04/21/2304/21/23 Workshop on p-type detectorsWorkshop on p-type detectors 11

Comprehensive Radiation Comprehensive Radiation Damage Modeling of Silicon Damage Modeling of Silicon

DetectorsDetectors

Petasecca M.Petasecca M.1,31,3, Moscatelli F., Moscatelli F.1,2,31,2,3, Scarpello C., Scarpello C.11, , Passeri D.Passeri D.1,31,3, , Pignatel G.U.Pignatel G.U.1,31,3

11DIEI - DIEI - Università di PerugiaUniversità di Perugia, via G.Duranti,93 - Italy , via G.Duranti,93 - Italy 22IMIMM-CNR sez.di Bologna, via Gobetti 101 – ItalyM-CNR sez.di Bologna, via Gobetti 101 – Italy

33INFN sez. Perugia – via Pascoli, 10 – ItalyINFN sez. Perugia – via Pascoli, 10 – Italy

In the framework of RD50-CERN CollaborationIn the framework of RD50-CERN Collaboration

22

OUTLINEOUTLINE

development of the development of the 3-level3-level radiation radiation damage damage modelmodel for for n-typen-type silicon silicon

development of the development of the 2-level2-level radiation radiation damage model for damage model for p-typep-type silicon silicon

simulation of Charge Collection simulation of Charge Collection Efficiency Efficiency (CCE)(CCE) in irradiated (n-type) in irradiated (n-type) silicon detectorssilicon detectors

33

Simulation toolSimulation tool::

ISE-TCAD – discrete time and space solution of ISE-TCAD – discrete time and space solution of drift/diffusion and continuity equationsdrift/diffusion and continuity equations

Damage modelDamage modelllinging::

- Deep levels: E- Deep levels: Ett, , nn and and pp

- SRH statistics- SRH statistics

- U- Uniform density of defect concentrationniform density of defect concentration

Radiation damage Effects to simulate:Radiation damage Effects to simulate:-The increasing of the Leakage CurrentThe increasing of the Leakage Current-The increasing of the Full Depletion VoltageThe increasing of the Full Depletion Voltage-The decreasing of the Charge Collection The decreasing of the Charge Collection EfficiencyEfficiency

44

Simulation setupSimulation setupSimulated device Simulated device structure and structure and parameters:parameters:

Doping profiles:Doping profiles:

N and P dopedN and P doped substrates (7substrates (710101111 cm cm-3-3)) 6kΩcm6kΩcm..

Charge concentration at the Charge concentration at the silicon-oxide interface of :silicon-oxide interface of :

4 4 10101111 cm cm-3-3 pre-irradiation pre-irradiation 1 1 10101212 cm cm-3-3 post-irradiation post-irradiation

Optimized variable mesh Optimized variable mesh definitiondefinition Temperature = 300 KTemperature = 300 K D (thickness) = 50-100-300 D (thickness) = 50-100-300 umum

Guard Ring Diode Guard Ring

6µm40µm15µm9µm

D

Back

55

Simulation setupSimulation setup

Guard RingDiode- Variable mesh definition:

the mesh is better refined in correspondence of the critical points of the device to improve simulator performance.

- The typical electric field distribution at the depletion voltage of the diode.

66

Level [eV]Level [eV] AssignmentAssignment σσnn [cm [cm-2-2]] σσpp [cm [cm-2-2]] ηη [cm[cm-1-1]]

EEcc-0.42-0.42 VVVV(-/0)(-/0) 11·10·10-16-16 88·10·10-15-15 26*26*

EEcc-0.50-0.50 VVOVVO(-/0)(-/0) 11·10·10-16-16 11·10·10-15-15 0.10.1

EEvv+0.36+0.36 CCiiOOii(+/0)(+/0) 1·101·10-15-15 1·101·10-16-16 11

The n-type (modified) 3-Level The n-type (modified) 3-Level Radiation Damage Model*Radiation Damage Model*

* Angarano, Bilei, Giorgi, Ciampolini, Mihul, Militaru, Passeri, Scorzoni, CERN, Geneve, CMS CR 2000/006, 2000

σσn/pn/p [cm [cm-2-2]: cross section]: cross section

ηη [cm [cm-1-1]: introduction rate]: introduction rate

* ηη=26 takes into account cluster defects

77

Level [eV]Level [eV] AssignmentAssignment σσnn [cm [cm-2-2]] σσpp [cm [cm-2-2]] ηη [cm[cm-1-1]]

EEcc-0.42-0.42 VVVV(-/0)(-/0) 11·10·10-16-16 88·10·10-15-15 26*26*

EEcc-0.50-0.50 VVOVVO(-/0)(-/0) 11·10·10-16-16 11·10·10-15-15 0.10.1

EEvv+0.36+0.36 CCiiOOii(+/0)(+/0) 1·101·10-15-15 1·101·10-16-16 11

The n-type (modified) 3-Level The n-type (modified) 3-Level Radiation Damage Model*Radiation Damage Model*

* [Angarano, Bilei, Giorgi, Ciampolini, Mihul, Militaru, Passeri, Scorzoni, CERN, Geneve, CMS CR 2000/006, 2000]

α [A/cm] simulated

5.25±0.02·10-17

α [A/cm] experimental*

5.4÷6.7·10-17

* * ηη = 26 takes into account cluster defects

α 80/60 [A/cm]

ROSE-RD48

4.0·10-17

88

(*) [N. Zangenberg, et al.,Nuc. Instr. And Meth B 186 (2002) 71-77](*) [N. Zangenberg, et al.,Nuc. Instr. And Meth B 186 (2002) 71-77]

[M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594][M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594]

Level*Level* Ass.Ass.σσnn [cm [cm-2-2]]

ExperimentaExperimental*l*

σσpp [cm [cm-2-2]]ExperimentaExperimenta

l*l*

σσnn

[cm[cm-2-2]]****σσpp

[cm[cm-2-2]]ηη

[cm[cm-1-1]]

EEcc--0.42eV0.42eV

VVVV(-/0)(-/0) 22·10·10-15-15 22·10·10-15-15 22·10·10-15-15 22·10·10-13-13 2.422.42

ββ [cm[cm-1-1] ] experimentalexperimental

4,04,0±0,4 ·10±0,4 ·10-3-3

** 2 order of magnitude higher

ββ [cm[cm-1-1] ] simulatedsimulated

3,723,72 ·10 ·10-3-3

The The p-typep-type One-Level Radiation One-Level Radiation Damage ModelDamage Model

Measures extracted from [M. Lozano, et al., RD50 workshop, Firenze, Oct 2004]

99

(*) [N. Zangenberg, et al.,Nuc. Instr. And Meth B 186 (2002) 71-77](*) [N. Zangenberg, et al.,Nuc. Instr. And Meth B 186 (2002) 71-77]

[M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594][M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594]

Level*Level* Ass.Ass.σσnn [cm [cm-2-2]]

ExperimentalExperimental**

σσpp [cm [cm-2-2]]ExperimentalExperimental

**

σσnn

[cm[cm-2-2]] σσpp

[cm[cm-2-2]]ηη

[cm[cm-1-1]]

EEcc--0.42eV0.42eV

VVVV(-/0)(-/0) 22·10·10-15-15 22·10·10-15-15 22·10·10-15-15 22·10·10-13-13 2.422.42

αα [ [A/cm] A/cm] simulatedsimulated

6,66,6 ·10 ·10-17-17

αα [ [A/cm] A/cm] experimentalexperimental

6,526,52±0,11 ·10±0,11 ·10-17-17

The p-type One-Level Radiation The p-type One-Level Radiation Damage ModelDamage Model

Measures extracted from [M. Lozano, et al., RD50 workshop, Firenze, Oct 2004]

1010

The p-type Two-Level Radiation Damage The p-type Two-Level Radiation Damage ModelModel

[(**) Levels selected from: M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594[(**) Levels selected from: M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594

S.Pirolo et al., Nuc. Instr. And Meth. A 426 (1996) 126-130 ]S.Pirolo et al., Nuc. Instr. And Meth. A 426 (1996) 126-130 ]

* 1 order of magnitude higher

ββ [cm[cm-1-1] ] experimentalexperimental

4,04,0±0,4 ·10±0,4 ·10-3-3

ββ [cm[cm-1-1] ] simulatedsimulated

3.983.98·10·10-3-3

Level**Level** Ass.Ass.σσnn [cm [cm-2-2]]

ExperimentaExperimentall

σσpp [cm [cm-2-2]]ExperimentalExperimental

σσnn

[cm[cm-2-2]]**σσpp

[cm[cm-2-2]]ηη

[cm[cm-1-1]]

EEcc--0.42eV0.42eV

VVVV(-/0)(-/0) 22·10·10-15-15 22·10·10-15-15 22·10·10-15-15 22·10·10-14-14 1.613*1.613*

EEcc--0.46eV0.46eV

VVVVVV(-/0)(-/0) 55·10·10-15-15 55·10·10-15-15 55·10·10-15-15 55·10·10-14-14 0.96*0.96*

Measures extracted from [M. Lozano, et al., RD50 workshop, Firenze, Oct 2004]

**ηη Moll = 0.91.8

1111

αα [ [A/cm] A/cm] simulatedsimulated

3.753.75·10·10-17-17

αα [ [A/cm] A/cm] reported (*?)reported (*?)

6,526,52±0,1 ·10±0,1 ·10-17-17

Measures extracted from [M. Lozano, et al., RD50 workshop, Firenze, Oct 2004]

The p-type Two-Level Radiation Damage The p-type Two-Level Radiation Damage ModelModel

Level**Level** Ass.Ass.σσnn [cm [cm-2-2]]

ExperimentaExperimentall

σσpp [cm [cm-2-2]]ExperimentalExperimental

σσnn

[cm[cm-2-2]]**σσpp

[cm[cm-2-2]]ηη

[cm[cm-1-1]]

EEcc--0.42eV0.42eV

VVVV(-/0)(-/0) 22·10·10-15-15 22·10·10-15-15 22·10·10-15-15 22·10·10-14-14 1.6131.613

EEcc--0.46eV0.46eV

VVVVVV(-/0)(-/0) 55·10·10-15-15 55·10·10-15-15 55·10·10-15-15 55·10·10-14-14 0.960.96

[(**) Levels selected from: M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594 [(**) Levels selected from: M. Ahmed, et al., Nuc. Instr. And Meth A 457 (2001) 588-594

S.Pirolo et al., Nuc. Instr. And Meth. A 426 (1996) 126-130 ]S.Pirolo et al., Nuc. Instr. And Meth. A 426 (1996) 126-130 ]

* 1 order of magnitude higher

1212

LevelLevel Ass.Ass.σσnn [cm [cm-2-2]]

ExperimentExperimentalal

σσpp [cm [cm-2-2]]

ExperimentExperimentalal

σσnn

[cm[cm-2-2]]

**σσpp

[cm[cm-2-2]]

ηη

[cm[cm-1-1]]

EEcc-0.42eV-0.42eV VVVV(-/0)(-/0) 22·10·10-15-15 22·10·10-15-15 22·10·10-15-15 22·10·10-14-14 1.6131.613

EEcc-0.46eV-0.46eV VVVVVV(-/0)(-/0) 55·10·10-15-15 55·10·10-15-15 55·10·10-15-15 55·10·10-14-14 0.960.96

EEvv+0.36eV+0.36eV ? C? CiiOOii?? 2.5·102.5·10-14-14 2.5·102.5·10-15-15 2.5·102.5·10-14-14 2.5·102.5·10-15-15 0.90.9

ββ [cm[cm-1-1] ] experimentalexperimental

4,04,0±0,4 ·10±0,4 ·10-3-3

ββ [cm[cm-1-1] simulated] simulated

3.983.98·10·10-3-3

* 1 order of magnitude higher

The p-type Three-Level Radiation Damage The p-type Three-Level Radiation Damage Model: Model:

no improvement due to the donor defect levelno improvement due to the donor defect level

αα [ [A/cm] simulatedA/cm] simulated

3.753.75·10·10-17-17

αα [ [A/cm] A/cm] experimentalexperimental

6,526,52±0,11 ·10±0,11 ·10-17-17

Measures extracted from [M. Lozano, et al., RD50 workshop, Firenze, Oct 2004]

1313

CCE SimulationCCE Simulation

MIP: 80 e-h pairs/ µmcylinder diameter = 2µm

dttIQ )(

1414

CCE SimulationCCE Simulation

1515

CCE SimulationCCE Simulation

1616

CCE SimulationCCE Simulation

1717

CCE Simulation CCE Simulation

1818

CCE SimulationCCE Simulation

1919

CCE SimulationCCE Simulation

2020

* Measurements from Allport, Casse et al. NIMA 501 (2003)

146-152

CCE vs BIAS voltage for n-type silicon

Simulation data well reproduce experimental* measure at the fluences of 1·1014 n/cm2 and 2.5·1014 n/cm2

2121

CCE vs BIAS for n-type

Simulation data at Fluence of 1·1015 n/cm2 and 1·1016 n/cm2

Problem: the diode collects charge also in the not depleted area.At a fluence of 5·1014:Simulated CCE = 75%Estimated (*) = 55%

(*) [Bloch et al, NIMA 517 (2004) 121-127]

2222

CCE vs BIAS for n-type

Discussion about the ISE T-CAD Recombination Time model

REF

eff

effdop

doppn

kT

E

effinkT

E

effip

effiSRH

N

NN

ETF

eppenn

nnpR

he

traptrap

1

)(

),(

minmaxmin

/

2,

2,

2,

/

eqheeff

/

1

Default parameters of the Scharfetter model:

NREF=1016 cm-3, γ=1, τmin=0, τmax(e) =3 µs, τmax(h) =10 µs

βe [10-16 cm2/ns]

βh [10-16 cm2/ns]

5.16 + 0.16 5.04 + 0.16

where

From RD50 status Report (2004):

change the NREF parameter in order to obtain the correct value of the recombination time(*) J.G.Fossum, D.S. Lee, Solid-State Electronics, vol.25,no.8 (1982).

2323

Scharfetter

ISE T-CAD Recombination Time model

Default parameters:

NREF=1016 cm-3, γ=1,

τmin=0, τmax(e) =3 µs, τmax(h) =10 µs

)/(1)( minmax

minrefeff

effdopNN

N

(one pole in the TF)

Aim: modify/adapt the Scharfetter model to simulate the effect of deep-level defects on the reduction of carrier life-time

2424

ConclusionsConclusions Irradiated diodes have been analyzed considering a

three levels simulation model for p-type and n-type Si substrates:

The two-level model for the p-type and the three-level for n-type fit experimental data for the Leakage Current and Full Depletion Voltage

The CiOi acceptor level for p-type silicon seems to be un-influential (at Room Temperature)

The three-level for n-type fits CCE experimental data only for fluences up to 2.5·1014 n/cm2.

Scharfetter recombination time empirical model can be eventually adapted to fit CCE experimental data at higher fluences (first good point @1e15 n/cm2).