Advanced Imager Technology
Development at MIT Lincoln
Laboratory
Vyshnavi Suntharalingam
vyshi@LL.mit.edu
Barry E. Burke, James Gregory, Robert K. Reich
MIT Lincoln Laboratory
Detectors for Astronomy, ESO Garching
12-16 October 2009
MIT Lincoln Laboratory
ESO-DFA-1
VS 10/13/09
The MIT Lincoln Laboratory portion of this work was performed in part under a Collaboration Agreement between MIT Lincoln Laboratory and University of
Hawaii (Pan-STARRs), sponsored in part by NASA, and the Air Force 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.
Outline
•
Overview of MIT-LL X-ray, visible to NIR imaging technology
– Tiled CCD Imagers for astronomy
– Devices for adaptive optics
– Back-illumination processes
•
Next-generation technologies
– Stitched large-format, small-pixel CCDs
– Four-side abuttable CCD and 3-D CMOS image sensors
•
ESO-DFA-2
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Summary
MIT Lincoln Laboratory
Imaging Devices at MIT Lincoln Laboratory
Program Areas
Space- and Ground-based
Surveillance and Scientific Imagers
Silicon Photon
Counting Arrays
High-Speed Imaging
• Curved CCDs
• Orthogonal Transfer Arrays
• High-speed camera electronics
• High-fill-factor APDs
• Large-format, small-pixel
• CMOS ROIC for photon counting • CMOS x-ray sensor
imagers
• Single-electron sensitive readout • Multi-sample CCD
Technology Elements
Detector Design
ESO-DFA-3
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Silicon Detector
Process Development
Advanced Packaging
Electronics
MIT Lincoln Laboratory
Microelectronics Facility Upgrade
to 200-mm Silicon Wafer Size
•
Three-year capability upgrade in progress
– First 200-mm device lots beginning Feb. 2011
•
Nine CCID-20s on a 200-mm wafer
– 15-m pixel, 2K x 4K, 32mm x 63mm
CCID-20
CCID-20
illustration
100-mm wafer
Two devices (2K x 4K)
ESO-DFA-4
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150-mm wafer
Six devices
200-mm wafer
Nine devices
MIT Lincoln Laboratory
Tiled CCD Imagers for Astronomy
12-CCD UH/CFHT FPA
100Mpix
60 Orthogonal-Transfer CCDs
Pan-STARRs (3° WFOV)
1.36 Gpixels
Image from First Light
(August 2007)
1.2 mm
200 m
ESO-DFA-5
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MIT Lincoln Laboratory
Lincoln Laboratory High-Speed CCDs
for Adaptive Optics
1985
1990
1995
2000
2010
2005
First AO devices
6464,
4 ports
128128,
16 ports
Electronic
shutter
ESO-DFA-6
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256256,
32/64 ports
(in design)
CCD for
curvature
wavefront
sensing
160160,
20 ports;
pJFET sense
amplifier
Polar-coordinate
imager
(in design)
CCD and
camera electronics
MIT Lincoln Laboratory
Amplifier read noise
(rms electrons)
Performance of pJFET-based Output Circuit
Output Data Rate (MHz)
Noise: pJFET vs. nMOSFET
ESO-DFA-7
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MIT Lincoln Laboratory
Output Circuit Comparison
Sense-node capacitance is lower
(higher responsivity) for JFET
than MOSFET
ESO-DFA-8
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Noise spectral voltage is lower
for JFET than MOSFET
MIT Lincoln Laboratory
Back Illumination Processes
MBE and Laser Anneal (IILA)
External QE
MBE Delivers Reflection-Limited QE
0.8
0.7
Reflectance Limit
0.6
0.5
MBE
No ARC
here
0.4
0.3
0.2
Room Temperature (20°C) Result
60-sec Integration Time
Wafer-level Image
of Buckman Tavern
Front Illuminated
0.1
200
Dark Current (A/cm2)
1.E-08
300
400
500 600 700 800
Wavelength (nm)
900 1000 1100
MBE backside dark current 10x better than IILA
Clock dithering can suppress front interface states (IS)
1.E-09
1.E-10
1.E-11
Vignetting from test setup
1.E-12
IILA-IS
ESO-DFA-9
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IILABack
MBE-IS MBE-Bulk Estimated MBE& Back
Bulk
Back
Dark Current Sources
MIT Lincoln Laboratory
Outline
•
Overview of MIT-LL X-ray, visible to NIR imaging technology
– Tiled CCD Imagers for astronomy
– Devices for adaptive optics
– Back-illumination processes
•
Next-generation technologies
– Stitched large-format, small-pixel CCDs
– Four-side abuttable, 3-D CMOS image sensors
•
ESO-DFA-10
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Summary
MIT Lincoln Laboratory
Deeply Scaled CCD Process Technology
• Small pixels, low-voltage, CMOScompatible operation
• Demonstrated small-array CCDs
– Simplified single and two poly
fabrication
– Reduced pixel dimension (8-, 5-, 2-μm)
– ~150,000 e- well capacity for 8-μm
pixel at 3V
8-μm
pixel
Two Poly OTCCD
10μm
5-μm
pixel
Single Poly OTCCD
• Current efforts: Apply to large area
devices
10μm
– Deep ultraviolet photolithography for
submicron features (pixel sizes to 2
m)
– Stitching for large format imagers
2-m
pixel CCD
10μm
ESO-DFA-11
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MIT Lincoln Laboratory
Large-Format, Modular CCD Imagers
•
•
Example: 3K x 3K OTCCD image sensor with 8m x 8m pixels
Pixels with submicron dimensions require high-resolution (248-nm) patterning
–
•
Lithography field size is smaller than device size
Design is fractured into functional blocks onto a multi-field reticle and precisely
stitched back together on wafer
Design Concept
ESO-DFA-12
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Layout Fractured
Functional Blocks
Multi-field Reticle
Reassembled Design on Wafer
MIT Lincoln Laboratory
Completed 3K x 3K OTCCD Devices
•
•
•
•
Large-area devices (26 mm x 50 mm)
fabricated with low-voltage CCD
technology
Stitching methods achieve 35nm (3)
precision with 8-m pixel active devices
Device test results expected in Dec.
2009
Process technology will be migrated to
200-mm substrates
150 mm
Stitched
Boundary
dual poly
OT Image Array
single poly
Frame Store
Reference Image
(No Stitching Required)
Poly-1
gate
channel
stop
300 nm
300 nm
8m
1m
1m
Stitch boundary
ESO-DFA-13
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MIT Lincoln Laboratory
Four-Side Abuttable 3-D CMOS Image
Sensor Development
Addressing
Conventional Monolithic
CMOS Image Sensor
3-D Pixel
Light
PD
pixel
PD
3T
pixel
ROIC
Processor
Addressing
A/D, CDS, …
•
•
•
•
ESO-DFA-14
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Pixel electronics and
detectors share area
Fill factor loss
Co-optimized fabrication
Control and support
electronics placed outside of
imaging area
•
•
•
100% fill factor detector
Fabrication optimized by layer
function
Local image processing
– Power and noise management
•
Scalable to large-area focal
planes
MIT Lincoln Laboratory
Oxide-Bonded 3D-I Technology
•
•
Smaller pixels than bump bonding
100% Fill Factor for Back Illumination
Center of Pixel Array
Tier-2
Readout
SOI Transistor
3-D
Via
Oxide Bond
Tier-1
Detector
50m thick
10m
ESO-DFA-15
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Single
8-m
pixel
MIT Lincoln Laboratory
Example 3D Imager Demonstrations (1)
Two-Tier, CMOS Image Sensor
1024x1024 Array, 8-μm pixel
Three-Tier, GmAPD Laser Radar
64x64 Array, 50-μm pixel
10μm
Completed Pixel Cross-Sectional SEM
3D
Via
Transistors
Back Illum. Chip
Photomicrograph
Tier-3: 1.5V SOI CMOS Layer
3D
Via
Transistors
Tier-2: 3.5V SOI CMOS Layer
8μm
Tier-1: 30V Back Illuminated APD Layer
Target:
Cone and Support Post
Captured Range
Image
In Front of Flat Plate
Shadow
Tier-3
Wafer-probe-leveltest
test
Wafer-probe-level
Off-chip
A-to-D
Off-chip A-to-D
Mockup Tile
with ADC Chip
ESO-DFA-16
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-6
8 mm
IEEE ISSCC 2005
IEEE ISSCC 2006
+3
3 feet
MIT Lincoln Laboratory
Example 3D Imager Demonstrations (2)
Seven-Tier, Four-side Abuttable CMOS APS
1024x1024 Array, 8-μm pixel
Two-Tier, InGaAs Detector
8-μm pixel
Pixel Cross-Sectional SEM
~70μm
SOI
readout
Tier-2: 3.5V SOI CMOS Layer
3D
via
8μm
Tier-1: InGaAs PIN diode (epi)
64-ch ADC
10 μm
InP substrate
Photo-response in PIN diode current
Fe55
Captured Image at 10fps
X-ray histogram
2
(companion two tier sensor)
200
Current (μA)
Counts
300
12.6 electrons
noise
180 eV
100
From temporary support
IEEE ISSCC 2009
ESO-DFA-17
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0
20
40
60
80
Signal (mV)
IEEE Trans. Elec. Dev.2009
100
1
0
Dark
-1
-2
-2.0
Light
-1.5
-1.0
-0.5
0
0.5
IEEE
3DIC 2009
MIT Lincoln Laboratory
Bias (V)
Summary
•
Lincoln Laboratory develops tiled CCD imagers with novel
architectures for astronomy
– First gigapixel focal plane successfully deployed
•
New device and process improvements continue to increase
responsivity and reduce dark current
•
Next-generation imagers in development
–
–
–
–
Small pixel, large format, four-side abuttable devices
CCD and CMOS-based detectors
Back-illuminated, 100% fill factor, 3-D integrated image sensors
Advanced package development for higher data rate, tiled
image sensors
MIT Lincoln Laboratory
ESO-DFA-18
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Acknowledgments
Design
Microelectronics Lab
Microelectronics Lab
Brian Aull
Bob Berger
Chang-Lee Chen
Michael Cooper
Brad Felton
Kay Johnson
Keith Percival
Dennis Rathman
Bruce Wheeler
Doug Young
Andy Loomis
Chenson Chen
Jeff Knecht
Donna Yost
Kevin Newcomb
Keith Warner
Dave Astolfi
Vladimir Bolkhovsky
Ken Belanger
Desi Biasella
Laurie Briere
Marc Brunelle
John Burke
Joe Ciampi
Jeff Decaprio
Diane DeCastro
Charlie Doherty
Pascale Gouker
Yvette Grinbush
Paul Healey
Bob Healey
Denise Holohan
Sal Ieni
John Jarmalowicz
Scott Ladd
Renée Lambert
Debbie Landers
Jim Lawless
Jamie Mongiello
Chuck Monoxelos
Alan O’Dea
John Pentoliros
Segundo Pichardo
Joe Powers
Sandra Roy
Angel Reinold
Dolly Shibles
Chris Weinberg
Peter O’Brien
Wendy Ruth
T.J. Wlodarczak
C. Keast (Solid State Div.)
D. Shaver (Solid State Div.)
Testing
Harry Clark
David Craig
William McGonagle
Dan O’Mara
Tony Soares
ESO-DFA-19
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MIT Lincoln Laboratory
Backup
ESO-DFA-20
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MIT Lincoln Laboratory
Tile Block Diagram
•
•
•
•
•
Vertically stacked
Pixel readout on Tier-2
Timing control in Stack
64-ch 12-b pipelined
ADC
Digital output
ESO-DFA-21
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Light
MIT Lincoln Laboratory
Finished Tile Stack Appearance
Back Illuminated
3-D CMOS Imager
1024 x 1024 pixels
8.3 x 8.3 μm2 pixel
64 analog outputs
Programmable Digital Imaging Tile
~70μm
5 layer stack
64 A/D converters
Timing & Control
1024x1024 pixels
>1 Million vias
144 gold stud bumps
2 x 96 side bus lines
88 POGO pins
ESO-DFA-22
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MIT Lincoln Laboratory