SiPM technology at FBK - Fermilabdetectors.fnal.gov/wp-content/uploads/2017/09/Piemont.pdfThe SiPM...

SiPM technology at FBK

C. Piemonte

http://srs.fbk.eu www.advansid.com

FBK/AdvanSiD, USA tour 2011C. Piemonte 2

Outline

FBK SiPM technology overview

Development of SiPMs for TOF-PET

AdvanSiD


SiPM technology overview


13

14

15

16

17

18

19

20

0 0.2 0.4 0.6 0.8 1 1.2 1.4

depth (um)

Do

pin

g c

on

c. (1

0^

) [1

/cm

^3

]0E+00

1E+05

2E+05

3E+05

4E+05

5E+05

6E+05

7E+05

E f

ield

(V

/cm

)

Doping

Field

n+ p

Technology characteristics:

1) Integrated polysilicon resistor

2) Very shallow junction to enhance QE at short wavelengths

2) possible ARC to optimize QE at certain wavelengths

p+ subst.

p epi

n+

SJ-SiPM Technology

Cross section

Development started in 2005 in collaboration with INFN


Device Layout: example of internal structure

Metal line connecting

all cells in parallel

(one common anode)

Polysilicon

resistor

Field-plate

to reduce electric

field around the

junction

Resistor is located

around the active

area => no fill factor

loss

The cathode is

contacted on the

rear side.

FF ~ 25% 25x25um2 cell

~ 45% 40x40um2 cell

~ 55% 50x50um2 “

~ 72% 100x100um2 “


20098x8 array of SiPMs

1.5x1.5mm pitch

50x50mm2 cell

Device Layout: examples of SiPM geometries

2006

1x1mm2

40x40mm2 cell

2007

4x4mm2

50x50mm2 cell

Scale of the pictures is the same

Produced for DaSiPM (INFN project)


Process & Device characterization at FBK

Wafer level testing:-Automatic IVs: forward and reverse on all devices

-Failure analysis in case of problems

Wafer dicing

Packaging of some samples

Functional tests:- Dark analysis in climatic chamber

- Laser response

- Photo-detection efficiency

- Energy & timing resolution with scintillators

8

On-wafer automatic characterization

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1.E-03

0 5 10 15 20 25 30 35

I [A

]

Vrev [V]

Reverse charact.

- Functionality of the device

- Breakdown voltage

- Dark count estimate

4 elements of the array

0.0E+00

1.0E-03

2.0E-03

3.0E-03

4.0E-03

5.0E-03

6.0E-03

7.0E-03

8.0E-03

0 0.5 1 1.5

I [A

]

Vfor [V]

Forward charact.

- Functionality of the device

- Resistor value estimate

4 elements of the array

9

Example of faulty device

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

0 5 10 15 20 25 30 35 40

no defect

1 defective pixel (13V)

I22

I11

Most common defect is premature breakdown

Working SiPM.

The current can

be roughly modeled

as I=q*DC*G

SiPM with 1 defective cell.

I=(V-Vbd)/Rq

Vbd

light emission picture @16V

Reverse IV plot

10

… after packaging…

1.E-13

1.E-12

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0

Cu

rre

nt

(A)

Bias Voltage (V)

-40 -30

-20 -10

0 10

20 30

40

0.0E+00

2.0E-04

4.0E-04

6.0E-04

8.0E-04

1.0E-03

1.2E-03

1.4E-03

0.25 0.40 0.55 0.70 0.85 1.00 1.15

Cu

rre

nt

(A)

Bias Voltage (V)

-40-30-20-10010203040

Reverse IV plot

Forward IV plot

(quenching resistor value

is temperature dependent)

Temperature (C)

Temperature (C)

11

Dark analysis in climatic chamber

original data,

acquired with scope

Dark count rate

vs

threshold (blue)

single-cell signal

(blue),

mean signal

(red)

pulse area

histogram (blue),

baseline (red)

pulse distance

histogram

pulse amplitude

distribution

vs

distance

For each bias voltage, Labview program performs following:

under

construction

FBK/AdvanSiD, USA tour 2011C. Piemonte

Breakdown

&

Gain


0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

2.5E+06

3.0E+06

3.5E+06

4.0E+06

4.5E+06

5.0E+06

28 30 32 34 36 38 40

Gai

n

Bias (V)

-30C

+30CGain

Bias Voltage (V)

0%

1%

2%

3%

4%

5%

6%

7%

8%

9%

10%

0 1 2 3 4 5 6

Gai

n s

hif

t (1

/K)

Bias Voltage (V)

Ga

in s

hift (1

/K)

Bias Voltage (V)

y = 0.076x + 30.934

28

29

30

31

32

33

34

35

-40 -20 0 20 40

BV

(V)

Temperature (°C)

Bre

akd

ow

n v

olta

ge

(V

)

Temperature (C)

76mV/C


0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

2.5E+06

3.0E+06

3.5E+06

4.0E+06

0 1 2 3 4 5 6 7

Dar

k co

uts

(Hz)

Overvoltage (V)

.-30° C

.-20° C

.-10° C

0° C

10° C

20° C

30° C

0.0E+00

1.0E+05

2.0E+05

3.0E+05

4.0E+05

5.0E+05

-45 -35 -25 -15 -5 5 15 25 35 45

Qu

en

chin

g re

sist

ance

(Oh

m)

Temperature (°C)

Dark count

Quenching resistor


doubles every 10C

temperature increase

increasing with

decreasing temperature

Da

rk c

ou

nt ra

te (

HZ

/mm

2)

Over-Voltage (V)

Qu

en

ch

ing r

esis

tan

ce

(o

hm

)

Temperature (C)


Photo-detection efficiency

Using the Poisson rate

we get rid of after-pulse

and optical cross-talk

0%

5%

10%

15%

20%

25%

30%

350 400 450 500 550 600

PD

E

Wavelength (nm)

Vex=1.91

Vex=4

PDE =PoissonLight - PoissonDark

Number of incident photons

Measured with low level constant light


Application-oriented development:

HYPERIMAGE TOF-PET

16

w/o-

ToF

With

ToF

Example: TOF-PETTime-Of-Flight Positron Emission Tomography

Info from the SiPM: Energy and timing


Critical SiPM parameters for TOF-PET

Photo-detection efficiency

Dark noise rate

Correlated noise

Intrinsic timing capability

Signal shape

Geometry

Gain

SiPM parameters

Energy resolution

Timing resolution

System requirements

Other important SiPM features for such a large system are:

- temperature dependence

- breakdown voltage uniformity

- Voltage operability range- …

- packaging/interconnectivity


Framework of the development

Development of a hybrid TOF-PET/MR test

system with improved effective sensitivity

First clinical whole body PET/MR

investigations of breast cancer

HYPERimagehttp://www.hybrid-pet-mr.eu


HYPERimageToF-PET

PMT APD SiPM

MR compliant no yes yes

ToF compliant yes no yes

The Stack

The module

Pre-clinical

system

WB system

Why SiPMs?

https://wiki.ehv.campus.philips.com/twiki/pub/HYPERImage/WorkPackage1/Hypertile.png


Photosensor activity

Sensor tiles production to equip a machine

Development of improved SiPMs

Tuning of both technology as well as design

- geometry definition

- integration scheme definition

- device production

- signal shape

- cells density

- PDE

- Vbd uniformity

- Temperature dep.

some results presented @ IEEE NSS/MIC 2009

some results presented @ IEEE NSS/MIC 2010


SiPM production: geometry definition


Production

Lot production time: ~3-4 months

2x2 array of ~4x4mm2 SiPMs

3600 cells per element

Wafer view

Data analysis (1) - yield

white = OK

red = premature breakdown

green/blue = problems after breakdown

29.0 6.0 28.8 28.9 28.8 28.7 28.6 28.8 26.0 29.4

28.8 28.5 28.4 28.6 28.9 28.9 28.7 28.7 28.8 29.0

28.7 28.7 28.9 28.7 28.4 28.4 28.5 28.7 28.9 29.1 29.1 28.9 28.9 15.0

28.6 28.4 28.4 28.6 28.7 28.9 28.6 28.6 28.6 28.8 29.2 29.3 12.0 28.9

28.8 28.6 27.0 28.4 28.8 29.1 29.2 29.1 28.9 28.8 28.7 29.0 29.2 29.1

28.3 28.7 28.7 28.7 28.8 28.9 29.3 29.4 29.3 29.1 28.8 28.7 28.6 28.7

28.3 28.2 15.0 29.1 29.4 29.4 29.4 29.3 29.3 29.4 29.1 28.8 28.7 28.5

28.4 28.4 28.5 28.8 16.0 29.9 29.9 29.6 29.3 29.1 28.9 28.9 28.8 28.6

28.6 28.6 28.8 29.1 29.4 29.8 30.1 30.1 29.8 29.2 28.8 28.6 28.5 28.9

28.4 28.5 29.1 15.0 29.6 29.8 29.9 29.9 29.5 29.4 29.0 28.6 28.6 28.5

28.5 15.0 28.9 16.0 29.7 30.1 30.0 29.6 29.2 29.0 29.0 28.7 28.7 28.5

28.9 29.0 29.1 29.3 29.4 29.7 29.9 29.7 29.1 28.6 28.5 28.7 28.5 28.7

28.7 29.1 29.3 29.6 29.6 29.5 29.4 29.3 29.1 28.8 28.6 28.3 28.3 28.6

28.9 28.9 29.1 29.5 29.7 29.6 29.4 29.0 28.6 28.7 28.6 28.4 28.4 28.4

29.1 29.1 29.0 29.3 29.4 29.6 29.3 28.9 28.6 28.4 28.2 28.4 28.6 28.7

29.1 29.2 18.0 12.0 29.2 29.2 29.0 28.9 28.8 28.4 28.2 28.3 28.4 28.7

26.9 29.1 29.3 29.3 29.3 17.0 28.7 28.6 28.6 28.6 28.5 28.5 28.5 28.5

12.0 29.2 12.0 29.2 29.1 13.0 28.7 28.5 28.4 28.4 28.6 28.7 28.7 28.9


Solution for Scintillator coupling

epoxy (120mm)

Si

bonding pad

epoxy


The SiPM tile

32.7mm

32.7mm • Fill factor ~ 84%

(not including SiPM FF)

• Flat surface for crystal

mounting

1300 working arrays

delivered for the

preclinical system

PCB design and mounting

at Uni. Heidelberg and Philips

500mm


The stack

SiPM tile

ASIC tile

The module

Mechanics


Device optimization: Cell design

metal line every

second column

67x67um2 cell size, 3600 cells

Fill factor = 60%

metal every column

different Rq and Cq80x80um2 cell size, 2500 cells

Fill factor = 65%

metal every column

relatively high RQ

50x50um2 cell size, 6400 cells

Fill factor = 48%

metal every column

V0

V1 V2


Experimental characterization

Na22 radiation

sourceSiPM + LYSO

• SiPMs: 4x4mm2, produced @ FBK, n-on-p technology

• LYSO crystals: 3.8x3.8x22mm3, teflon-wrapped

slightly smaller section than SiPM for easier alignment

• voltage amplifiers: Rin=20ohm; G=2.5

voltage

amplifierThermostatic

chamber


4

5

6

7

8

9

10

11

12

13

2 3 4 5 6 7 8 9 10

En. R

es

(%)

Over-voltage (V)

SiPM 1

SiPM 2

CRT<325ps @ 4-6V

Best results:67x67v2

dE/E<11% @ 5-9V

compared to 14% of worse design

compared to 460ps of worse design


Device optimization: technology

We are working on several aspects:

- PDE improvement: increasing the triggering probability

- uniformity and stability of operating conditions

- new interconnection with TSV

We have interesting preliminary results on all aspects

which hopefully could be soon presented


SiPM

technology

20052010

SiPM R&D

AdvanSiD: genesis

FBK

SiPM

commercializationOptoI

Diatec

packaging

administration/

marketing


Standard products

Metal Can Package Chip Scale Package

1x1, 3x3, 4x4 mm2 SiPM size

More standard products will be soon available:- circular 1.2mm diameter- evaluation sipm tile: 4x4 elements of 4x4mm2 SiPMs


Custom products

Custom package design

Capability of reducing development costs by organizing multi-project runs

Modular complex sensors in plastic or alumina packages

Custom chip design


Acknowledgment

FBK SRS group:

Gabriele Giacomini

Alberto Gola

Elisabetta Mazzucca

Tiziana Pro

Alessandro Piazza

Nicola Serra

Alessandro Tarolli

Nicola Zorzi

HyperImage

DaSiPM & MEMS projects

AdvanSiD team!!

SiPM technology at FBK - Fermilabdetectors.fnal.gov/wp-content/uploads/2017/09/Piemont.pdfThe SiPM...

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