Variations of carrier recombination and trapping parameters due to - - PowerPoint PPT Presentation

SLIDE 1

Outline (as a new “cheap” Si we still wait from Lancaster U, we concentrate on details of

different Si different irradiated, also a series of samples are ready for calibration at CERN).

 Carrier recombination and trapping characteristics  Lifetime variations in different type Si under isothermal (80 C) anneals  Lifetime variations Si under isochronal (24) anneals in temperature range of 100-300 C  Recombination and trapping lifetime variations in Si irradiated with various particles  Deep centres in highly irradiated by neutrons Si  Summary

Variations of carrier recombination and trapping parameters due to anneals in Si irradiated with various particles

J.Vaitkus, E.Gaubas, T.Čeponis, A.Mekys, D.Meskauskaite,V.Rumbauskas, V.Vertelis

Vilnius University, Institute of Applied Research, Vilnius, Lithuania

M.Moll, C.Gallrapp, F.Ravotti

CERN

SLIDE 2

The device for integrated fluence monitoring

• The device for the contactless fluence

monitoring delivered to CERN, the instruction book given, the seminar for the staff members organized, Vilnius team member is ready to come if necessary.

• The calibration procedure has started, and

to proton and neutron irradiation the irradiation by pions was added.

SLIDE 3

Trapping and recombination lifetime variations dependent on trap concentration, level activation energy and excitation density

20 30 40 50 60 10

• 3

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• 2

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• 1

10

5 4 3 2 1 Er = 0.43 eV, Etr = 0 1 - Etr = 0.2 eV 2 - 0.3 3 - 0.35 4 - 0.4 5 - 0.5

I (a.u.) 1/kT (eV

• 1)

20 30 40 50 60 10

• 1

10 10

1

10

2

10

3

Etr = 0.3 eV 6 5 4 3 2 1 7

Mtr = 1*10 14 cm

• 3 -1

5*10 14 -2 1*10 15 -3 5*10 15 -4 1*10 16 -5 5*10 16 -6 be prilipimo -7

I (a.u.) 1/kT (eV

• 1)

20 30 40 50 60 10

• 3

10

• 2

10

• 1

10

5 4 3 2 1 Er = 0.43 eV, Etr = 0 1 - Etr = 0.2 eV 2 - 0.3 3 - 0.35 4 - 0.4 5 - 0.5

I (a.u.) 1/kT (eV

• 1)

20 30 40 50 60 10

• 1

10 10

1

10

2

10

3

Etr = 0.3 eV 6 5 4 3 2 1 7

Mtr = 1*10 14 cm

• 3 -1

5*10 14 -2 1*10 15 -3 5*10 15 -4 1*10 16 -5 5*10 16 -6 be prilipimo -7

I (a.u.) 1/kT (eV

• 1)

. a- Simulated trapping coefficient dependence on temperature for trapping level with activation energy of 0.23 eV in Si. b- Variations of recombination and instantaneous trapping lifetimes as a function of reciprocal thermal energy varying activation energy and concentration of trapping centres.

2 , , , , , , , , ,

) ( 1 ; n N N T K K

Ttr h e V C Ttr h e V C tr tr tr R tr inst

      

SLIDE 4

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• 1

10 10

1

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Okmetic MCZ<100> 1kOhm·cm 300 m MWR, CIS 8556- 14 wafers 1 - 63 passivated CIS 8556- 14 wafers measured by DG technique CIS 8556-01 diodes neutron irradiated

R (ns) Fluence (n/cm

2)

Recombination lifetime as a function of fluence in the as-irradiated Si materials

SLIDE 5

Recombination characteristics of the proton irradiated and isothermally (Tan =80 C) annealed Si

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12

10

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14

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15

10

16

10 10

1

10

2

10

3

Fluence (cm

• 2)

R (ns)

FZ-n As-irradiated Annealed: 80

• C 4 min.

80

• C 8 min.

80

• C 16 min.

80

• C 30 min.

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10 10

1

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3

Fluence (cm

• 2)

R (ns)

Cz-p As-irradiated Annealed: 80

• C 4 min.

80

• C 8 min.

80

• C 16 min.

80

• C 30 min.

26 GeV protons

SLIDE 6

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• 2

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• 1

10 10

1

10

2

 (cm

• 2)

R, eff (s)

as-irradiated Cz Si corrected for s Cz Si Annealed at T=80 C texp=4 min Cz Si texp=4 min corrected for s Cz Si texp=4+8 min corrected for s Cz Si texp=4+8+16 min corrected for s Cz Si texp=4+8+16+32min corrected for s Cz Si texp=2h+4min corrected for s Cz Si texp=4h+12min corrected for s Cz Si texp=8h+28min corrected for s Cz Si

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• 2

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• 1

10 10

1

10

2

R, eff (s)  (cm

• 2)

as-irradiated Fz Si corrected for s Fz Si Annealed at T=80 C texp=4 min corrected for s Fz Si texp=4+8 min corrected for s Fz Si texp=4+8+16 min corrected for s Fz Si texp=4+8+16+32min corrected for s Fz Si texp=2h+4min corrected for s Fz Si texp=4h+12min corrected for s Fz Si texp=8h+28min corrected for s Fz Si

Recombination lifetime in Cz and FZ Si samples as a function of pion fluence

SLIDE 7

Comparison of characteristics of the pion, neutron and proton irradiated and isothermally (Tan =80 C) annealed Si

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• 4

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• 2

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• 1

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2

FZ n-Si (native oxide) 300 MeV pions as -irradiated 80 C annealed 510 min. 26 GeV protons (non-corr.s) as -irradiated 80 C annealed 70 min. reactor neutrons MCz n-Si surfaces passivated with therm.SiO as -irradiated 80 C annealed 1440 min.

R (s)

1 MeV n eqv. (cm

• 2)

SLIDE 8

Trap spectra in 6.6 MeV electron irradiated Si samples as a function of fluence evaluated by O- I-DLTS

The Arrhenius plots obtained for different separated spectral peaks are illustrated in figure (c) for sample irradiated with fluence of Φ=1×1016 e/cm2.

60 90 120 150 180 210

• 0.04
• 0.02

0.00

• 3
• 2
• 1

T (K)

IO2 VO V

= 2

EA-V

(b) (a) O-I-DLTS signal (arb. units.)

n-Cz =10

16 cm

• 2

2´10

16 e/cm 2

3´10

16 e/cm 2

4´10

16 e/cm 2

5´10

16 e/cm 2

V

• 2+VP

V

= 3

50 100 150 200 52 54 56 58 60 (c)

ln(em´vth´NC) 1/kT (eV

• 1)

V

• 2+VP

V2

=

V

= 3

VO EA-V IO2

SLIDE 9

DLTS spectra dependent on annealing temperature recorded on Schottky diodes irradiated with fluence of Φ=1016 e/cm2. b- The Arrhenius plots obtained for different spectral peaks obtained in diodes annealed at 280°C.

DLTS spectra in electron irradiated Si samples after isochronal (24 h) anneals

50 100 150 200 250 1 2 3 4 5 VP V2O V

= 2

V3O VO V

• 3

V

• 2

n-Cz

=10

16 e/cm 2

as irradiated Annealed Tan= 80

• C

180

• C

280

• C

C-DLTS signal (arb. units.) T (K)

50 100 150 200 250 300 50 52 54 56 58 60

ln(em´vth´NC) 1/kT (eV

• 1)

V2O V3O V

= 2

VO V

• 3

(b)

SLIDE 10

a- The MW-PC transients recorded on the diode sample irradiated with fluence 4×1016 e/cm2 using different scan temperatures T. b-Variations of the carrier recombination (τR) and trapping (τtr) lifetimes as a function of the reciprocal thermal energy (kT) for sample irradiated with fluence 4×1016 e/cm2 after heat treatment at Ta= 280°C.

MW-PC characteristics in electron irradiated Si samples after isochronal (24 h) anneal at Tan =280 C varying scan temperature T for transients 50 100 150 10

• 3

10

• 2

10

• 1

10 4 3 2

MW-PC signal (arb. units.) t (s)

1

n-Cz, =4´10

16 e/cm 2, Tan=280

• C

1 T=110 K 2 130 K 3 250 K 4 290 K

(a)

40 60 80 100 10 10

1

10

2

R, tr (s)

1/kT (eV

• 1)

=4´10

16 cm

• 2

Tan=280

• C

R tr

(b)

280240 200 160 120

T (K)

SLIDE 11

Comparison of the simulated (curves) and experimental (symbols) variations of the carrier trapping lifetimes τtr as a function of reciprocal thermal energy for samples irradiated with fluence 4´1016 e/cm2 and annealed for 24 h at temperatures T

an=1800C (a) and Tan=2800C (b).

Here, the bold curve represents a sum of emission flows from different trapping levels those form the single thermal emission peaks, shown by thin solid curves. Simulations of the resultant τtr(T) spectrum were performed including temperature dependent changes of the recombination lifetime τR(T).

Trapping spectra measured by MW-PC in 6.6 MeV electron irradiated Si samples after isochronal (24 h) anneal at Tan =280 C varying scan temperature T of transients

SLIDE 12

Defect Heat- treatmen t Non-annealed Annealed at 80°C at 180°C at 280°C Φ=1016 e/cm2 Method 1 5 1 5 1 5 1 5 Concentration of trapping centres (1014 cm-3) V2

/

VP DLTS 0.83 2.2 1.2 2.1 0.7 0.21

• V2O

DLTS 0.083

• 0.12
• 0.08

3

• 0.21

0.23 MW-PC

• 3.4
• 5

V3O DLTS 0.035

• 0.18
• 0.15
• 0.17

0.065 MW-PC

• 0.97

1.8

• V3

=

DLTS

• >10

>100 >100

• >100
• MW-PC
• 6

15

• 9

4 3 V2

=

DLTS 11 6.4 14 8.5

• 8.1

1.9

• MW-PC
• 1.4
• 1.2

0.2 0.5

• VO

DLTS 3.1 5.6 4.8 7.9 2.7 5 1.4

• IO2

DLTS

• 0.072

0.95 0.19 2.7 0.14 V3



DLTS

• 0.84

2.2 0.96 0.1 0.96 0.1 A-V DLTS

• >100
• >100
• Parameters
• f

the carrier emission centres dependent

• n

heat-treatment temperature extracted by O-I-DLTS and MW-PC techniques

SLIDE 13

Trapping spectra measured by MW-PC in pion irradiated Si samples after isochronal (24 h) anneal at Tan =150 C varying scan temperature T of transients

Comparison of the simulated (curves) and experimental (symbols) variations of the carrier trapping lifetimes τtr as a function of reciprocal thermal energy for n-Fz Si (a) and n-Cz Si (b) samples irradiated with fluence 1´1014 e/cm2 and annealed for 24 h at temperatures Tan=1500C

40 50 60 70 80 90 0.0 0.5 1.0 1.5 VO V2

=

n-Fz, =1×10

14 /cm 2, Tan=150

• C

Experiment Simulations R tr,i single trap tr tr (traps)

R, tr (s) 1/kT (eV

• 1)

CiOi

(a)

50 60 70 80 90 100 200 VO CiOi V2

=

n-Cz, =1´10

14 /cm 2, Tan=150

• C

Experiment Simulations R tr,i single trap tr tr (traps)

R, tr (s) 1/kT (eV

• 1)

(b)

SLIDE 14

Trapping spectra measured by MW-PC in proton irradiated n-Fz and p-Cz Si samples after isochronal (24 h) anneal at Tan =250 C varying scan temperature T of transients

40 50 60 70 80 90 0.1 1 10

=1´10

14 p/cm 2, Tan= 250 C 24h

p-Cz n-Fz R R tr tr

R, tr (s) 1/kT (eV

• 1)

(a)

40 50 60 70 80 0.00 0.01 0.02 0.03 0.04 0.05 V2

• V2

=

n-Fz, =5´10

15 p/cm 2, Tan= 250 C 24h

Experiment Simulations R tr,i single trap tr tr (traps)

R, tr (s) 1/kT (eV

• 1)

VO

(b)

a-Variations of the carrier recombination (τR) and trapping (τtr) lifetimes as a function of the reciprocal thermal energy (kT) for p-Cz and n-Fz samples irradiated with fluence 1×1014 e/cm2 after heat treatment at Tan= 250°C. b- Comparison of the simulated (curves) and experimental (symbols) variations of the carrier trapping lifetimes τtr as a function of reciprocal thermal energy for n-Fz Si sample irradiated with fluence 5´1015 e/cm2 and annealed for 24 h at temperatures Tan=2500C

SLIDE 15

Deep level spectroscopy

• The high neutron fluence introduce deep donors that increased the

dark conductivity

• The main deep centers are at 0,5 and 0,8 eV (optical activation energy)

0,6 0,8 1,0 1,2 1,4 1E-15 1E-14 1E-13 1E-12 1E-11 1E-10 1E-9 1E-8 1E-7 I, A

E, eV

I, if h increases I-I0 decrease h

Fisherbrand 260868-1-41 1E16 m7 U = -50V T=30 K

0,4 0,6 0,8 1,0 1,2 1,4 1E-12 1E-11 1E-10 1E-9

I, A h, eV decrease increase I-I0decrease I-I0increase MCZ Si microstrip (43 m) 1e17 cm-2 neutrons 10 V, 21 K

SLIDE 16

Recombination prevails in the as-irradiated material, and recombination lifetimes fit a single curve in lifetime-fluence dependence for neutrons, protons and pions as well as for various technology Si materials Isothermal (80C) anneals (hadron irradiated Si) lead to enhance

• f trapping effect, - 2-componential decay transients

with long asymptotic decay Amplitude and instantaneous lifetime of trapping component depends on irradiation fluence Trapping indicates increase of the role of point defects. Spectra of trapping lifetime correlate with those of O-I-DLTS, while variation

• f peaks ascribed to different point traps vary with temperature

(100 -300 C) of isochronal (24 h) anneals, indicating non-trivial transforms of radiation defects.

Summary

SLIDE 17

Acknowledgements: Lithuanian Academy of

Science partially supported these investigations under grants 2016-CERN-VU-EG (lifetime and trapping results) AND CERN-VU-2016-1 (deep level spectra) (Thanks to G.Kramberger for the microstrip samples and AIDA2020 TNA for the samples irradiation at TRIGA reactor) This research was performed in framework of AIDA-2020 grant

CERN

Thank you

for your attention!