Theory of the Ion Beam Induced Charge Technique...

2359-9

Joint ICTP-IAEA Workshop on Physics of Radiation Effect and its Simulation for Non-Metallic Condensed Matter

Ettore Vittone

13 - 24 August 2012

University of Turin Italy

Theory of the Ion Beam Induced Charge Technique (IBIC)

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1

ETTORE VITTONE

Dipartimento di Fisica, Università di Torino

www.dfs.unito.it/solid

Theory of the Ion Beam Induced Charge Technique (IBIC).

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Bibliography

Books:M.B.H. Breese, D.N. Jamieson, P.J.C. King, “Materials Analysis Using a Nuclear Microprobe”, John Wiley and Sons, 1996

Articles:M. B. H. Breese, E. Vittone, G. Vizkelethy, P.J. Sellin, “A review of ion beam induced charge microscopy”, Nuclear Instruments and Methods in Physics Research B 264 (2007) 345–360.See slides

Links:http://www.dfs.unito.it/solid/RICERCA/IBA/IBA_index.html

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Theory of the Ion Beam Induced Charge Technique (IBIC).

From nuclear spectroscopy to material analysis Principles of IBIC From spectroscopy to microspectroscopy Basic equations Validation of the theory Charge sharing

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IBIC for thefunctional characterization of

semiconductor materials and devices

Measurement of the their electronic properties and performances

Main physical observable: currentCurrent = F(carrier density; carrier transport)

Free carriers (electron/hole) transportTwo mechanisms: Drift electric field v=μ·EDiffusion concentration gradient

Carrier generation by MeV ionsGeneration profileRecombination/trappingCarrier lifetime

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PrinciplesPrinciples ofof radiationradiation detection detection techniquestechniquesDeposited Energy

Free charge generation and transport

Output Electrical Signal Vout

Transport)Carrier Free Energy, Deposited(FVout

Nuclear spectroscopy

Incoming radiation

V

Q

Incoming radiation

V

Vout

Well known

Measured

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IBIC principlesIBIC principles


Incoming radiation

V

Q

Incoming radiation

V

Vout

MeasuredWell known Material Characterization

Deposited Energy

Free charge generation and transport

Output Electrical Signal Vout

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Incoming radiation

V

Q

Incoming radiation

V

Vout

MeasuredWell known

MeV ion energy deposition

Electron/hole pair generation

Charge carrier transport

Induced Charge at the sensing electrode

Output Signal Vout

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Electrode energy loss very small ( 1%)SRIM (Stopping and Range of Ion in Matter)

Using MeV ions to probe

the electronic features of semiconductors

analysis through thick surface layerscharge pulses height spectra almost independent on topography .profiling

long range

low lateral scattering

a wide choice of ion ranges and electronic energy losses

0 5 10 15 20 25 300

1x107

2x107

3x1070

50

100

150

200

3 keV Photon current: 5*107 photons/sXBIC

X-ra

y en

ergy

loss

rate

(keV

\(m

s-1)

Depth (m)

IBICH+ ion energy (MeV)

1.71.51.31.10.90.7

Stop

ping

pow

er

(keV

m-1)

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Incoming radiation

V

Q

Incoming radiation

V

Vout






Output Signal Vout

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Electron/Hole pair generation eh

ioneh

EN

A. Lo Giudice et al. Applied Physics Letters 87, 22210 (2005)

1 MeV ion in diamond generates about 77000 e/h pairsEach high energy ion creates large numbers of charge carriers to be measured above the noise level.

εeh=average energy expended by the primary ion to produce one electron/hole pair

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Incoming radiation

V

Q

Incoming radiation

V

Vout






Output Signal Vout

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J.R. Haynes, W. Shockley,

“The mobility and life of injecting holes and electrons in germanium,

Phys. Rev. 81, (1951), 835-843.

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C. Canali et al., Nucl. Instr. Meth. 160 (1979) 73-77

400 m thick natural diamond, biased at 40 V @ RT

P-doped Ge;resistivity about 15 Ω·cm; dielectric constant =1.4pF/cm; Dielectric relaxation time = 21 ps.Charge neutrality maintained

IIa diamond; resistivity about 1015 Ω·cm; dielectric constant =0.5 pF/cm; Dielectric relaxation time = 500 s.Charge neutrality not maintained

J.R. Haynes, W. Shockley, Phys. Rev. 81, (1951), 835-843.

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Incoming radiation

V

Q

Incoming radiation

V

Vout

MeasuredWell known





Output Signal Vout

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Physical Observable:Induced current/charge

Vbias

Vout

q

dxqQ

Q0+Q

d

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Vbias

Vout

Physical Observable:Induced current/charge

W. Shockley, J. Appl. Phys. 9 (1938) 635.

S. Ramo, Proc. I.R.E. 27 (1939) 584.

dvq)t(I

T

0

dt)t(I)t(Q

q

d)t(xq)t(Q

Q0+Q(t)

d

v

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dvq)t(I

T

0

dt)t(I)t(Q

Constant velocity v

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-2 0 2 4 6 8 10 12 14

0.000

0.025

0.050

0.075

0.0

0.2

0.4

0.6

0.8

1.0

I

Time

Q

dvq)t(I

-2 0 2 4 6 8 10 12 14 16

0.000

0.025

0.050

0.075

0.0

0.2

0.4

0.6

0.8

1.0

I

Time

Q

texpdvq)t(I

drift time

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C. Canali et al., Nucl. Instr. Meth. 160 (1979) 73-77

400 m thick natural diamond,

biased at 40 V @ RT

IIa diamond; resistivity about 1015 Ω·cm; dielectric constant =0.5 pF/cm; Dielectric relaxation time = 500 s.

Charge neutrality not maintained

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V

Vout

d

v

Ed

dECCE

e

e

exp1 K. Hecht, Z. Physik 77, (1932) 23

Generation at the anode Induced signal from the

Hole motion

Generation at the cathode Induced signal from the

electron motion

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C. Canali, E. Gatti, S.F. Koslov, P.F. Manfredi, C. Manfredotti, F. Nava, A.

QuiriniNucl. Instr. Meth. 160 (1979) 73-77

400 m thick natural diamond,

biased at 40 V @ RT

Electrons:

Drift velocity; v dTR

Mobility; d2/(TR *VBias)

Characterization of the transport properties in diamond

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dvq)t(I

Shockley-Ramo Theorem

Induced current

Ev The current is induced by the motion of charges in

presence of an electric field

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Si-face

Starting Material: 360 m n-type 4H-SiC by CREE (USA)Epitaxial layer from Institute of Crystal Growth (IKZ), Berlin, GermanyDevices from Alenia Marconi System

4H-SiC Schottky diode

1.5 MeV H+

CC

E

2 MeV H+

0 20 40 60 80 1001201400,00,20,40,60,81,0

Applied Bias Voltage (V)

1.5 or 2.0

MeV H+

CCE=Charge Collection Efficiency=

(Charge collected)/(Charge generated)

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50 m thick N-type epitaxial 4H-SiC layerSchottky electrode

Frontal ion Irradiation

Dep

letio

n R

egio

n

FAST DRIFT

COMPLETE COLLECTION DIFFUSION

0 5 10 15 20 25 30 350

20

40

60

80

100

120

140

160

180

0

20

40

60

80

100

120

140En

ergy

Los

s (k

eV/

m-1)

Depth (m)

2 MeV1.5 MeV

Bragg.opj

Applied B

ias Voltage (V)

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Generation of electrons and holes in the

Depletion Region Neutral RegionD

eple

tion

regi

on

Electric Field

Neu

tral

re

gion

Electrons

Holes

Dep

letio

n re

gion

Neu

tral

re

gion

Electrons

Holes

Complete charge collection Only holes injected in the depletion region by diffusion induce a charge

Electric Field

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0 5 10 15 20 25 30 350

20

40

60

80

100

120

140

160

180

0

20

40

60

80

100

120

140

Ener

gy L

oss

(keV

/m

-1)

Depth (m)

2 MeV1.5 MeV

Bragg.opj

Applied B

ias Voltage (V)


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0 5 10 15 20 25 30 350

20

40

60

80

100

120

140

160

180

0

20

40

60

80

100

120

140

Ener

gy L

oss

(keV

/m

-1)

Depth (m)

2 MeV1.5 MeV

Bragg.opj

Applied B

ias Voltage (V)


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0 5 10 15 20 25 30 350

20

40

60

80

100

120

140

160

180

0

20

40

60

80

100

120

140

Ener

gy L

oss

(keV

/m

-1)

Depth (m)

2 MeV1.5 MeV

Bragg.opj

Applied B

ias Voltage (V)


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0 5 10 15 20 25 30 350

20

40

60

80

100

120

140

160

180

0

20

40

60

80

100

120

140

Ener

gy L

oss

(keV

/m

-1)

Depth (m)

2 MeV1.5 MeV

Bragg.opj

Applied B

ias Voltage (V)


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Lp=(9.0±0.3) m

Dp = 3 cm2/s

p = 270 ns

minority carrier

diffusion length

1.5 MeV

CC

E

2 MeV

0 20 40 60 80 1001201400,00,20,40,60,81,0

Applied Bias Voltage (V)


Active region width

4

5

6

7

8

9

10

100 150 200 250 300 350 4000,0100,0150,0200,0250,0300,0350,0400,0450,050 (b)

(a)

L p (

m )

L-2 p(

m-2 )

T (K)

Temperature dependent IBIC (TIBIC)

TTDTL ppp

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4

5

6

7

8

9

10

100 150 200 250 300 350 4000,0100,0150,0200,0250,0300,0350,0400,0450,050 (b)

(a)

L p (

m )

L-2 p(

m-2 )

T (K)

Two trapping levels

SRH recombination model

2 0.50.5p p p B Bt

D B

1 1 1 1 1 1 1 1AL D D (T) T EBT T exp

N k T

The fitting procedure provides a trapping level of about

0.163 eV which is close to the value found in similar

4H SiC Schottky diodes by DLTS technique (S1 level).

E. Vittone et al., NIM-B 231 (2005) 491.

Temperature dependent IBIC (TIBIC)

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Time resolved IBIC (TRIBIC)Silicon Power diode Mesa Rectifier

V

Charge sensitive preamplifier

ADC

Proton beam (2-3-4 MeV)

n p+ W

C

n+

IBIC

Digital oscilloscope TRIBIC

Shaping amplifier

Mesa Rectifier 168

Ballistic deficit

p+

n

n+

Electrodes (Ag-Ni-Cr)

30 m 160 m 110 m

Passivation “Mesa Glass”

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Time resolved IBIC (TRIBIC)Silicon Power diode Mesa Rectifier

lifetime

0 = (5 1) s

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From Spectroscopy to micro-spectroscopy

Use of focused ion beams

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20 m

20 m

Electrons10 keV

Electrons40 keV

2 MeV H+ in Si 3 MeV H+ in Si

4 MeV H+ in Si

2 m

4 m

6 m

47 m 90 m 147 mTrajectories

One advantage of IBIC over other forms of charge collection microscopy is that it provides high spatial resolution analysis in thick layers since the focused MeV ion beam tends to stay ‘focused’ through many micrometers of material.

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M.B.H.Breese et al. NIM-B 181 (2001), 219-224; P.Sellin et al. NIM-B 260 (2007), 293-294Intra-crystallite charge transport

Single grain IBIC line scan

Position (nm)0 50 100 150 200 250

Cou

nts

0

1000

2000

3000

4000

5000 200 V370 V

IBIC imaging with 2 MeV H+

Under

illumination

Dark

conditions

Polycrystalline

CVD diamond

Frontal IBIC

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GaAs Schottky diodeFrontal IBIC

0 5 10 15 20 25 300

500

1000

1500

2000 FRB L12, frontale30 V

Pixe

l

Efficiency (%)

0 20 40 60 80 100 1200

20

40

60

80

100

120

X Axis

Y A

xis

19.34 -- 20.84 17.84 -- 19.34 16.34 -- 17.84 14.84 -- 16.34 13.34 -- 14.84 11.84 -- 13.34 10.34 -- 11.84 8.840 -- 10.34 7.340 -- 8.840 5.840 -- 7.340

2 mm

1 cm

2 mm

1 cm

pre-amplifierSchottky contact

ohmic contact

(frontal irradiation)2 MeV protonmicrobeam

0.1

mm GaAs

sample holder

active region

Effects of inhomogeneous cabon dopingPoor spectral

resolution

E. Vittone et al., Nuclear instruments and Methods in Physics Research B 158 (1999) 470-47

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Schottky electrode 50 m thick N-type epitaxial 4H-SiC layer

0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 5 00

2 0

4 0

6 0

8 0

1 0 0

1 2 0

1 4 0

1 6 0

1 8 0

1 .71 .51 .31 .10 .9

Ene

rgy

Loss

(keV

/m

-1)

D e p t h ( m )

0 .7 Neutral region

Diffusion transport

Incomplete collection

Depletion region

Fast drift transport

Complete collection

0 , 2 0 0 00 , 2 5 0 00 , 3 0 0 00 , 3 5 0 00 , 4 0 0 00 , 4 5 0 00 , 5 0 0 00 , 5 5 0 00 , 6 0 0 00 , 6 5 0 00 , 7 0 0 00 , 7 5 0 00 , 8 0 0 00 , 8 5 0 00 , 9 0 0 00 , 9 5 0 01 , 0 0 0

0 1CCE

1 mm

M. Jaksic et al.Nuclear Instruments and Methods in PhysicsResearch B 188(1-4) (2002) 130-134

Surface defects

Bulkdefects

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ANGLE RESOLVED IBIC (ARIBIC)2 MeV proton beam

L=(9.9±0.8) m

Dead layer energy loss of 235 keV at =0°.

A. Lo Giudice et al. Nuclear Instruments and Methods in PhysicsResearch B 249 (2006) 213–216

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ElectrodeElectrode

Microbeam Microbeam raster area raster area for lateral for lateral IBICIBIC

5 MeV proton

Anode

Cathode

xy

z

xy

z

y

z

p+

n+Polished and passivated lateral

surface

Leakage current below 100 nA @ 100 V

Lateral IBIC

Si p-n diodeIon Microbeam Facility of Ruder Boskovich Institute, Zagreb (HR)

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p+ n

pLxexpxη

DepletionRegion

3 MeV proton

xy

z

xy

z

y

zLateral IBIC

Si p-n diode

minority carrier diffusion length

ppp DL

C. Manfredotti et al., Nuclear instruments and Methods in PhysicsResearch B 158 (1999) 476-480

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50 100 150 200 250

0,2

0,4

0,6

0,8

11

Lp = ( 61.4 ± 0.8 ) m = (2.90 ± 0.08)s

71.3 V

58.7 V

41.7 V

20.3 V

icnmta98.si_DIODE.articolsidiode.fig4

Col

lect

ion

effic

ienc

y

Depth (m)50 100 150 200 250

0,080,10,1

0,2

0,4

0,6

0,811

Lp = ( 27.3 ± 0.8 ) m = (0.57 ± 0.03)s 117.5 V

90.6 V

60.4 V28 V

icnmta98.si_DIODE.articolsidiode.fig5

Col

lect

ion

effic

ienc

yDepth (m)

Pristine diode Au doped diode

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Gunn’s theorem

Pulse shapes calculation

V-qI

Ev

Shockley-Ramo theorem

d1-qI v

Weighting field

Gunn theorem

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dtdrv Equation of motion:

Weighting potential:

VV www

E

AB

B

A

B

A

B

A

VVq)()(q

dEqdtEqIdtQ

AwBw

w

t

tw

t

t

rr

r

r

rr

rv

The induced charge Q into the sensing electrode

w-qV

-qI EvEv

is given by the difference in the weighting potentials between any two positions (rA and rB) of the moving charge

Weighting field

Induced current into the sensing electrode

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47Depth Depth W

eigh

ting

Wei

ghtin

gpo

tent

ial

pote

ntia

l 11

00

Wei

ghtin

gW

eigh

ting

field

field

Ele

ctric

E

lect

ric

Fiel

dFi

eld

Vw

EE

Vw

Depth Depth

Depth Depth

NeutralNeutralnn--typetype

Schottky Schottky barrierbarrier

DepletionDepletionRegionRegion

VVbiasbias

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Wei

ghtin

gW

eigh

ting

pote

ntia

lpo

tent

ial

11

00

Vw

Electric fieldElectric field

h+

e-

positioninitial

positionfinal VV

qQ

Electrons/holes

Electrostatics

Transport properties

Induced charge

Depth Depth

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Wei

ghtin

gW

eigh

ting

pote

ntia

lpo

tent

ial

Vw

11

00

h+

Depth Depth xx00

e-


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50

Wei

ghtin

gW

eigh

ting

pote

ntia

lpo

tent

ial

Vw

11

00

h+ e-


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Wei

ghtin

gW

eigh

ting

pote

ntia

lpo

tent

ial

Vw

11

00 Depth Depth xx00

e-

wx

electrons ofNumber Totalq

VVq

QQCCE

electronspositioninitial

positionfinal

Generated

collected 01


h+

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Wei

ghtin

gW

eigh

ting

pote

ntia

lpo

tent

ial

Vw

11

00 Depth Depth xx00


h+

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Wei

ghtin

gW

eigh

ting

pote

ntia

lpo

tent

ial

Vw

11

00

h+


wx

holes ofNumber Totalq

VVq

QQCCE

holespositioninitial

positionfinal

Generated

collected 0

11 00

wx

wx

holesholes

electronselectronsCCE

Generated

collected

Generated

collectedToT

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To evaluate the total induced charge

Magnetic effects are negligible;

Electric field propagates instantaneously

Free carrier velocities much smaller than the light speed

Excess charge does not significantly perturb the electric field

equation sPoisson’ thesolvingby potential actual theEvaluate

equations y)(continuitrt transpo theSolve

electrode sensitive at the potential bias theis VV

potentialweightingsGunn' theEvaluate

AB rr VV

qQThe induced charge Q into the sensing electrode is given by the difference in the weighting potentials between any two positions (rA and rB) of the moving charge

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Basic assumptionsMagnetic effects are negligible;

Electric field propagates instantaneously

n,p

UGJtp

UGJtn

ppp

nnn

Free carrier velocitiesmuch smaller than the lightspeed

Excess charge does notsignificantly perturb thefield within the detector

)n,p(

UGJtp

UGJtn

ppp

nnn

)n,p(

pGJtp

nGJtn

ppp

nnn

Linearization of ULinearization of U

QuasiQuasi--steadysteady--state modestate mode

ELECTROSTATICSELECTROSTATICS

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Basic formalism

p

pp0p

nnn0n

0

pGpDptp

nGnDntn

charge space ,conditions boundary by defined potential the

using equations continuity the Solve

dt)t,dQ(r)t,I(r

current induced the Evaluate

Sd)t,(r)t,Q(rcharge induced the Evaluate

00

00

)n,p( equation sPoisson’ the solving by

potential actual the Evaluate

0tat point Generation r)t()rr(G

0

0pn,

Rectifying contact

Ohmic contact

Semiconductor bulk

Insulator-Semiconductorinterface

Boundary conditionsBoundary conditions

Initial conditionsInitial conditions

For mapping charge pulsesFor mapping charge pulses

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Vip0n0

t

0i V

)r(E)r(v)r;'t,r(p)r(v)r;'t,r(nrd'dtq)t(Q

charge induced the Evaluate

constant held are conductors other the all of potentials The

E equation sPoisson’ the solving by

VE

potential weightedsGunn' the Evaluate

i

p

pp0p

nnn0n

0

pGpDptp

nGnDntn

charge space ,conditions boundary by defined potential

the using equations continuity the Solve

Rectifying contact

Ohmic contact

Semiconductor bulk

Insulator-Semiconductorinterface

Bou

ndar

y B

ound

ary

cond

ition

sco

nditi

ons

Initial conditionsInitial conditions

For mapping charge pulsesFor mapping charge pulses

0tat point Generation r)t()rr(G

0

0pn,

Formalism based on the Gunn’s theorem

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equation continuity electron the for function sGreen' the isV

)r(E)r(v)r;'t,r(nrd'dtq)t(Q

electrons from Induced Charge

Vin0

t

0in

The continuity equation involves linear operators

The charge induced from electrons can be evaluated by solving a single, time dependent adjoint equation.

n

n*

n0nnGnDn

tn

inn

in

VEG

Qn

T.H.Prettyman, Nucl. Instr. and Meth. in Phys. Res. A 422 (1999) 232-237.

Short-cutAdjoint equation Method

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Monte Carlo MethodShockley-Ramo-Gunn TheoryA charge moving in a non-zero electric field induces a current to the sensitive electrode.∂ψ/∂V is the Gunn’s weighting potential, where ψ is the electric potential and V the bias voltage

Short-cut

Follow the carrier trajectories by a Monte Carlo approachTaking into accountphysical parameters (geometry, electric field, transport properties)experimental set-up (noise, threshold, beam spot size)

P. Olivero et al., Nucl. Instr. Meth. B 269 (2011) 2350

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Diamond Schottky diode structure: homoepitaxial growth on HPHT

substrates (type Ib, 440.4 mm3) slightly B

doped (Acceptor concentration 1013-1014 cm-3)

heavily B-doped buffer layer asback contact (Acceptorconcentration 1018-1019 cm-3)

25 μm thick intrinsic layer asactive volume

Schottky contact: frontal Al circularcontact ( = 2 mm, 200 nm thick) onintrinsic layer

back contact on B-doped layer ohmiccontact

sample cleaved in order to expose itscross section for IBIC characterization

S. Almaviva et al. “Synthetic single crystal diamond dosimeters for conformal radiation therapyapplication”, Diamond & Related Materials 19 (2010) 217–220

ideality factor: n = (1.51 0.04)series resistance: Rs = (5.1 1.6) kΩ

back B-doped contactshunt resistance: Rsh = (900 6) GΩ@ 50 V -> I<50 pA

Lateral IBIC of a diamond Schottky diode

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ion species and energy: H+ @ 2 MeV ion current: 103 ions s-1 no pile up

or charging effects ion beam spot on the sample:

FWHM = 3 μm raster-scanned area: S = 6262 μm2

charge sensitive electronic chain and synchronous signal

acquistition with microbeam scanning

Lateral IBIC measurements performed at the ion microbeam line of the AN2000 accelerator of the

National Laboratories of Legnaro (LNL-INFN)

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Plateaux:Depletion region(active region)

Vs.Bias voltage

30 35 40 45 50

5

10

15

202530

30 35 40 45 50

5

10

15

202530

30 35 40 45 50

5

10

15

202530

30 35 40 45 50

5

10

15

202530

30 35 40 45 50

5

10

15

202530

30 35 40 45 50

5

10

15

202530

30 35 40 45 50

5

10

15

202530

60

50

4025

15

5Vbias=0

Exponential-like decay outside the highly efficient depletion

region

2ee

eee

cm/V)3.057.2( : lifetimeMobility

m)17.057.2(DL :lengthdiffusion Electron

A. Lo Giudice et al, Physica Status Solidi Rapid Research Letters 5 (2011) 80-82

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CHARGE SHARING IN MULTIELECTRODE DEVICES

positioninitial

positionfinal VV

qQ

The induced charge Q at the sensing electrode is given by the difference in the weighting potentials between any two positions (rA and rB) of the moving charge

Actual potential Weighting potential

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Sensitive electrode

66

Actual potential

Sensitive electrode

02468

10121416

0,0

0,5

1,0

1,5

2,0

2,5

CH

AR

GE

time

CU

RR

ENT

time

positioninitial

positionfinal VV

qQ


67

positioninitial

positionfinal VV

qQ

Sensitive electrode


0

2

4

6

8

10

12

0.00

0.05

0.10

0.15

0.20

0.25

CH

AR

GE

time

CU

RR

ENT

time

68

Sensitive electrode


-4

-3

-2

-1

0

1-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

CH

AR

GE time

CU

RR

ENT

time

positioninitial

positionfinal VV

qQ

69

Sensitive electrode


-1,0-0,8-0,6-0,4-0,20,00,20,40,60,81,0

-0,04

-0,02

0,00

0,02

0,04

CH

AR

GE

time

CU

RR

ENT

time

positioninitial

positionfinal VV

qQ

Trieste 14.08.2012

IBIC map1.5 MeV H+

ElectrostaticPotential map

Vbias=100V

E.Vittone et al. Nuclear Instruments and Methods in PhysicsResearch B 266 (2008) 1312–1318.

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71

Weighting potential maps

S SG

S SG

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72

Calculated CCE maps10 V

70 V

130 V

0 , 2 0 0 00 , 2 5 0 00 , 3 0 0 00 , 3 5 0 00 , 4 0 0 00 , 4 5 0 00 , 5 0 0 00 , 5 5 0 00 , 6 0 0 00 , 6 5 0 00 , 7 0 0 00 , 7 5 0 00 , 8 0 0 00 , 8 5 0 00 , 9 0 0 00 , 9 5 0 01 , 0 0 0

0 1CCE

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-60 -40 -20 0 20 40 600.20.30.40.50.60.70.80.91.0

CC

E

10 V

20 V30 V40 V50 V70 V

Position (m)

0.9 MeV protons

-60 -40 -20 0 20 40 600.20.30.40.50.60.70.80.91.070 V

50 V

30 V20 V

10 V

Position (m)

40 V

-60 -40 -20 0 20 40 600.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Position (m)

10 V

20 V30 V40 V50 V70 V

-60 -40 -20 0 20 40 600.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

CC

E

Position (m)

A

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0,2

0,3

0,4

0,5

0,6

0,7

-60 -40 -20 0 20 40 60

CC

E

Position (m)

50 V60 V

30 V20 V

CC

E

10 V

-60 -40 -20 0 20 40 600,2

0,3

0,4

0,5

0,6

0,7

110 V120 V130 V

90 V80 V70 V

-60 -40 -20 0 20 40 600.20.30.40.50.60.70.80.91.0

CC

E

10 V

20 V30 V40 V50 V70 V

Position (m)

-60 -40 -20 0 20 40 600.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

CC

E

Position (m)

A

0.9 MeV protons 1.5 MeV protons

Trieste 14.08.2012

-70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

130 V

1500 keVCC

E

Position (m)

900 keV

S SG

10 20 30 40 50 60

0,2

0,3

0,4

0,5

0,6

0,7 900 keVConfiguration A

1500 keVConfiguration A

10 20 30 40 50 60

0,2

0,3

0,4

0,5

0,6

0,7

900 keVConfiguration B

CC

E

Position (m)

The electrode edges are highlighted by the vertical black line.

CCE profile detailshole diffusion length = 8.7 m. hole lifetime = p = 250 ns

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76

Horizontal electric field

positioninitial

positionfinal VV

qQ

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77

2 MeV He+

CCE AS FUNCTION OF ION STRIKE POSITION

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78

2 MeV He+

ION STRIKE POSITIONAS FUNCTION OF CCE

POSITION SENSITIVE DETECTOR

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A SUB-MICROMETER POSITION SENSITIVE DETECTOR

J. Forneris et al. Modeling of ion beam induced charge sharing experiments for the design of high resolution position sensitive detectors, Submitted to NIMB

2 MeV He beam @ NEC 5U Pelletron, Melbourne1 m spot size

400 nm resolution

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80

IBIC(Ion Beam Induced Charge Collection)

Control of in-depth generation profile

Suitable for finished devices (bulk analysis).

Micrometer resolution

CCE profiles: Active layer extension; Diffusion length

Robust theory; FEM and MC approaches

Analysis of multi-electrode devices

In-situ analysis of radiation damage

Analytical technique suitable for the measurement of transport properties in semiconductor materials and devices

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81

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