Ioana Pintilie, Vilnius 2-6 june 2007 1

Defect investigation on MCz after 1 MeV neutron irradiation

I. Pintilie1, E. Fretwurst2, A. Junkes2 and G. Lindstroem2

1 National Institute of Materials Physics, Bucharest, P.O. Box MG-7, 077125, Romania

2Institute for Experimental Physics, Hamburg University, D-22761, Germany

Ioana Pintilie, Vilnius 2-6 june 2007 2

Materials

MCz-Silicon wafers: <100>, n/P, 100 μm, 1090 cm, Nd = 3.96x1012 cm-3, CiS process (samples 8556-02-25, 8556-05-35 and 8556-05-19)

EPI-Silicon wafers: <111>, n/P, 72 μm on 300 μm Cz-substrate, 169 cm, Nd = 2.55x1013 cm-3, CiS process

-standard Oxidation (EPI-ST) (samples 8364-02-35 and 8364-01-33)

- diffusion oxygenated for 24 h/1100°C (EPI-DO) (samples 8364-05-36 and 8364-06-27)

Irradiation: - 1MeV neutrons at Ljubljana; fluences of 3x1011cm-2 and 5x1013 cm-2

- 26 MeV protons (for comparison with 1 MeV neutrons)

Annealing : Isothermal treatments at 80 0C

Investigation methods: - I-V, C-V, TSC, C- DLTS

Ioana Pintilie, Vilnius 2-6 june 2007 3

Defects in unirradiated samples

TDD-s already present in the as-grown material

H = 0.115 eV Ea = 0.15 eV

an = 2.26x10-15 cm2

n = 2.7x10-12 cm2

NT = 5.14x1010 cm-3

E(112K) – unkown defect present in the as-grown material:

H = 0.224 eVa

n = 3x10-15 cm2

NT = 2.89x1010 cm-3

25 50 75 100 125 150 175 200 225 250-0.01

0.00

0.01

0.02

0.03

0.04

0.05

DLT

S s

igna

l b1

[pF

]

E(112K)

TDD+/++

T[K]

MCz - unirradiated, electron traps

Ioana Pintilie, Vilnius 2-6 june 2007 4

TSC results

0 25 50 75 100 125 150 175 2000

2

4

6

8

10

12

14

16

18

20

H(116K)

BD+/++ CiOi

H(40K)

E(28K)

V2+?

BD0/++

VO

TS

C s

ignal (

pA

)

Temperature (K)

5x1013 n/cm2, as irradiated EPI- ST

EPI-DO (BD0/++) EPI-DO (BD+/++) MCz - normalized to Epi thickness

20 40 60 80 100 120 140 160 180 2000

2

4

6

8

10

12

14

[BD] = 8x1011 cm-3

EPI-DO, 5x1013 cm-2 (1MeV neutrons)

(0/++)(+/++)

BD

TS

C s

igna

l (pA

)

Temperature (K)

as irradiated 3 h at 295K

Bistability of BD

Ioana Pintilie, Vilnius 2-6 june 2007 5

Ci, BD and IO2 defects

42 44 46 48 50 52 54 56 58 600

1

2

3

4

IO2

Ci

BD+/++

TS

C s

igna

l (pA

)

Temperature (K)

5x1013 n/cm2

EPI-ST as irradiated

EPI-DO 3H at RT (BD0/++)

EPI-DO as irradiated (BD+/++) MCz as irradiated

46 48 50 52 54 56 581

2

3

4

5

6

7

8

9

10

IO2

TS

C s

igna

l (pA

)

Temperature (K)

MCz - 5x1013 n/cm2

F-500V F-300V F-100V F 50V

44 46 48 50 52 54 56 580.0

0.5

1.0

1.5

2.0

2.5

3.0EPI-ST

Ci

-/0

TS

C s

ignal (

pA

)

Temperature (K)

100 V 70 V 50 V 20 V

44 46 48 50 52 54 56 580.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0EPI-DO

BD+/++

TS

C s

igna

l (pA

)

Temperature (K)

150 V 100 V 70 V 50 V 20 V 10 V

Ioana Pintilie, Vilnius 2-6 june 2007 6

BD = TDD2

84 87 90 93 96 99 102 105

0.0

0.5

1.0

1.5

2.0

2.5

3.0EPI-DO, 3 h at room temperature

BD0/++

TS

C s

ign

al (

pA

)

Temperature (K)

F-300V F-250V F-200V F-150V F-100V F-70V F-50V F-20V F-10 V

BD(+/++): H = 0.145 eV

an = 6.8x10-12 cm2

NT as irradiated = 4.8x1011 cm-3

BD(+/++): H = 0.23 eV

an = 1.2x10-15 cm2

NT 3h at RT = 3.8x1011 cm-3

20 30 40 50 60 70 80

0

2

4

6

8

10EPI-DO, as irradiated

BD+/++

TS

C s

igna

l (pA

)

Temperature (K)

F - 100V F - 70 V F - 50 V F - 20 V F - 10 V

VO

H(42K)

E(25K)

E(45K)

Ioana Pintilie, Vilnius 2-6 june 2007 7

Annealing studies at 80 0C

0 25 50 75 100 125 150 175 200 225

0

10

20

30

40

50

60

70MCz - =5x1013 cm-2

BD+/++

IO2

VO

V2+?

CiOi

H(116K)

BD0/++

E(30K)

E(28K)

H(42K)

TS

C s

igna

l (pA

)

Temperature (K)

Annealing time at 80 0C 0 min. 20 min. 80 min. 160 min. 320 min. 640 min. 1370 min. 2810 min. 5700 min. 11460 min. 16980 min.

0 25 50 75 100 125 150 175 200

0

5

10

15

20

BD+/++

45K

EPI-DO

H(42K)

H(116K)BD0/++

V2+?

CiOi

VO

E(30K)

E(25K)

TS

C s

igna

l (pA

)Temperature (K)

F-150V F - 150V - 20min@80C F - 150V - 80min@80C F - 150V - 160min@80C F - 150V - 320min@80C F - 150 V - 640min@80C F - 150V - 1370min@80C F - 150V - 2810min@80C F - 150V - 5700min@80C F - 11460min@80C F - 16980min@80C

Ioana Pintilie, Vilnius 2-6 june 2007 8

E45K level ~ TDD+/++

38 40 42 44 46 48 50

0.5

1.0

1.5

E45K ~ TDD+/++

TS

C s

igna

l (pA

)

Temperature (K)

F - 250 V - 1370 min@80 C F - 150V - 1370min@80C F - 70V - 1370min@80C

Ea = 0.135 eV

n = 6x10-12 cm2

Ioana Pintilie, Vilnius 2-6 june 2007 9

Defects Concentration

1 10 100 1000 10000 1000001010

1011

1012

1013

Annealing time at 800C (min)

Def

ect c

once

ntra

tion

(cm

-3)

E25K E30K H42K BD+/++ E(45K) VO BD0/++ H(116K) CiOi VV+? IO2

MCz

1 10 100 1000 10000 1000001010

1011

1012

1013

Annealing time at 800C (min)

Def

ect c

once

ntra

tion

(cm

-3)

E25K E30K H42K BD+/++ E(45K) VO BD0/++ H(116K) CiOi VV+?

EPI-DO

  E25K E30K H42K BD+/++ E45K VO BD0/++ H116K CiOi VV+? IO2

Ea  0.06  0.06  0.09  0.145  0.135  0.17  0.23  0.28 0.36  0.41-0.47

 0.11

 10-14  7x10-16  7x10-15  6x10-12  6x10-12 14x10-15 1x10-15  2x10-15 17x10-16  1x10-15  7x10-16

Ioana Pintilie, Vilnius 2-6 june 2007 10

1 10 100 1000 100000.0

2.0x1012

4.0x1012

6.0x1012

8.0x1012

1.0x1013

VV+? CiOi VO

Def

ect c

once

ntra

tion

(cm

-3)

Annealing time at 800C (min)

EPI-DO

1 10 100 1000 10000

0.0

2.0x1011

4.0x1011

6.0x1011

8.0x1011

1.0x1012

De

fect

co

nce

ntr

atio

n (

cm-3)

EPI-DO E25K H(116K) BD0/++ E(45K) BD+/++ H42K

Annealing time at 800C (min)

- 30% increase of [VO] during annealing V released from clusters may cause formation of complexes with deep acceptor levels (V2O, V2O2)- 20% increase of the donors concentration during the first 20 min

0.1 1 10 100 1000 100002x1011

3x1011

4x1011

5x1011

6x1011

7x1011

8x1011

9x1011

[BD

+E

45K

] (c

m-3)

Annealing time at 80C (minutes)

EPI-DO EPI-ST MCz

Ioana Pintilie, Vilnius 2-6 june 2007 11

DLTS results on MCz

80 160 240

0.0

0.1

0.2

0.3

0.4

0.5

V2

-/0+?

V2

=

TDD+/++

VO

8556-02-25: MCz, 3E11 n/ cm2, annealing at 80°C and 200°C (Tw=200ms).

b 1 coe

ffici

ent [

pF]

T [K]

as irr 4 min at 80°C 30 min at 80°C 1440 min at 80°C 30 min at 200°C

90 180

-0.3

0.0

CiOi+/0

8556-02-25: MCz, 3E11 n/ cm2, annealing at 80°C and 200°C (Tw=200ms)

b 1 co

rrel

ator

[pF

]T [K]

as irr 4 min at 80°C 30 min at 80°C 1440 min at 80°C 30 min at 200°C

Electron trapsmeasured during cooling

Hole trapsmeasured during heatingPulsing with forward bias

Ioana Pintilie, Vilnius 2-6 june 2007 12

DLTS-annealing results

1 10 100 10000.00E+000

5.00E+010

1.00E+011

1.50E+011

2.00E+011

2.50E+011

3.00E+011Annealing results at 80 (full) and 200 oC (open symbol)

Con

cent

ratio

n [c

m-3]

Annealing time [min]

VO V2=/- V2-/0 VO 30 min at 200C V2=/- 30 min at 200C V2-/0 30 min at 200C

Ioana Pintilie, Vilnius 2-6 june 2007 13

Comparison between TSC results after 1MeV neutron and 26 MeV proton irradiation

- E30K, H42K, IO2, VO – enhanced generation after 26 MeV protons

- H42K and IO2 defects – strongly generated in MCz

0 25 50 75 100 125 150 175 2000

10

20

30

40

50

60

70

80

90

100

V2+?

BD+? H(116K)

CiOi

VO

IO2

E(30K)

H(42K)

MCz - 80min@80C

TS

C s

igna

l (pA

)

Temperature (K)

1 MeV neutron irradiation 26 MeV protons

0 25 50 75 100 125 150 175 2000

10

20

30

40

50

60

70

80

H(42K)

VO

V2+?

CiOi

H(116K)

BD

E(30K)

EPI-DO, 80min80C

TS

C s

igna

l (pA

)

Temperature (K)

1 MeV neutrons 26 MeV protons

Ioana Pintilie, Vilnius 2-6 june 2007 14

Summary

MCz, EPI-ST and EPI-DO were studied comparatively after irradiation with 1 MeV neutrons and 26 MeV protons

Main radiation induced defects:• IO2 – only in MCz• H(42K) – strongly formed in MCz, impurity related

• Ci - only in EPI-ST

• BD&TDD - the lowest generation in MCz?! - increase in the concentration during the first 20min at 80 C

• VO - the highest introduction rate in EPI-diodes (double compared with MCz)- 30% increase of [VO] during annealing V released from clusters

may cause formation of complexes having deep acceptor levels (V2O, V2O2)

• H(116K), CiOi and V2 & clusters – same generation rate in all materials