trd2005,bari,10.09.05

TRD2005,Bari,10.09.05

Progress report on SiPM development and its applications

Boris DolgosheinMoscow Engineering and Physics Institute

Boris@mail.cern.ch

Single photon Avalance Diodes(SPAD’s): S.Cova et al.,Appl.Opt.35(1996)1956

Silicon Photomultiplier (SiPM)

NEXT STEP: Large area SiPM`s from 1x1 mm2 > up to 10x10 mm2

R 50

h

substrate

50

Ubias

Multipixel (typically ≤ 1 mm2) Geiger mode photodiode with common readout

TWO STEPS IN DEVELOPMENTS OF GEIGER MODE APD: FIRST STEP: SINGLE PHOTON AVALANCHE DIODE (SPAD),

based on single pixel “photon counter” SECOND STEP: from SPAD to

Depletion1-2m

46 pixels fired

B.Dolgoshein,’Large area SiPM’s…’

SiPM’s have been developed in Russia during last ~10 years(see International Conferences on New Developments in Photodetection ICNDP-1999,2002,2005)

There are four SiPM’s producers for the time being-at the level of test batches production:

Center of Perspective Technology and ApparatusCPTA,Moscow

MEPhI/Pulsar Enterprise,Moscow

JINR(Dubna)/Micron Enterprise

HAMAMATSU started the SiPM production last year

R 50

h

pixel

Ubias

Al

Depletion Region2 m

Substrate

20m

42m

Pixel size ~20-30m

Working point: VBias = Vbreakdown + V ~ 50-60 V V ~ 3V above breakdown voltage

Each pixel behaves as a Geiger counter withQpixel = V Cpixel with Cpixel~50fmF

Qpixel~150fmC=106e

Electrical inter-pixel cross-talk minimized by: - decoupling quenching resistor for each pixel - boundaries between pixels to decouple them reduction of sensitive area and geometrical (packing) efficiency

Very fast Geiger discharge development < 500 ps

Pixel recovery time = (Cpixel Rpixel) ~ 20 ns …1mks

Dynamic range ~ number of pixels saturation

ResistorRn=400 k -20M

SiPM today-reminder:

Sensitive area : 3x3 mm2 # of pixels: 5625

Depletion region: appr. 1 m Pixel size: 30 mx30 m Working voltage: 20…25 V Gain: 1…2

x10**6 Dark rate.room temperature: 20 MHz SiPM noise(FWHM):

room temperature 5-8 electrons -50 C 0.4 electrons

Single pixel recovery time: 1us After pulsing probability: appr. 1%

Optical crosstalk: appr. 30 - 50 % ENF: appr. 1.5-2.0(overvoltage dependent)

3x3mm SiPM parameters

300 400 500 600 700 8000

20

40

60

80

100

QE·geom

SiPM 3x3 (T=-50 0C)

PMT XP2020Q number 40979(according Philips Photonics)

APD EG&G C30626E (NIM A428 (1999) 413-431)

QE

, %

Wavelength , nm

SiPM 1x1 (T=+20 0C)

Spectral dependence of the photon detection efficiency (PDE) for different photodetectors

178nm-5.5%,(1mmx1mm SiPM)

0

10

20

30

40

0 1 2 3 4 5 6

0

5

10

15

20

Ubreakdown

=48V

one pixel gain (exp. data)

One

pix

el g

ain

M, 1

05

Overvoltage U=U-Ubreakdown

, V

detection efficiency ( =565nm)

Eff

icie

ncyo

f lig

ht re

gistr

atio

n, %

one pixel gain (linear fit)

Photon detection efficiency= QE(~80%)xx packing efficiency(active/total area,~40%)xx Geiger efficiency(~70%)

Optical Crosstalk OC

–due to secondary light emitted in Geiger discharge: 10**-5 photons/one electron

adjacent pixels are fired- fig’s.

OC increases drastically with a Gain

becomes >1 for a Gain > few timesx10**7 selfsustening discharge pixel independence and Poisson statistics of fired pixels are violated Excess Noise Factor ENF becomes too large

Secondary light: Effective absorption length(Si)- appr. 50 mkm Effective wavelength- appr. 1000 nm

B.Dolgoshein,’Large area SiPM’s…’

0 1 2 3 4 5

1E-3

0,01

0,1

1

96 mkm

128 mkm

64 mkm

Op

tica

l cro

ssta

lk

Gain, 106

32 mkm

B.Dolgoshein,’Large area SiPM’s…’

200 400 600 800 1000

1

10

100

1000

10000

1

0

Co

un

ts

QDC channel

SiPM Z-type. U-Ubd

=8V. kopt

=1,85. tgate

=80ns.

QDC LeCroy 2249A. Noise.

B.Dolgoshein,’Large area SiPM’s…’

Optical crosstalk,SiPM 1x1 mm2,dark noise

Crosstalk==>non-Poissonian distribution:

pixel fired/phe=1.7 ENF=1.6

Crosstalk suppression by special SiPM topology:test structure,PRELIMINARY!

Poisson distribution:

pixel fired/phe= 0.98+-0.03 ENF= 0.97+-0.05

Gain 3x10**6

Gain 3x10**7

0 100 200 300 400 500 6001

10

100

1000

10000

eve

nts

channel

0 2000 4000 6000 8000 10000 120000

200

400

600

800

1000

1200

1400

1600

1800

2000

Data: Data1_ampModel: ExpDecay1 Equation: y = y0 + A1*exp(-(x-x0)/t1) Weighting:y No weighting Chi^2/DoF = 565.44691R^2 = 0.99897 y0 1932.69131 ±11.98254x0 77.60337 ±--A1 -1926.00611 ±--t1 1615.08307 ±37.05734

Am

plit

ud

e o

f th

e s

eco

nd

im

pu

lse

, m

V

Distance between two light impulses, ns

Recovery time. SiPM Z105 (U=60,13). Ubreakdown

=52,4V. 13/01/2005

LED L53SYC (595nm), timpulse

=10ns, Ugen

=-9v, L=1sm.

Chargefirst and second impulse arear = (-2,6:10) ns = -10,60622 V*nsone pixel arear = (-0,4:4)ns = -0,01907 V*nsN

pixels = 556

Recovery time of single pixel: C(pix)xR(pix)-->20ns…..a few mks

5

6

7

8

9

10

11

12

8 10 12 14 16 18 20 22 24 26200

250

300

350

400

450

500

550

MIP

MIP

, QD

C c

hann

els

Temperature T, 0C

a) pixel gain

Pixe

l gai

n, 1

05

0

5

10

15

20

53 54 55 56 570

250

500

750

1000

MIP

MIP

, QD

C c

hann

els

Bias voltage U, V

b) pixel gain

Pix

el g

ain,

105

Fig.5

Temperature and bias voltage dependence:delta T(V) Gain Signal=GainxPDE -1 C +2.2% +4.5% +0.1V +4.3% +7%

LED signal ~150 pixels

A=f(G, , x)

Comparison of the SiPM characteristics in magnetic field of B=0Tand B=4T

(very prelimenary, DESY March 2004)

No Magnetic Field dependence at 1% level

(Experimental data accuracy)

SiPM signal saturation due to the limited total number of Sipm’s pixels

1 10 100 1000 100001

10

100

1000

Number of pixels fired

Number of photoelectrons

576 1024 4096

Response functions for the SiPMs with different total pixel numbers measured for 40 ps laser pulses

Long term stability of SiPM

20 SiPMs worked during 1500 hours

Parameters under control:

•One pixel gain

•Efficiency of light registration

•Cross-talk

•Dark rate

•Dark current

•Saturation curve

•Breakdown voltageNo changes within experimental errors

5 SiPM were tested 24 hours at increased temperatures of 30, 40, 50, 60, 70, 80, and 90 degrees

No changes within experimental accuracy

SiPM long term stability

0 2 4 6 8 10 12 14 16 18 2010-2

10-1

100

101

102

103

before tests after 500 hours after 1500 hours

dark rate, kHzSi

PM p

aram

eter

s

SiPM number

efficiency of light registration, %

gain (*106)

dark current, microAmper

Parameters under control:

•Efficiency of light registration

•One pixel gain

•Dark rate

•Dark current

20 tested SiPMs worked during 1500 hours

SiPM today:+ -

Low noise,high gainGood single electron resolutionVery good timingSmall recovery timeVery low nuclear counting effectInsensitivity to BSimple calibration and monitoringVow bias voltageLow power consumptionCompactnessRoom temperature operationGood T and V stabilitySimplest electronicsRelatively low expected cost(lowresistivity Si,simple technology)

Not very high PDE

Small area

High dark rate(~ area)

Exess Noise Factor islarge enough due to Optical Xtalk