Leonid I. Murin Leonid I. Murin 1,21,2 and and Bengt G. Svensson Bengt G. Svensson 22

11 Joint Institute of Solid State and Semiconductor Joint Institute of Solid State and Semiconductor

Physics, Minsk, BelarusPhysics, Minsk, Belarus2 2 Oslo University, Centre for Materials Science and Oslo University, Centre for Materials Science and

Nanotechnology, Oslo, NorwayNanotechnology, Oslo, Norway

INTERACTION OF INTRINSIC DEFECTS WITH OXYGEN IN NEUTRON-IRRADIATED MCZ-SI:

AN INFRARED ABSORPTION STUDY

OUTLINE

• Experimental• IR spectra of n-irradiated MCz-Si samples• Annealing at 80 C• Annealing at 150-250 C• I2 and I2O defects: what we know • Conclusions

Experimental

• Samples: MCz-Si crystals ( [Oi] = 5x1017 cm-3, [Cs] < 5x1015 cm-3)Dimensions were 10 × 6 × 2.8 mm

• Treatments:Room temperature neutron (1x1015, 3x1015, 1x1016, 3x1016 cm-2) irradiation Thermal anneals in the range 80-250 ºC

• Measurements: FTIR (Bruker IFS 113v) at 12-30 K (resolution 0.5 cm-1) and/or 300 K (resolution 1.0 cm-1) in the wavenumber range 400-4000 cm-1.

700 800 900 1000 1100

0.0

0.5

1.0

1.5

3x1016

1x1016

3x1015

1x1015

OiTmeas = 300 K

MCzSi6 n-irradiated at RT

I2OiVO

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

750 800 850 900 950 1000 1050

0.00

0.05

0.10

0.15

0.20

0.25

933

830

Tmeas = 300 K

O2i1013

MCzSi6 n-irradiated at RT

3E15

1E15

1E16

1008

I3Oi?

I2Oi

CiOi

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

800 900 1000 1100

0.00

0.05

0.10

0.15

0.20

0.25

Oi

933830

Tmeas = 300 K

O2i

1013

Difference: 3x1016 - 1x1015 cm-2

1008I3Oi?

I2Oi

CiOi

VO

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

0 5 10 15 20 25 30

0.00

0.05

0.10

0.15

[VO] = 6.5x1015 cm-3

Dose dependence

Tmeas = 300 K

I3O?CiOi

I2O

VO

830 cm-1

933 cm-1

862 cm-1

1006 cm-1

A

bsor

ptio

n co

effic

ient

, cm

-1

Fluence, 1015 cm-2

750 800 850 900 950 1000 1050 1100

0.0

0.1

0.2

0.3

0.4

IO2i

18Oi

835.8

935.7

Tmeas = 25 K

O2i

1012.4

MCzSi6 n-irradiated at RT

3E15

1E15

1E16

1011I3Oi?

I2Oi

CiOi

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

800 900 1000 2700 2800 2900 3000

0.0

0.1

0.2

0.3

0.4

0.5

x0.5

2767

V2 excitation

18Oi

835.8

935.7

Tmeas = 25 K

O2i

LVMs of O-related defects and V2 electronic transitions

3E15

1E15

1E16

1011I3Oi?

I2Oi

CiOi

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

800 900 1000 2700 2800 2900 3000

0.0

0.1

0.2

0.3

0.4

0.5

x0.5

2767

V2 excitation

18Oi

835.8

935.7

Tmeas = 25 K

O2i

LVMs of O-related defects and V2 electronic transitions

3E15

1E15

1E16

1011I3Oi?

I2Oi

CiOi

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

750 800 850 900 950 1000 1050

0.00

0.05

0.10

0.15

0.20

0.25Isothermal annealing at 80 C

Tmeas = 300 K

MCz6-10 irradiated with 3x1016 cm-2 neutrons

80C 60 min

80C 3 h

80C 30 min

80C 5 min

I3Oi?

I2Oi

CiOi

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

800 900 1000 1100

0.00

0.05

0.10

0.15

0.20

0.25

Oi

80C 30 min - before anneal

Isothermal annealing at 80 C, difference spectra

Tmeas = 300 K

MCz6-10 irradiated with 3x1016 cm-2 neutrons

80C 6 h - before anneal

I2Oi

VO

DA

C, c

m-1

Wavenumber, cm-1

800 900 1000 2700 2800 2900 3000

0.0

0.1

0.2

0.3

0.4

0.5

Difference: 80C 12 h - before anneal

Isothermal annealing at 80 C, difference spectra

x0.5

2767

V2 excitation

835.8

935.7

Tmeas = 25 K

I2Oi

VO

DA

C, c

m-1

Wavenumber, cm-1

0 200 400 600 800 1000 1200

0.1

145 C

60 C

80 C

MCz6-10, 3E16, 80C, = 25 min MCz6-8, 1E16, 80C, = 26 min MCz6-7, 1E16, 60C, = 277 min MCz6-11, 1E16, 45C, = 1672 min linear fits

N = N0exp(-t/)

U

nann

eale

d fra

ctio

n 9

36(t)

/93

6(0

)

Annealing time, min

2.8 2.9 3.0 3.1 3.2

103

104

105

(preliminary results)

Estimation: T = 295 K, = 30 days

Temperature dependence of I2O life-time

= -1exp(E/kT)

E = 1.16 ± 0.1 eV

= 2.5*1013 s-1

, s

1000/T, K

750 800 850 900 950 1000 1050

0.0

0.1

0.2

0.3

0.4

250C 30 min

Annealing 80-250 C

Tmeas = 300 K

MCz6-10 irradiated with 3x1016 cm-2 neutrons

200C 30 min

80C 24 h

150C 30 min

I3,4Oi?

I2Oi

CiOi

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

800 900 1000 1100

0.00

0.05

0.10

0.15

0.20

0.25

V3O

Oi

Difference spectrum, 250C 30min - 150C 30min

Tmeas = 300 K

MCz6-10 irradiated with 3x1016 cm-2 neutrons

V2O

DA

C, c

m-1

Wavenumber, cm-1

750 800 850 900 950 1000 1050 1100

0.0

0.2

0.4

0.6

0.8MCz6-10 irradiated with 3x1016 cm-2 neutrons

Annealing 80-250 C

1062

250C 30min

200C 30min

18Oi

835.8 935.7Tmeas = 25 K

150C 30min

80C 24 h

1011I3,4Oi?

I2Oi

CiOi

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

820 830 840 850

0.0

0.2

0.4

0.6

0.8

V3O-

V3O0

V2O-

V2O0

MCz6-10 irradiated with 3x1016 cm-2 neutronsAnnealing 80-250 C

250C 30min

200C 30min

835.8Tmeas = 25 K

150C 30min

80C 24 h

VO

3E16

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

800 900 1000 2700 2800 2900 3000

0.0

0.2

0.4

0.6

0.8

250C 30min

200C 30min

150C 30min

80C 24h

3E16

MCz6-10 irradiated with 3x1016 cm-2 neutronsAnnealing 80-250 C

x0.25

2767V2

18Oi

Tmeas = 25 K

I3,4Oi?

I2Oi

CiOi

VO

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

800 820 840 860 2700 2800

0.0

0.1

0.2

0.3

0.4

Difference spectrum, 250C 30min - 200C 30min

842.4

833.4

V3O

3E16

MCz6-10 irradiated with 3x1016 cm-2 neutrons

x0.25

2767

V2

Tmeas = 25 K

V2O

Abs

orpt

ion

coef

ficie

nt, c

m-1

Wavenumber, cm-1

I2, I2O - WHAT IS KNOWN

I2 defect

I2O defect

Some latest publications

Davies G., Hayama S., Murin L., Krause-Rehberg R., Bondarenko V., Sengupta A., Davia C., and Karpenko A. Radiation damage in silicon exposed to high-energy protons // Phys. Rev. B. – 2006. - Vol. 73, N 16. – P.165202 (1-10). Hermansson J., Murin L.I., Hallberg T., Markevich V.P., Lindstrom J.L., Kleverman M., and Svensson B.G. Complexes of the self-interstitial with oxygen in irradiated silicon: a new assignment of the 936 cm-1 band // Physica B: Condensed Matter. - 2001. - Vols. 302-303. - P. 188-192.

Some conclusions• - The dominant infrared absorption bands observed in neutron-

irradiated bulk MCzSi are the bands related to VO and I2O (vibrational modes) and V2 (electronic transitions). The CiOi-related LVMs are already saturated after a dose of about 1x1015 cm-2. Some traces of ICiOi, IO2i and I2O2i could be detected as well.

• -After irradiation with doses (1-3)x1016 cm-2 a new band at 1011 cm-1 is appearing, which could be related to I3O or I4O defects. The 1011 cm-1 band anneals out at 200 C.

• -Annealing at 80C results in elimination of I2O (monitored by an absorption band at 936 cm-1) and in growth of VO (absorption band at 836 cm-1). Annealing of I2O obeys the 1-st order kinetics with an activation energy of about 1.1-1.2 eV and pre-factor 2.5x1013 s-1 .

• - Annealing at 250C results in elimination of V2 (monitored by an absorption band at 2767 cm-1) and in growth of V2O (band at 833.4 cm-1) and V3O (band at 842.4 cm-1) defects.