WP15.5 - Si for large fluence irradiation monitoring Variations of - - PowerPoint PPT Presentation

SLIDE 1

Our purpose in AIDA-2020 is to find a most convenient Si for the irradiation fluence monitoring and imaging: to find a cost effective solution, therefore we analyze, the high resistivity, electronic grade, solar energy grade, multicrystalline samples, and we still wait a special “cheap Si” wafers of Si from Lancaster U, and in general we concentrate on details of different Si differently irradiated.

The series of samples are ready for calibration at CERN).

Variations of carrier recombination and trapping parameters 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

WP15.5 - Si for large fluence irradiation monitoring

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

Fluence imaging (our proposal for LHC(b) - our vision):

• 1. Two Si wafer pieces (Fig.)

put around the proton beam. 2. Irradiate. 3. Remove. 4. Scan the lifetime distribution across both pieces. 5. Transform the lifetime map to the integrated fluence image. The fluence range 1e12- more that 1e16 hadrons/cm2.

(If the irradiation will be more than 3e16 cm-2, then this area will be necessary to scan by

• ther method, purely optical)

SLIDE 4

Si

Needle-tip coaxial MW antenna

d~300 m Single mode fiber

This device for 2D integrated fluence imaging up to 3“.

Cross-sectional scans within wafer depth

Laisvakrūvės zondavimo būdai

I(t) MW IR L,  MW, IR  = arctg eff

sample

excite probe

sample

probe/ excite

sample

U (t)f

pulsed laser beam cw MW or IR cw laser beam

Ipr (t)f

excite / probe

I(t)

Laisvakrūvės zondavimo būdai

I(t) MW IR L,  MW, IR  = arctg eff

sample

excite probe

sample

probe/ excite

sample

U (t)f

pulsed laser beam cw MW or IR cw laser beam

Ipr (t)f

excite / probe

I(t) I(t) MW IR L,  MW, IR  = arctg eff

sample

excite probe

sample

probe/ excite

sample

U (t)f

pulsed laser beam cw MW or IR cw laser beam

Ipr (t)f

excite / probe

I(t)

It can scan sample in different regimes: transmission, reflectance and probe

SLIDE 5

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

10

11

10

12

10

13

10

14

10

15

10

16

10

• 4

10

• 3

10

• 2

10

• 1

10 10

1

10

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 6

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 7

Recombination and trapping

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)

SLIDE 8

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

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)

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 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

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 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

Different Si crystals were investigated and their possibilities for the hadron fluence monitoring and for the hadron beam imaging were determined. 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 of 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 of 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 15

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!

SLIDE 16

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 17

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