j.p. balbuena, g. pellegrini, r. bates, c. fleta, m. lozano, m. ullán

6th Trento Workshop on Advanced Silicon Radiation Detectors 1/16

J.P. Balbuena Instituto de Microelectrónica de Barcelona IMB-CNM (CSIC)

J.P. Balbuena, G. Pellegrini, R. Bates, C. Fleta, M. Lozano, M. Ullán

Semiconductor radiation detectors groupInstitut de Microelectrònica de Barcelona

Centre Nacional de Microelectrònica - CSICSpain

3rd March 2011

Simulations of 3D-DDTCSilicon detectors

Simulations of 3D-DDTCSilicon detectors



Blocks Columns Increments Transitions Hypertext

11 Motivation

22 Simulation: Layout and parameters

33 Simulation: Electric field

44 Simulation: Charge multiplication

55 Conclusions/Future work




11 Motivation







3D-DDTC measurementsIrradiated 3D detectors present Charge multiplication effect:

ObjectiveDevelop 3D detectors with Charge multiplication effect for low Bias voltages before irradiation by changing the bulk doping concentration.

above 150V for p-type above 260V for n-type

[M. Köhler, University of Freiburg, Germany]




11 Motivation







Geometry- pitch: 80 µm- wafer thickness: 285 µm- column depth: 250 µm- column diameter: 10 µm

Doping levels- n+ columns: 1019 cm-3

- p+ columns: 1019 cm-3

- p-stop: 1018 cm-3

- Si/SiO2 charge: 5·1011 cm-2

P-type

p+ p+

p+ p+

n+



Geometry- pitch: 80 µm- wafer thickness: 285 µm- column depth: 250 µm- column diameter: 10 µm

Doping levels- n+ columns: 1019 cm-3

- p+ columns: 1019 cm-3

- Si/SiO2 charge: 5·1011 cm-2

N-type

n+ n+

n+ n+

p+



Physics ModelMobility Doping dependance, High Electric field

saturation

Generation and Recombination Doping dependant Shockley-Read-Hall Generation recombination, Surface recombination model

Impact ionization University of Bologna impact ionization model

Tunneling Band-to-band tunneling, Hurkx trap-assisted tunneling

Oxide physics Oxide as a wide band gap semiconductor for mips (irradiated), interface charge accumulation

Radiation model Acceptor/Donor states in the band gap (traps)

[M. Benoit, Laboratoire de l’accélérateur linéar (LAL), Orsay, France]




11 Motivation







Electric Field (p-type)

0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

18

Ele

ctric

Fie

ld (

V/µ

m)

Distance (µm)

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm

Cut at z = 142,5 µm for Vbias

= 150 V

n+

p+

0 50 100 150 200 250 30002468

101214161820222426

Ele

ctric

Fie

ld (

V/µ

m)

Reverse Bias (V)

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm 50 ·cm

Cut at z = 35 µm

0 50 100 150 200 250 30002468

101214161820222426

Ele

ctric

Fie

ld (

V/µ

m)

Reverse Bias (V)

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm 50 ·cm

Cut at z = 142,5 µm

0 50 100 150 200 250 3000

5

10

15

20

25

30

35

Ele

ctric

Fie

ld (

V/µ

m)

Reverse Bias (V)

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm 50 ·cm

Cut at z = 250 µm



Electric Field (n-type)

0 10 20 30 40 50 600

2

4

6

8

10

12

14

16

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm 50 ·cm

Ele

ctric

Fie

ld (

V/µ

m)

Distance (µm)

Cut at z = 142,5 µm for Vbias

= 150 V

n+

p+

0 50 100 150 200 250 30002468

101214161820222426

Ele

ctric

Fie

ld (

V/µ

m)

Reverse Bias (V)

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm 50 ·cm

Cut at z = 35 µm

0 50 100 150 200 250 30002468

101214161820222426

Ele

ctric

Fie

ld (

V/µ

m)

Reverse Bias (V)

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm 50 ·cm

Cut at z = 142,5 µm

0 50 100 150 200 250 30002468

10121416182022242628303234363840

Ele

ctric

Fie

ld (

V/µ

m)

Reverse Bias (V)

1000 ·cm 500 ·cm 300 ·cm 200 ·cm 100 ·cm 50 ·cm

Cut at z = 250 µm



Using PowerPointto Typeset Nice Presentations


11 Motivation







0 200 400 600 800 10000

100

200

300

Vol

tage

(V

)

Resistivity (·cm)

VFD

p-type

V (Emax

~ 14 V/µm) p-type

VFD

n-type

V (Emax

~ 14 V/µm) n-type

Charge multiplication

Compromise between low full depletion voltages and high enough voltages for Charge multiplication

0 100 200 300 400 500 600

16000

20000

24000

28000

32000

36000

40000

Cha

rge

Col

lect

ed (

elec

tron

s)

Resistivity (·cm)

p-type (Vbias

=200V)

n-type (Vbias

=100V)

V = 150 V for both n and p-type

ρn = 100 Ω·cm ρp = 200 Ω·cm

MIP 22800 electrons

Charge multiplication



Charge multiplication in the irradiated 3D model

Doping concentration: Neff = 7·1011 cm-3 (p-type)

Fluence: Φeq = 2·1015 neq/cm2

0 10 20 30 40 50 600

2

4

6

8

10

12

14

Vbias

= 200 V

Vbias

= 250 V

Ele

ctric

fie

ld (

V/µ

m)

Distance (µm)

0 100 200 300

16000

18000

20000

22000

24000

26000

28000

30000

Cha

rge

Col

lect

ed (

elec

tron

s)

Bias voltage (V)

eq

= 2 x 1015 n/cm2

Electric field compatible with Charge multiplication for 250V

Unexpected reduction of the charge collected for 250V !!

0 50 100 150 200 250 3004x10-10

5x10-10

6x10-10

7x10-10

8x10-10

9x10-10

10-9

Leak

age

curr

ent

(A)

Bias voltage (V)

Qox

= 5·1011 cm-2

Qox

= 1012 cm-2

Qox

= 2·1012 cm-2

Qox

= 3·1012 cm-2

Interface charge: Qox = 5·1011 cm-2



Using PowerPointto Typeset Nice Presentations


11 Motivation







Conclusions

Future work

Obtained charge multiplication effect in both n and p-type substrates without irradiation

Complete the study on multiplication effect for different doping levels at different biasing voltages

Solve problems of charge multiplication in the irradiated 3D model.

j.p. balbuena, g. pellegrini, r. bates, c. fleta, m. lozano, m. ullán

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