Summary of CMS 3D pixel sensors R&D Enver Alagoz 1 On behalf of CMS 3D collaboration 1 Physics Department, Purdue University, West Lafayette, IN 47907-2036.

Summary of CMS 3D pixel sensors R&D

Enver Alagoz1

On behalf of CMS 3D collaboration1Physics Department, Purdue University, West Lafayette, IN 47907-2036 US

US CMS Meeting, Colorado-Boulder, 18 May 2012

• 3D vs planar• 3D sensor layouts• 3D assembly• 3D pixel sensors tests

– Lab test results– Beam test results

• Irradiation• Post-irradiation tests

– Lab test results– Beam test results

• Summary & outlook

Outline

2

3D vs planar

ionizing particle

300µm

n+

p+

e

h

depletion

p-type

p+ n+

50µm

p-type

depletion

PLANAR: 3D:

• p+ and n+ electrodes are arrays of columns that penetrate into

the bulk

• Lateral depletion

• Charge collection is sideways

• Superior radiation hardness due to smaller electrode spacing: - smaller carrier drift distance - faster charge collection - less carrier trapping - lower depletion voltage

• Higher noise

• Complex, non-standard processing

3

3D layouts (200 µm substrate thickness)4E Configurationn+ (readout) p+ (bias)

100

μm

150 μm

2E Configuration

1E Configuration

SIN

TEF

3D

(20

0 μ

m th

ick)

CNM

3D

(20

0 μ

m th

ick)

FBK

3D (2

00 μ

m th

ick)

Sin

gle-

side

etc

hing

Dou

ble-

side

etc

hing

Dou

ble-

side

etc

hing

4

Lab test setups• Sensors bump bonded to PSI46v2 ROC in SELEX/IZM (In/PbSn bumps)• Wire bonded and assembled on FPIX plaquettes/testboards• PSI test setup is used to fully calibrate FBK sensors in lab

• ROC calibration• Noise• Charge collection with Sr-90 source

Purdue lab warm test setup Purdue cold test setup

5

3D Plaquettes/testboards

SensorROC

Bump bonds

VHDIBase

plateAdhesive

Wire

bond

Bias wire SIN

TEF

3D FBK

3D

CNM

3D

6

IV measurements @ 21 °C SINTEF 3D

FBK 3DCNM 3D

Breakdown voltages:

CNM > 100V

SINTEF > 100

FBK < 40V

7

Noise scans @ 21 °C

Unable to measure noise at Vbias < 40V for 4E sensors from SINTEF 3D

4E2E

1E

SINTEF 3D

FBK 3D

• Planar FPIX/BPIX noise

~ 100-150 electrons• 3D sensors are

noisier 8

Charge collection @ 21 °C • Sr-90 source: 1 mCi, Eβ = 0.546 ΜeV• Random trigger used

Landau convoluted Gaussian fit

1 Vcal = 65 e- MP = 14 ke-

SINTEF 3D

FBK 3D

9

FBK (200 μm thick)

BEAM

CONTROL ROOM

DUT

PIXEL DETECTORS

SCINTILLATORS

3.7V POWER SUPPLY

ACELLERATOR CLOCK

CLOCK AND TRIGGER

DISTRIBUTION

FNAL testbeam• 120 GeV protons• No B field

Meson Area

10

Beam test results

Telescope alignment with the Monicelli software developed by Milano Uni. collaboration

11

Beam test results

Beam spot 93.4% efficiency

Unirradiated sensors

Beam spot 98.5% efficiency

CN

M 3

DV

bias

= -

15V

: 0

o til

t

FB

K 3

DV

bias

= -

15V

: 0

o til

t

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• Irradiation at the Los Alamos Neutron Science Center (LANSCE) with 800 MeV protons/cm2

– Fluences: 3.5E14, 0.7E15, and 3.5E15 neq/cm2 (FBK)

– Fluences: 0.7E15, and 3.5E15 neq/cm2 (SINTEF)

– Fluences: 1E14, 3E14, 5E14, and 0.7E15 neq/cm2 (CNM)• Post-irradiation lab (@ Purdue) and beam tests (@ FNAL)

performed for SINTEF and FBK 3D sensors– CNM sensors only tested in testbeams

• All readout chips work after irradiation– Except SINTEF case: 1 out of 6 ROCs worked

• Post-irradiation lab measurements carried out in the thermal chamber running at -20 °C – sensor temp estimated by an IR camera to be -7 °C

Irradiation

13

Irradiation: IV tests @ -20 °C SINTEF 3D

FBK 3D

• SINTEF 3D breakdown improved by 15V

• FBK 3D breakdown improved by less than 10V

14

Irradiation: Noise tests @ -20 °C SINTEF 3D

FBK 3D

• SINTEF 3D noise degraded by less than 50 electrons

• FBK 3D noise degraded by less than 50 electrons

15

Irradiation: Charge collection @ -20 °C

Signal LOSS in FBK 3D (@ -30V):

1E 43% after 1E15 p/cm2 (0.7E15 neq/cm2)1E 50% after 5E15 p/cm2 (3.5E15 neq/cm2)

2E 14% after 1E15 p/cm2 (0.7E15 neq/cm2)4E 14% after 1E15 p/cm2 (0.7E15 neq/cm2)SINTEF (200 μm thick)

FBK (200 μm thick)

• Sr-90 source: 1 mCi, Eβ = 0.546 ΜeV• Random trigger used

16

Irradiation: Beam test resultsC

NM

(@

-80

V)

FB

K (

@ -

30V

)S

INT

EF

(@

-80

V)

p+

n+

1E

2Ep+

n+

4E p+

n+

• electrodes are less sensitive: observed lower efficiency on electrode regions

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Summary & outlook

• 3D sensors have several features outperform planar sensors• Sensors received from SINTEF (Norway), FBK (Ital), and CNM (Spain)-Lab characterization tests done at Purdue• Breakdown voltage: SINTEF > 100V, CNM > 100V, and FBK < 40V• 3D sensors have higher noises vs CMS planar sensorsTestbeams carried at FNAL • All efficiencies are higher than 90%Irradiation performed at Los Alamos (800 MeV protons/cm2)• Irradiated fluences are between 1E14 and 3.5x1015 neq/cm2

• Signal loss in FBK 3Ds is lower (14%) for sensors with more than 1 electrodes

Next:• Expecting 3Ds from SINTEF without support wafer• Expecting 3Ds with 1E,2E, and 4E configurations from CNM• Next irradiation fluences will go up to 1E16 neq/cm2

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Czech Technical University, Fermilab, Purdue University, INFN Turin, SINTEF, SLAC, University of Hawaii, University of Manchester

3DC

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BACKUP SLIDES

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Noise tests @ 21 °C Single pixel SCurve

2D noise map

Noise distributionError function fit

Gaussian fit

Higher noise due to long pixel on the sensor edges

Noise measurement of FBK 1E type 3D sensor

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