ELECTRONIC PROPERTIES OF IIA HPHT DIAMOND SAMPLES … · NDT2 NDT6 ge current [A] applied bias [V]...

5th ADAMAS Workshop, Darmstadt, Germany 15-16/12/2016 | Pomorski Michal

ELECTRONIC PROPERTIES OF IIA HPHT DIAMOND SAMPLES FROM NEW DIAMOND TECHNOLOGY

| 25th ADAMAS Workshop, Darmstadt, Germany 15-16/12/2016 | Pomorski Michal

WHY TO BOTHER WITH HPHT DIAMONDS

? What about electronic quality ?

| 35th ADAMAS Workshop, Darmstadt, Germany 15-16/12/2016 | Pomorski Michal

OUTLINE

1. NDT, Samples and Structural Quality

2. Current-Voltage Characteristics

3. Charge Collection Characteristics

4. TCT Characteristics

5. Summary

| 4

HPHT DIAMONDS AND NDT


Multiseeds growth15m

m

25mm

Diamond cube 4x4 mm current 200 in three years 750



growth rate

HPHT

| 5



http://ndtcompany.com/

| 6



http://ndtcompany.com/

| 7

SAMPLES AND STRUCTURAL QUALITY


Six HPHT diamond plates (NDT1-NDT6)

- sizes: 4 x 4 mm and ~100 µm thickness

- sizes: 4.5 x 4.5 mm and ~100 µm thickness

- from six different production runs

- <100>, monosectoral, Iia high purity

Standard procedure (used for e6 CVD) of samples metallization:

cleaning in hot acid solution H2SO4+KNO3 (boiling); DI water; IPA; drying

Al contacts by PVD sputtering power 200W, bias 1000V, Argon 10-3 mbar

with shadow masks, parallel plates

only two (NDT2 and NDT6) samples give promising results

| 8

SAMPLES AND STRUCTURAL QUALITY- BIREFRINGENCE


NDT Iia HPHT E6 CVD (recently processed)

no birefringence contrast

for all six samples

strong to moderate

biref. contrast

Crossed-polarizers imaging before metallization

| 9

CURRENT VOLTAGE CHARACTERISTICS


some general observations IIa HPHT for I-V @ RT (more than six samples):

- majority of the samples are not resistive, high leakage current (µA) at low bias (0.1V/µm)

- some samples are highly resistive but gives no sign of charge transport

- some samples ‘leak’, but give moderate to high quality charge transport properties

- one sample gives high resistivity and very good charge transport properties

| 10

CURRENT VOLTAGE CHARACTERISTICS


-600 -500 -400 -300 -200 -100 0 100 2001f

100f

10p

1n

100n

10µ

1m

-6 -5 -4 -3 -2 -1 0 1 2

applied electric field [V/m]

NDT2

NDT6

lea

ka

ge

cu

rre

nt

[A]

applied bias [V]

| 11

CHARGE COLLECTION PROPERTIES


- 5.5 MeV α-particles (Am-241 source, 4kBq)

- collimated elctrodes

- measurements in primary vacuum, dark

- majority of e or h drift (polarity of HV)

- coolFET A250 amptek preamp. (2.5 ns rise)

- 3 µs shaping time

- pocket MCA or DSO as DAQ

Set-up:Measurement conditions:

| 12

CHARGE COLLECTION PROPERTIES - NDT2


0 200 400 600 8000

10

20

30

40

50

60

70

80

90

100

110

120

10V (0.1V/m)

20V (0.2V/m)

30V (0.3V/m)

40V (0.4V/m)

counts

ADC channel [au]

0 200 400 600 8000

1

2

3

4

5

6

7

8

9

10

10V

20V

30V

40V

50V

counts

ADC channel au

electrons driftholes drift

5.5 α-particles spectra vs. detector bias

-1,2 -0,8 -0,4 0,0 0,4 0,8 1,2

-100

-80

-60

-40

-20

0

20

40

60

80

100

CC

E %

Applied electric field [V/m]

holes drift

electrons drift

| 13



950000 960000 970000 980000 990000 1000000

0

1

2

3

4

5

6

7

8

sig

na

l am

plit

ude [V

]

event number

997000 998000 999000 10000000

1

2

3

4

5

6

7

sig

na

l am

plit

ude [V

]event number

long term stability under 5.5 α-particles irradiation

weak polarization strong polarization

electrons driftholes drift

time

time

| 14



0 200 400 600 8000

10

20

30

40

50

60

70

80

90

100

10V (0.1 V/m)

20V

30V

50V

80V (0.8 V/m)

counts

ADC channel [au]

0 200 400 600 8000

5

10

15

20

25

30

35

50 V (0.5 V/m)

80 V

120 V (1.2 V/m)

co

un

ts

ADC channel [au]

5.5 α-particles spectra vs. detector bias

holes drift electrons drift

-1,2 -0,8 -0,4 0,0 0,4 0,8 1,2

-100

-80

-60

-40

-20

0

20

40

60

80

100

NDT2

NDT6

CC

E %

Applied electric field [V/m]

holes drift

electrons drift

| 15



990000 995000 10000000

1

2

3

4

5

6

7

sig

na

l a

mp

litu

de

[V

]

event number

960000 980000 10000000

1

2

3

4

5

6

7

sig

na

l am

plit

ude [V

]event number

holes drift electrons drift

stable - no polarization strong polarization

long term stability under 5.5 α-particles irradiation

time time

| 16

CHARGE COLLECTION PROPERTIES – BEST OF NDT2 NDT6


0 200 400 600 8000

20

40

60

80

100

holes @ 0.8 V/m

electrons @ 1.2 V/m

co

un

ts

ADC channel [au]

0 200 400 600 8000

20

40

60

80

100

120 holes @ 0.4 V/m

electrons @ 0.5 V/m

coun

ts

ADC channel [au]

600 620 640 660 680 7000

20

40

60

80

100

counts

ADC channel [au]

EFWHM

=0.9%

NDT2NDT6

NDT6

spectroscopic grade

(holes drift)

| 17

CHARGE COLLECTION PROPERTIES


-200 0 200 400 600 800

0,00

0,02

0,04

0,06

0,08

0,10

0,12

NDT3-holes

NDT6-holes

e6 EG scCVD

NDT6-electrons

sig

na

l a

mp

litu

de

[V

]

time [ns]

CoolFET A250 Amptek preamp

deep trapping for electrons polarization

shallow trapping for holes all de-trapped within 3 µs @ RT (~0.3 eV)

de-trapping probability @ RT

| 18

TCT


- 5.5 MeV α-particles (Am-241 source, 4kBq)

- collimated elctrodes

- measurements in primary vacuum

- majority of e or h (polarity of HV)

- CVIDEC C2 fast amplifier

- DSO as DAQ

Set-up:Measurements conditions:

| 19

TCT – NDT6


-1 0 1 2 3 4 5 6-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

electrons

sig

na

l a

mp

litu

de

[V

]

time [s]

20V

150V

- fast rise and decay times – nice time detector

- no flat top, high amplitude (built-in field)

- drift velocity seems faster than CVD

(but thin sample, internal field need tct on thicker

samples)

- no de-trapping visible

-1 0 1 2 3 4 5 6-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

150V

sig

na

l a

mp

litu

de

[V

]

time [ns]

holes

10V

| 20

TCT – NDT6


-2 0 2 4 6 8 10-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

holes

electrons

sig

na

l a

mp

litu

de

[V

]

time [ns]

0 2 4 6 8 10

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

NDT6 (97 m) electrons

NDT6 (97 m) holes

e6CVD (500 m) electrons

sig

na

l am

plit

ude [V

]

time [ns]

-2 0 2 4 6 8 10-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

holes

electrons

sig

na

l a

mp

litu

de

[V

]

time [ns]

150 V

20 V 80 V

-2 0 2 4 6 8 10

-5

-4

-3

-2

-1

0

e6 CVD 500m

holes NDT6

electrons NDT6

inte

gra

ted T

CT

[au]

time [ns]

puzzling: no de-trapping visible

| 21

SUMMARY


(Very) Preliminary characteristics of Iia HPHT samples from NDT were performed:

I-V: majority of the samples are conductive (impossible to apply bias)

- some of them have acceptable level of leakage current

- rarely samples are highly resistive

CCE: - for holes drift reaches 100%; for electrons drift reaches 80%

- stable operation for holes drift, with spectroscopic quality

deep trapping for electrons leads to polarization, shallow trapping for holes

all charge released @ RT within shaping time used (3micros)

TCT: - fast signals including rise and decay time (no slow component)

- holes faster than electrons, drift velocity seems higher than CVD

Only two samples out of six give promising results

In current state NDT samples can be used for some detector applications

(if same or better quality than NDT6): eg. traversing particles, time measurements,

tagging, spectroscopy with majority of holes drift

| 22

Thank you very much for your kind attention !

Commissariat à l’énergie atomique et aux énergies alternatives

Institut List | CEA SACLAY NANO-INNOV | BAT. 861 – PC142

91191 Gif-sur-Yvette Cedex - FRANCE

www-list.cea.fr

Établissement public à caractère industriel et commercial | RCS Paris B 775 685 019

| 24

SAMPLES AND STRUCTURAL QUALITY


| 25AMDE 2016 Conference, Gunma University, Japan 09/12/2016 | Pomorski Michal

BNCD SEE MEMBRANES

100 nm

Silicon nitride

windows

nanoseeding

BNCD coated

silicon nitride windows

CVD grwoth

- seeding with diamond

nanoparticles 5-20nm

in PDDAC

- MVCVD diamond growth (H2/CH4)

- temperature ~ 500-800 C

- boron doping (TMP)

up to metallic conductivity

- few hours processing

- commercial product

- 150 nm thick membrane

- not expensive

NEA

| 26AMDE 2016 Conference, Gunma University, Japan 09/12/2016 | Pomorski Michal

ACTIVE SCCVD DIAMOND MEMBRANE – 3 MEV PROTONS

diamond as a soild-state ionization chamber

ELECTRONIC PROPERTIES OF IIA HPHT DIAMOND SAMPLES … · NDT2 NDT6 ge current [A] applied bias [V]...

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