Dr Renato Turchetta Instrumentation Department CMOS Monolithic Active Pixel Sensors (MAPS) for the ILC.

Dr Renato Turchetta

Instrumentation Department

CMOS Monolithic Active Pixel Sensors(MAPS) for the ILC

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OutlineIntroduction on MAPS

MAPS for Particle Physics

Parametric test sensors RAL_HEPAPS

Source results

Irradiation results

Flexible APS (FAPS) for ILC. Concept and

source results

MAPS for ILC

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CMOS (Monolithic) Active Pixel Sensor (MAPS)

Standard CMOS technology

all-in-one detector-connection-

readout = Monolithic

small size / greater integration

low power consumption

radiation resistance

system-level cost

Increased functionality

increased speed (column- or

pixel- parallel processing)

random access (Region-of-Interest

ROI readout)

Column-parallel ADCs

Data processing / Output stage

Rea

dou

t co

ntr

olI2

C

con

trol

(Re)-invented at the beginning of ’90s: JPL, IMEC, …

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CMOS sensors: camera architecture

Column-parallel ADCs

Data processing / Output stage

Column-parallel ADCs

Data processing / Output stage Cam

era

con

tro

l

Rolling shutter Snapshot

Integration (exposure) and readout are interleaved

Integration time given by time between two readouts

Simultaneous integration for all pixels, followed by the readout

Cam

era

con

tro

l

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Metal layers

Polysilicon

P-Well N-Well P-Well

N+ N+ P+ N+

CMOS for

100%

efficient

detection

of charged

particles

Dielectric for insulation and passivation

Radiation

--

--

--

- ++

+++

++

- +- +- +

P-substrate

P-epitaxial layer

Potential barriers

epi

sub

N

Nln

q

kTV

Concept first proposed in 1999, and published in NIM in 2001 (R. Turchetta et al.)

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MAPS for Particle Physics and Space Science

2-year PPARC (PPRP) funded programme to develop the underpinning

technology. Started June 2003. Total funding of £300k over 2 years.

5 institutes:

University of Liverpool HEP

University of Glasgow HEP

University of Leicester SS

University of Birmingham SS

CCLRC-RAL with 3 departments: Instrumentation, Space Science and Particle

Physics

4 axes.

1) Pixel architecture: noise, analogue memory, data sparsification

2) Radiation resistance

3) Backthinning: for EUV detection and minimise material for HEP

4) Large area sensor

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Basic Technology MI-3 consortiumConsortium of 11 institutes http://mi3.shef.ac.uk.

Goal: underpinning technology. University of Sheffield (Department of Electrical and Electronic Engineering) University of Liverpool (Semiconductor Detector Center) University of Liverpool (Lab. For Environmental Gene Regulation) University of Glasgow (Particle Physics Experimental Group) University of Brunel (Imaging for Space and Applications) University College, London (Radiation Physics) Institute for Cancer Research (Royal Marsden Hospital) University of Surrey (Centre for Vision, Speech and Signal Processing) University of York (Applied Electromagnetical and Electron Optics Research Group) MRC Laboratoy of Molecular Biology CCLRC-RAL (EID, PPD, SSTD)

Started 7/04 end 7/08

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RAL_HEPAPS family.Sensors for Particle Physics

Sensors Year N. pixel Pitch (m)

Epi layer (m)

Technology

HEPAPS1 2001 8*64=0.5K 15 2 0.25 IBM

HEPAPS2 2003 384*192=73K 15 80.25 TSMC CIS(0.35 in pixel)

HEPAPS3 2004 192*192=36K 15 No0.25 TSMC MM-RF(0.35 in pixel)

HEPAPS4 2005 1024*384=300K 15 >10 0.35 AMS OPTO

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RAL_HEPAPS 2Parametric test

sensor

• 4 pixel types

– 3MOS

– 4MOS

– CPA (charge amp)

– FAPS (10 deep pipeline) R

ow d

ecod

er/c

ontr

ol

3MOSdes. A

3MOSdes. B

3MOSdes. C

3MOSdes. D

3MOSdes. E

3MOSdes. F

4MOSdes. A

4MOSdes. B

4MOSdes. C

4MOSdes. D

4MOSdes. E

4MOSdes. F

CPAdes. A

CPAdes. B

CPAdes. C

CPAdes. D

FAPSdes. A

FAPSdes. B

FAPSdes. C

FAPSdes. D

FAPSdes. E

Columnamplifiers

Column decoder/control

• 3MOS & 4MOS: six different design

each of 64x64 pixels at 64x64, 15m

pitch, 8m epi-layer MIP signal

~600 e-

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Soft and hard resetRESET

ROW_SELECT

Output

Diode

Reset (or kTC) noise is generally the dominant noise sourceVreset

Hard resetRESET – Vreset > Vth for reset transistor

Noise (ENC in e- rms)

Soft resetRESET ~ Vreset.A factor of ~2 reduction noise < 20 e- rms

Noise (ENC in e- rms)

Measured noise distributions for a 64x64 pixel test structure.

Not corrected for system noise

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HEPAPS2: Some Clusters

Number of pixels in a “3x3” cluster

Cluster in S/N

Source (Ru106) test results. Test made in Liverpool.

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HEPAPS2:

Landau

distributions

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RAL_HEPAPS2 3&4 MOS summary

• All 12 substructures are working.• 2 had initial problems in fabrication, and no time yet to test them with MIPs.• The 3 structures with 4MOS-GAA have S/N too low for efficient use for MIP detection.• All the 7 others display good S/N for MIP detection.• Test beam just finished (results now to be analysed):

– Seed cut determines S/N result– Efficiency, global and as a function of impact point

Type Specs S N S/N

3MOS E 4 diodes 99±1 4.94±0.02 20.1 ±0.3

3MOS C GAA 87±2 4.85±0.02 18.0 ±0.4

3MOS B Diode 1.2x1.2 92±1 3.87±0.01 23.8 ±0.2

3MOS A Diode 3x3 67±1 3.31±0.01 20.3 ±0.3

4MOS C Lower VT 101±2 4.14±0.02 24.4 ±0.4

4MOS B Higher VT 114±2 4.70±0.02 24.2 ±0.4

4MOS A Reference 111±2 4.45±0.02 25.0 ±0.4

8 m epi layer

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Radiation test. Source results

• Noise seems to

increase slightly with

dose.

• Signal decreases with

dose.

3MOSA 3x3 m2

3MOSB 1.2x1.2 m2

3MOSC GAA

3MOSE 4 diodes

4MOSA Reference

4MOSB Higher VT

4MOSC Lower VT

J. Velthuis (Liv)

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S/N dependence on impact point.

1015

No rad1014

No rad

4-diode15 m pixel

G. Villani (RAL-PPD)

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Radiation test. Summary

• Sensors yield reasonable S/N up to 1014 p/cm2 (device simulation confirms)

– No efficiency measurement; need testbeam data• 0.35 m technology in the pixel transistors. Enclosed layout in 3MOS_C• Especially 3MOS_E (4 diodes) looks interesting

– Larger capacitance yields larger noise– Four diodes: less dependence of S/N on impact point– After irradiation remains a larger “sensitive area”

!

-

+

+ J. Velthuis (Liv)

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Flexible Active Pixel Sensor

10 memory cell per pixel

28 transistors per pixel

20 m pitch

40x40 arrays

Design for the Vertex detector at the International Linear Collider

Pulses LED test

Light pulse

Amplitude

Time

RAL, 16/2/2005

CMOS sensors for the linear collider50 mm

Readout direction

Red line: control electronics (sampling and readout). Minimal space.

Red rectangle: readout electronics (column amplifiers + ADC + sparsifying circuit) Either on same substrate or bump-bonded to sensor substrate

Ladder with 1 (2) sensor(s)Sensor size: 100 mm *13 mm, read out at both sidesNumber of pixels per sensor: 2500 x 650In each pixel: 20 samples

For ILC: sample at 50 s during beam-on periods and store 20 samples in the pixelColumn parallel readout between trains on multiple lines @ 1 MHz a few ms read-out time

50 mm

13 mm

Minimize budget material in the central area

Keep power dissipation evenly spread and low

Keep sensor architecture simple and adaptable to

machine choice

Simplify system design

Guidelines

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FAPS source test

• Correlated Double Sampling readout (subtract Scell 1)

• Correct remaining common mode and pedestal

• Calculate random noise– Sigma of pedestal and common

mode corrected output• Cluster definition

– Signal >8 seed– Signal >2 next

• Note hit in cell i also present in cell i+1.

• S/Ncell between 14.7±0.4 and 17.0±0.3

Seed 3x3 5x5

J. Velthuis (Liv)

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FAPS Hit resolution

• Take hits found in cell 2• Reconstruct x and y each

cell using Centre-of-Gravity• Calculate average hit

position• Determine residual position

for each memory cell• Hit resolution approximately

1.3 m• Hit Resolutionspatial

resolution!!!

J. Velthuis (Liv)

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FAPS efficiency estimate• Find hits in all cells• Plot max S/Npixel in 3x3 area

around expected hit position if hit not found

• Define:

• Clearly, strongly dependent on seed cut. Lowering seed cut to 5 yields inefficiency ranging between 0.08±0.08% and 0.5±0.1%

1)-(i cell seeds#

cut seedmissed#Missed

J. Velthuis (Liv)

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MAPS plan

Design:

Phase 1: dedicated run with several test structure for FAPS: simulation and test

results to analyse effects of storage cell size, numbers, read-out speed

Phase 2: non-stitched 2 cm x 2 cm uniform sensor

Phase 3: full size, stitched layer 1 sensor

Mechanical mounting: CVD diamond

Readout ASIC. ‘Alignment’ to CCD/ISIS readout cost saving

Explore possibility of sharing technology (ISIS, readout circuit) cost saving.

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MAPS under LCFI

Groups involved: Liverpool, Glasgow, RAL-EID, RAL-PPD (?)

3 runs to XFAB ~ £200k ( Jazz025 ?)

CVD diamond ~£40k

PCB ~ £20k

DAQ ~ £10k

Design effort (RAL EID): about 3.8 SY. Cost £250k (to be discussed within MI-3)

Technician in Liverpool (50% over 5 years): £75k

Some effort from RA already requested within LCFI

RAs from rolling grants in Liverpool and Glasgow

Total cost: ~£600-700k