DLTS measurements of Epitaxial and MCZ silicon detectors after 26 MeV proton irradiation

F. Hönniger(a), A. Furgeri(b), E. Fretwurst(a), G. Lindström(a), I. Pintilie(c), (a) Institute for Experimental Physics, University of Hamburg (b) Institut fuer Experimentelle Kernphysik,University of Karlsruhe (c) National Institute for Materials Physics, Bucharest

2

OutlineOutline

Motivation Material properties Experimental methods Measurements and results Conclusions

3

Shallow Donors, the real issue for EPIShallow Donors, the real issue for EPI-Comparison of 25, 50 and 75 -Comparison of 25, 50 and 75 µm Diodes-µm Diodes-

0 10 20 30 40 50 60 70 80 90 100Depth [m]

51016

51017

51018

5

O-c

once

ntra

tion

[1/c

m3 ]

SIMS 25 m SIMS 25 m

25 m

u25

mu

SIMS 50 mSIMS 50 m50

mu

50 m

uSIMS 75 mSIMS 75 m

75 m

u75

mu

simulation 25 msimulation 25 msimulation 50 msimulation 50 msimulation 75msimulation 75m

0 2.1015 4.1015 6.1015 8.1015 1016

eq [cm-2]

0

1014

2.1014

Nef

f(t0)

[cm

-3]

25 m, 80 oC25 m, 80 oC50 m, 80 oC50 m, 80 oC75 m, 80 oC75 m, 80 oC

23 GeV protons23 GeV protons

SIMS profiling: [O](25µm) > [O](50µm) > [O](75µm)

Stable Damage:Neff(25µm) > Neff(50µm) > Neff(75µm)

TSC Defect Spectroscopy:[BD](25µm) > [BD](50µm) >[BD](75µm)

Defect spectroscopy after PS p-irradiation

Generation of shallow donors BD (Ec-0.23 eV) strongly related to [O] Possibly caused by O-dimers, dimers monitored by IO2 complex

Strong correlation between [O]-[BD]-gC

generation of O (dimer?)-related BD reason forsuperior radiation tolerance of EPI Si detectors

80 100 120 140 160 1800.0

0.2

0.4

0.6

0.8

1.0

1.2

Nor

mal

ised

TS

C s

igna

l (pA

/m

)

Temperature (K)

75 m 50 m 25 m

BD0/++

CiO

i

V2

-/0+?

80 100 120 140 160 1800.0

0.2

0.4

Nor

mal

ised

TS

C s

igna

l (pA

/m

)

Temperature (K)

75 m 50 m 25 m

BD0/++

CiO

i

V2-/0+?

≈ 105 V (25 µm)

≈ 230 V (50 µm)

≈ 320V (75 µm)

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MaterialMaterial

Epi/Cz: n-type, 145 Ωcm, 75 μm on 300 μm Cz-substrate, Cis process

(with and without DO)MCZ: n-type, 880 Ωcm, 300 μm , Cis process

0 20 40 60 80 100

depth [m]

1016

1017

1018

O-c

onc.

[1/c

m3 ]

4487, epi process only4487, epi process only8364-01, full process without DO8364-01, full process without DO8364-06, full process with DO8364-06, full process with DO

6.8e176.8e17

SIMS O-profiles, 75 m n-epi

4487, 8364-01, 8364-06 | 29.5.2006

0 20 40 60 80 100

depth [m]

1017

1018

O-c

onc.

[1/c

m3 ]

8556-06, FOX only8556-06, FOX only8556-08, FOX+4h/975+1h/8508556-08, FOX+4h/975+1h/850

5.8e175.8e17

8556-01, full process8556-01, full process

SIMS O-profiles, 300 m n-MCz

8556, 300 MU N-MCZ | 29.5.2006

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Experimental MethodsExperimental MethodsIrradiation source: 26 MeV protons Defect characterisation

by C-DLTFS Measurement of depth

profile taking transition region into account.

RD

P

RR

P

R

RDt C

CN

CC

AC

CC

CCNN 0

1

0

2

0 21212

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DLTS SpectraDLTS Spectra

EPI DO: Φeq= 8.2 x 1011 cm-2 p+ 26 MeV UR= -20V, UP=-0.1V TW= 200ms, TP= 100ms

0 50 100 150 200 250 300

0,0

0,1

0,2

0,3

0,4

0,5

0,6

ER(40K)

IO2

VO

V2(=/-)ER(174K)

V2(-/0)

b 1[pF]

T[K]

EPI DO 75m

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DLTS SpectraDLTS Spectra

EPI standard: Φeq= 8.0 x 1011 cm-2 p+ 26 MeV UR= -20V, UP=-0.1V TW= 200ms, TP= 100ms

0 50 100 150 200 250 300

0,0

0,1

0,2

0,3

0,4

0,5

0,6

ER(34K)

ER(40K)

Ci

VO

V(=/-)

ER(174K)

V(-/0)

b 1[pF]

T[K]

EPI 75m standard

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DLTS SpectraDLTS Spectra

EPI standard (backside): Φeq= 8.0 x 1011 cm-2 p+ 26 MeV UR= -80V, UP=-60V TW= 200ms, TP= 100ms

0 50 100 150 200 250 300

0,0

0,1

0,2

0,3

0,4

0,5

0,6

ER(34K)

ER(40K)

Ci

VO

V(=/-)

ER(174K)

V(-/0)

b 1[pF]

T[K]

EPI 75m standard

0 50 100 150 200 250 300

0,0

0,1

ER(40K)IO2

VO

V2(=/-)ER(174K)

V2(-/0)

b 1[pF]

T[K]

EPI standard 75m

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DLTS SpectraDLTS Spectra

MCZ: Φeq= 4.6 x 1011 cm-2 p+ 26 MeV UR= -20V, UP=-5V TW= 200ms, TP= 100ms

0 50 100 150 200 250 300

0,0

0,2

0,4

0,6

0,8

1,0

[TDD]=4,3x1010cm-3

ER(40K)ER(174K)

IO2

VO

V2(=/-)

V2(-/0)

b 1[pF]

T [K]

MCz

MCz before irradiation (Up=-0,1V)

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Depth profil IODepth profil IO22

0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0

2,0x1011

4,0x1011

6,0x1011

8,0x1011

[IO2]

[cm

-3]

d/d0

75 m DO-EPI eq

=4,8 x 1011cm-2 (26 MeV p+) 75 m EPI

eq=4,8 x 1011cm-2 (26 MeV p+) ([IO

2] x 3)

MCz eq

=4,6x1011cm-2(26 MeV p+)

In DO-EPI and MCZ [IO2] is almost homogeneous like [O]

In EPI standard [IO2] is strongly inhomo-geneous like [O]

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Bistability of IOBistability of IO22

-1 0 1 2 3 4 5 6

1

2

3

[IO2][

1011

cm-3]

UP [V]

75 m DO-EPI eq=4,8x1011cm-2(26 MeV p+)50 60 70 80 90 100

0,00

0,05

0,10

0,15

0,20

0,25

IO2

VOi

IO2b 1[p

F]

T[K]

75 m DO-EPI eq

=4,8x1011cm-2(26 MeV p+)T

W=200ms, T

P=100ms U

R=-20V, U

P=-0,1V

no Forward Bias after 3V Forward Bias

Change of state by forward biasing

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Introduction ratesIntroduction rates

0,0

0,4

0,8

1,2

1,6

2,0

2,4

2,8

0,0

0,4

0,8

1,2

1,6

2,0

2,4

2,8

Intro

duct

ion

rate

[1/c

m]

EPI DO EPI standard MCZ

V2(=/-) V

2(-/0)VO

i

VO:

Similar introduction rate like for 23 GeV p+ irradiation

MCZ is higher after 26 MeV p+ irradiation.

V2(=/-):

Similar introduction rate like for 23 GeV p+ irradiation

V2(-/0):

Introduction rate is only half of what was found after 23 GeV p+ irradiation

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New Epi materials show high [O] and high [IO2] like in MCZ

Depth caracteristics of [IO2] corresponds with [O] IO2 defect shows bistability Introduction rates of vacancy related defects are

nearly the same for investigated materials

ConclusionsConclusions