KEK Seminar
9 December 2013,
Tsukuba

CMOS Image Sensors atthe Rutherford AppletonLaboratory
and … a bit more
Dr Renato Turchetta
Rutherford Appleton Laboratory (RAL)
Oxfordshire, UK
E-mail: renato.turchetta@stfc.ac.uk

2Outline
 Introduction. STFC and some of its detector activities
 CMOS image sensors for science Large area CMOS image sensor
 Achilles
 Lassena
 Percival Ultra-high speed CMOS image sensors
 PImMS Kirana Conclusion

3

UK Astronomy Technology Centre
Edinburgh

Polaris House
Swindon, Wiltshire

Chilbolton Observatory
Stockbridge, Hampshire

Science and Technology
Facilities Council
Daresbury Laboratory
Daresbury Science and Innovation Campus
Warrington, Cheshire

Rutherford Appleton Laboratory
Harwell Oxford Science and Innovation Campus

Isaac Newton Groupof Telescopes
La Palma4

STFC in the world
International partners
STFC manage the UK contribution to large scale facilities in the world

o CERNo European Southern Observatory ESO
o European Space Agency ESAo European Synchrotron Radiation Facility ESRF
o Institute Laue-Langevin ILLTechnology

5Europractice
softwareSolutions
Facilities

STFCTechnologyTransfer

6Hexitec.
Energy resolving, pixel detector

Hexitec ASIC2cm•80x80 pixels•Energy Range: 4-200 keV•1mm CdTe - 500V Bias
•FWHM@60keV = 0.8 +/- 0.2 keV•(second range 12-600keV)

X-ray

CdTeor CZT
e-number of electrons= X-ray [eV] / 4.2

ASIC
80x80
gold studs

10,000 fps @ rolling shutter

7Hexitec. Next.
Hexitec: K-edge Transmission Imaging

Subtraction toremove backgroundand leave I detailAbsorption of the I in
the tubing and noiseof the non-uniformbackground.

Multimodule, large
area sensor

LPD.
Large Pixelated Detector

8LPD is a high speed (4.5MHz) andhigh dynamic range (105 @ 12keV)
integrating camera system.
Scalable system

Optimum Energy Range
Sensor Thickness
Pixel Size
Dynamic Range at 12 keVInactive area
Max. Frame Rate
Min. Frame Rate
Gain Factors
Storage Capacity
Data Output Rate (Mpix)

5 keV – 20 keV
500 μm500 x 500 μm
51013%
4.5 MHz
1 MHz
10KHz
1x, 10x, 100x
512 x 310GBs

LPD.
Large Pixelated Detector

9Custom ASIC in 130 nm CMOS

Custom DAQ. 10Gbit links

The LPD team during the beam
test at LCLS this year

Custom S/W integrated withmachine S/W

10CMOS Image Sensor
at RAL
N+N+Br+Br+Br+

Large area sensor.
Stitching.

11DBB

DReticle size is just over 2cm x 2cm  ‘stitching’
Reticle is subdivided in blocks
CAA

C

56 mm

reticle limitation  up
to single sensor per

56 mm

CASensor size freed fromwafer

ACSensors of different
sizes can be
manufactured

DB

BD

12Transmission Electron
Microscopy (TEM). Prior art.
Film

 Film: direct detection, very goodresolution, non digital, poor S/N forweak exposure CCD with phosphor:indirect detection(radiation hardness),phosphor ruins spatial
resolution, good for
tomography

4kx4k CCD camera
with phosphor plate

13

CMOS Sensor for TEM
 Direct detection
 Good single electron sensitivity
 Good MTF and DQE
 Radiation resistant 4Kx4K array 16 million pixels

14

Detection of electronsin CMOS

15Achilles.
A 16Mpixel sensor for TEM

 61x63 mm2 silicon area (4 dies per wafer)
 0.35m CMOS
 16 million pixels, 4Kx4K array 14 µm pixels
 32 analogue outputs
 40 fps Pixel binning 1X, 2X and 4X
 ROI readout 83 e- rms noise Full well 120ke Radiation hardness of >500 million of primary electrons/pixel(>20 Mrad) 20% QE for visible light

16

Adenovirus

Courtesy of G. McMullan (LMB, Cambridge, UK)17

Structured scintillators
Mesh in a silicon wafer
filled with CsI‘Artist view’Photograph18

Contrast
Scint A

Scint B
600

Scintillator

CTF at10LP/mm

150

140

550

130

Standard A

18%500

New Bv125um pore
New Bv2
30.8um pore70±10%

450120110

100

55±5%

400

908035017 lpm @ 10%

260

240

All at 120kV and 3W – noise
gives uncertainty to CTF(Contrast Transfer Function)
values.

220200Wafer‐scale sensor for X‐ray
medical imaging

19Motivations

Guidelines

 Extra-oral dental

 Wafer-scale sensor

 with tiling: One sensor per 200 mm wafer

Mammography 3-side buttable  2xN tiling

Chest imaging

 Radiation hard design

Security Design for yield...

20

Main features

 High resolution. 50 µm pixel.
 High-speed. Over 30 frames per second at full resolution.
 Low noise. 68 e- rms in full frame to give very high sensitivity.
 139mmx120mm and 3-side buttable for large area coverage.
 High dynamic range. Multiple programmable integration times
 Binning x2, x4 and Region-Of-Interest (ROI) readout Manufactured in 180 nm CMOS Image Sensor process fromTowerJazz Semiconductor

21

Lassena. Floorplan

To the pixel:
3T pixel base
withLow noise,large partiallypinned diodeBinningcapability

Lassena. A 6.7Mpixel,
wafer‐scale sensor

22

Optical performanceRms electronic noise

Linear full well

Maximum full well

Dynamic range (Linear)

Dynamic range (Maximum)

68

Full resolution mode (i.e. no binning)335

Bin 2x2 mode608

Bin 4x4 mode

112,000

Full resolution mode (i.e. no binning)

1,253,000

Bin 2x2 mode

5,012,000

Bin 4x4 mode

144,000

Full resolution mode (i.e. no binning)

1,374,000

Bin 2x2 mode

5,496,000

Bin 4x4 mode

10.7

Full resolution mode (i.e. no binning)

11.9

Bin 2x2 mode

13.0

Bin 4x4 mode

11.0

Full resolution mode (i.e. no binning)

12.0

Bin 2x2 mode

13.1

Bin 4x4 mode

35

Full resolution mode (i.e. no binning)70

Bin 2x2 mode140Bin 4x4 modee- rmse-e-bits

bits

Readout speed

frames per second

Quantum efficiency

Measured @540nm

Lag

50%
Negligible

OtherPower supply

V3.3

Number of pads

480

All on one side

Power Consumption (mW)

W

<2.5

CMOS only

23Percival

Pixelated Energy Resolving CMOS Imager,
Versatile and LargePercival target
specifications24

 Low energy X-ray detection <~ 2,000 eV
 High efficiency  back-side illuminated and direct detection
 High resolution  4kx4k on a 25µm pitch Good single photon sensitivity  low noise High dynamic range, i.e. up to ~ 2*105 photons @ 250 eV  highdynamic range (HDR) pixel --> ~120dB or full well >10 Me High frame rate  120 fps
 Fully digital

25

HDR pixel

RESET
SW2

SW1SW0

SELECT
C2

C1C0Column

 Based on overflow
capacitors.
 Switches SW0, 1 and 2 areheld ‘almost open’ during
integration

26

Signal path

Pixel

The diode isread first,
then thethreecapacitors

Decision
block

Sampling
stage

It selects thelowest nonsaturatedvalue

This value issampled, as
well as thereset valueMultirampADC

Bothsampledvalue andreset areconverted

ADC conversion over 12 bits. 5 coarse plus 7 fine (plus 1 for overrange)
2 bits for gain, as selected by the decision block27

Percival sensor floorplan

 120 fps (digital CDS)
 High dynamic range (4 gains perpixel) 12+1bit ADC
 15 bits per pixel (2 gain bits + 13bits)
 Digital I/O (LVDS)
 60 Gbit/sec continuous data rate

SPI and bias
generator

 16 MPix resolution

Multi-level row control

Preliminary specifications

Pixel array
4kx4k@25µm pitch)

28,000 ADCs(7 ADCs per column)
Serialiser and LVDS I/O28

Time‐Of‐Flight Mass
Spectroscopy
Requirements• Spatial information• Timing information

Courtesy of M. Brouard, C. Vaillance, R. Nickerson et al., Oxford University

29

PImMS. A single particle CMOS
Image Sensor.
PImMS – Pixel Imaging Mass Spectrometry

30

PImMS pixel layout

Over 600 transistors
per pixel
Modified processdeveloped withTowerJazz: deep Pimplant for 100% fill
factor and true CMOS

31

PImMS family
PImMS1

PImMS272 by 72 pixel array324 by 324 pixel array
70 µm x 70 µm pixel size
Time-code resolution= 25 ns (12.5 demonstrated alreadyon PImMS1)

PIMMS USB camera

4 event stored in each pixel
12 bit time-code resolution
Analogue readout of intensity
information
Equivalent pixel rate for standard full
frame camera

PImMS. First example ofscientific results.

32

N+

N+/Br+ covariance – vertical alignment

N+

NOT

Br+Br+Br+

(Ultra)‐High speed
imaging. Applications

33

High-speed: 1k to 100kfps
Ultra-high speed: >~ 1M fps






Combustion Research
Biological/Microscopy
Ballistics
Mechanics
Cavitation
Material Research
AerospaceDigital Image Correlation
PIV

34(Ultra)‐High speed
imaging review

No existingsolution

35Kirana

 CMOS for ease of use and readout speed
 Start from Tower 180 nm CIS process withdual gate oxide: 3nm + 10nm
 Optimise process for high-speed, highefficiency charge transfer
 CCD for in-pixel storage

36

Kirana pixel. 1
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) bankwith 10 cells- Total of 180 memory cells

37

Kirana pixel. 2Highly scalable architecture:- Number of memory cells- Number of pixels

38

Burst mode
Vertical transfers x10@ full speed

39

Burst mode
Charge moved into
lateral memory bank40

Burst mode
Ten more verticaltransfers

41

Burst mode
Lateral transfer x1@ full speed / 10

42

Burst mode
… and so on,seamless43

Burst mode
… and so on,seamless44

Burst mode
… and so on,
seamless

45

Burst mode
… and so on,seamless46

Burst mode
… and so on,seamless47

Burst mode
… and so on,seamless

48

Burst mode
… and so on,seamless49Burst mode

50

Burst mode
Charge in the vertical exit
registers is dumped in thereset node …

… until receiptof the trigger.
The status ofthe memorybank is thenfrozen and thesensor readout.

51

Continuous mode
Memory bank acting
simply like a delay line

52

Continuous mode
Memory bank acting
simply like a delay line

53

Continuous mode
Memory bank acting
simply like a delay line

54

Continuous mode
Memory bank acting
simply like a delay line

55

Continuous mode
Memory bank acting
simply like a delay line

56

Continuous mode
Memory bank acting
simply like a delay line

57

Continuous mode
Memory bank acting
simply like a delay line

58

Continuous mode
Memory bank acting
simply like a delay line

59

Continuous mode

60

Continuous mode61

Continuous mode

62

Continuous mode

63

Continuous mode

64

Continuous mode

65

Continuous mode

66

Sensor floorplan

Column readout
circuitry.
4 rows are read
simultaneously
96 valid address oneach side; groupedin 3 banks,
individually enabled

CCD drivers (17 lines)
For global shutter
operation
Pixel array:924 columns
768 rows

42 analogue outputchannels@10Mpixel/sec on
each side (88 pixels
per amplifier)67

CCD drivers
Allow multiple level drivers.
Signal range: -1V  6V

68

Diode timing

Shutter speed <~ 60 ns

69Performance summary
Parameter
Pixel pitch (X)Pixel pitch (Y)Pixel format (X)Pixel format (Y)Number of pixels
Frame rate (burst mode)
Frame rate (continuous mode)
Pixel rate (burst mode)
Pixel rate (continuous mode)
Noise
Full well capacity
Camera gain
Dynamic range

UnitumumfpsfpsPixel/sec
Pixel/sec
e- rmseµV/edB
bit

Fill Factor
Quantum efficiency

Withoutmicrolens

Value
3030924
768
709,632
5,000,000
1,180
3.5 T
0.84 G<10 e- rms
11,70080>1,170
61.4
10.2
11%
2.3% (red)2.2% (blue)Firstmanufactured onstandard epi: 5.5µm thickness,
low resistivity.
New, improved
version made on
high-res epi andmicrolenses justreceived frommanufacturing

70

Imaging examples

71

Imaging examples

72… and also
More CMOS image sensors
developed(www.dsc.stfc.ac.uk/cmossensors)
Sensors for Alice at CERN-LHC
Single Photon Avalanche Detector(SPAD) array
Highly Miniaturised Radiation
Monitor (HMRM) for ESA
Terahertz detectors

73

Wrap‐upBroad span of technologies developed at STFC-RAL:
detectors, ASIC, DAQ, software, mechanics, cooling, …
Hybrid detectors: Hexitec, LPD, …
CMOS image sensors: focus on science applications,with efficient transfer to industry
Large area sensors up to wafer-scale: Achilles for TEM
in production, Lassena for medical imaging, Percival
for low-energy X-ray detectors.
Ultra-high speed sensors: PIMMS for mass spec, Kirana
for imaging
and more!

74AcknowledgementsColleagues at the Rutherford Appleton Laboratory:
J. Crooks, D. Das, N. Guerrini, B. Marsh, I. Sedgwick, V. Sooden, B. Velagapudi,
M. Hart, M. French, P. Seller, M. Wilson, V. Perera, P. Booker, …
and at collaborating institutes:
R. Henderson, G. McMullan, W. Faruqi (Laboratory of Molecular Biology,Cambridge)
G. van Hoften (FEI)
M. Brouard, C. Vaillance, R. Nickerson et al. (Oxford University)
W. Chan, K. Taylor (Specialised Imaging)
A. Fenigstein, A. Lahav (TowerJazz Semiconductor)…
See also

www.dsc.stfc.ac.uk/cmossensors

75

The last slide

Questions?
www.dsc.stfc.ac.uk/cmossensors