Design and process development of CMOS image sensors with ... · Amos Fenigstein, Assaf Lahav,...
Transcript of Design and process development of CMOS image sensors with ... · Amos Fenigstein, Assaf Lahav,...
CPIX14Workshop on CMOS Active Pixel Sensors for Particle Tracking
Bonn University15‐17 September 2014
Design and process development of CMOS
image sensors with TowerJazz
Dr Renato Turchetta
Rutherford Appleton Laboratory (RAL)Oxfordshire, UK
E-mail: [email protected]
Jamie Crooks, Nicola Guerrini, Iain Sedgwick, Dipayan Das, Bindu
Velagapudi, Ben Marsh, Giulio Villani, Steve McMahon (STFC-RAL)
Amos Fenigstein, Assaf Lahav, Tomer Leitner, Adi Birman
(TowerJazz Semiconductor)
Wai Chan, Keith Taylor (Specialised Imaging)
Mark Brouard, Claire Vallance, Richard Nickerson, Andrei
Nomerostki, JayaJohn John et al. (Oxford University)
… and many others
Acknowledgments2
Deep P-well PImMS: example of a Hyper Active Pixels Sensor (HAPS) Kirana: CCD-in-CMOS for ultra-high speed imaging CMOS sensors for Atlas tracker Conclusion
3 Outline
Deep P-well PImMS: example of a Hyper Active Pixels Sensor (HAPS) Kirana: CCD-in-CMOS for ultra-high speed imaging CMOS sensors for Atlas tracker Conclusion
4 Outline
CMOS Image Sensor for a digital calorimeter at the International Linear Collider Requirements:
Pixel size = 20-60 µmS/N = MIPS detection with a noise hit rate < 10-5 noise ~ 20-30 e- rmsTime stamping with 150 ns resolution (6.7MHz), over 16 bitsLarge area to be covered MAPS sensor …
… but need a HAPS type pixel: HAPS = Hybrid Active Pixel Sensor or Hyper-Active Pixel Sensor
STFC patent on the deep P-well: how to integrate CMOS electronics in a pixel without compromising performance
Which foundry? Start working with Tower Semiconductor in 2006 to develop a
deep P-well module
Introduction5
NMOS
P-Well N-Well P-Well
N+ N+
P-substrate
N+ N+
Diode NMOS
--
- +++
- +P-epitaxial layer
Passivation layers and routing (SiO2 + metal) A few μm
~1 μm
up to a few tens of μm
A few hundred μm
Sensitive volume
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N-Well
P+ P+
PMOS
Particle detection in CMOS
NMOS
P-Well N-Well P-Well
N+ N+
P-substrate (~100s m thick)
N+ N+
N-Well
P+ P+
Diode NMOS PMOS
Deep P-Well
Standard CMOS with additional deep P-well implant. Quadruple well technology.
100% efficiency and CMOS electronics in the pixel.
Optimise charge collection and readout electronics separately!
7 Deep P‐well
• Gain 136uV/e• Noise 23e-• Power 8.9uW • 150ns “hit” pulse
wired to row logic• Shaped pulses
return to baseline
• 50um pixel• 4 diodes• 160 transistors• 27 unit capacitors• 1 resistor (4Mohm)• Configuration SRAM
• Per Pixel Mask• Comparator trim (6
bits)
DPWNW
M1PO
8 Image Sensor for Calice
TPAC = Tera Pixel Calorimeter
• Amplitude results• With/without deep pwell• Qualitative comparison
• Simulations “GDS”• Measurements “Real”
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Position in cell (microns)
Profile B; through cell
GDS+DPW
GDS-DPW
Real+DPW
real-DPW
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Position in cell (microns)
Profile F; through cell
GDS+DPW
GDS-DPW
Real+DPW
real-DPW
F
B
Pixel profiles
9 Measured vs Simulation Results
Charge collection
17μmTiming
measurement(30mV threshold)
TCADSimulation
(Q=90%)
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50 60 70 80 90 100
Tim
e de
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(ns)
X Position (microns)
Charge collection time: Measurements vs Simulation
Sim Profile C
Sim Profile B
Measurements
Measured timing includes a fixed laser-fire delay
BC
M
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Deep P-well PImMS: example of a Hyper Active Pixels Sensor (HAPS) Kirana: CCD-in-CMOS for ultra-high speed imaging CMOS sensors for Atlas tracker Conclusion
11 Outline
It stands for Pixel Imaging Mass Spectrometry, a project developing a fast imaging sensor for use in a next-generation time-of-flight mass spectrometer (TOF-MS) with unique imaging capabilities
Specifications fairly close to the ones of the TPAC sensor
Needs spatial and time resolution
http://pimms.chem.ox.ac.uk
PImMS12
PImMS
PImMS – Pixel Imaging Mass Spectrometry
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PImMS pixel layout
Over 600
transistors
Modified process
developed with
TowerJazz: deep P-
implant for 100%
fill factor and true
CMOS
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PImMS1
72 by 72 pixel array
PImMS2
324 by 324 pixel array
PImMS family
70 μm x 70 μm pixel size
Time-code resolution= 12.5 demonstrated
4 event stored in each pixel
12 bit time-code resolution
Analogue readout of intensity information
With a conventional imager, same performance achieved by taking
4,096 frames at 80 million frames per second
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Perpendicular 1D alignment and Coulomb explosion imaging
Coulomb explosion imaging
Neutron tomography
Deep P-well PImMS: example of a Hyper Active Pixels Sensor (HAPS) Kirana: CCD-in-CMOS for ultra-high speed imaging CMOS sensors for Atlas tracker Conclusion
18 Outline
(Ultra)‐High speed imaging19
Frame rate (fps)
Reco
rd le
ngth
(fra
mes
) The camera resolution
is proportional to the
shaded area
CCD in CMOS technology
CMOS for ease of use and readout speed
CCD for in-pixel storage
Start from Tower 180 nm CIS process with
dual gate oxide: 3nm + 10nm
Optimise process for high-speed, high-
efficiency charge transfer
Developed by STFC with TowerJazz, see SPIE Digital Imaging 2013,
IISW 2013
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Sensor requirements
Ultra-high speed (>1MHz) with high frame
depth (~200 cells)
High resolution (~Megapixel)
High-speed (~kfps) for continuous readout
10 bit resolution
Flexible trigger (pre/post/center)
35mm format
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Charge storage
Photodiode
Memory bank- A vertical entry (VEN)
bank with 10 cells- Ten rows of lateral (LAT)
banks, each with 16 cells- A vertical exit (VEX) bank
with 10 cells
VEN
Photodiode
VEX
LAT
N+ Guard ring
Deep P-implant
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A. Lahav, J. Crooks, B. Marsh, R. Turchetta, A. Fenigstein, “CMOS Image Sensor Pixel with 2D CCD Memory Bank for Ultra High Speed”, ISSW 2013
Diode.
‘W effect’ W1 W2
W1
W2
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CCD in CMOS
Single poly process
Poly space: 250 nm
3-phase CCD
10nm thick gate oxide
Buried channel under gates
P-implant
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Kirana pixel
Highly scalable architecture:- Number of memory cells- Number of pixels
- Low power
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Kirana. Burst mode26
Kirana. Continuous mode27
Performance summary
Parameter Unit ValuePixel pitch (X) um 30Pixel pitch (Y) um 30
Pixel format (X) 924Pixel format (Y) 768Number of pixels 709,632
Frame rate (burst mode) fps 5,000,000Frame rate (continuous mode) fps 1,180
Pixel rate (burst mode) Pixel/sec 1.42 TPixel rate (continuous mode) Pixel/sec 0.84 G
Noise e- rms <10 e- rmsFull well capacity e- 11,700
Camera gain µV/e- 80Dynamic range >1,170
dB 61.4bit 10.2
Fill Factor 11%
Quantum efficiency Without microlens
2.3% (red)2.2% (blue)
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High resistivity silicon
Microlenses
Stress in steel rod29
Longer video on YouTube: “Ultra high speed imaging of fracture”
Daniel Rittel, Dynamic Fracture Lab.
www.youtube.com/watch?v=ERhvhWogysw
Glass breaking30
5 millions fps31
Pixel rate in Image Sensors
PImMSKirana
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Deep P-well PImMS: example of a Hyper Active Pixels Sensor (HAPS) Kirana: CCD-in-CMOS for ultra-high speed imaging CMOS sensors for Atlas tracker Conclusion
33 Outline
Rad‐hard sensors34
Goal: to achieve radiation hardness in excess of 100Mrad and 1015 n cm-2
Can we use CMOS Image Sensor technology?
Different types of diodes, several options for starting material, flexibility in MPW running, stitching, …
… but needs fully depleted CMOS and backbias to counteract change in resistivity and trapping
Status35
Work in progress
1st tape out being completed
Different starting material: Resistivity up to 25umHigh resistivity >~ 1kOHm cmP epi on P substrate and P epi on N substrate wafers
Basic TCAD work done on average CMOS conditions
Electric field36
P-epi
N-sub
Deep N-well
P-well
Charge collection. 137
Charge collection. 238
10V backbias and 10um lateral position
15V backbias and 20um lateral position
Deep P-well PImMS: example of a Hyper Active Pixels Sensor (HAPS) Kirana: CCD-in-CMOS for ultra-high speed imaging CMOS sensors for Atlas tracker Conclusion
39 Outline
Start working with TJ 180nm CIS in 2006
Deep P-well implant 100% fill factor and full CMOS in the pixel
Hyper/Hybrid Active Pixel Sensor electronics demonstrated in
the PImMS sensor, currently used for TOF MS
High resistivity wafers
CCD-in-CMOS for ultra-high speed imaging
Rad-hard sensors for Atlas tracker: just started the development
… also Single Photon Avalanche Detectors (SPAD, not shown)
and many other sensors (e.g. Percival presentation, tomorrow)
Conclusions40
The world of CMOS (Hyper)Active Pixel Sensor is
very exciting and offers plenty of opportunities.
Come and join us!
Recruiting designers now: e-mail me ([email protected])
or browse jobs in STFC at www.topcareer.jobs
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