
Duerr, McIntosh, Hopman
SmithDonnelly
Epi Vendor
PhotodiodeVendor
Contract Mfg
System Integrator
IndustryMIT-LL
Oakley, Vineis