Transcript MCNP Simulation

Study of irradiated 3D detectors
Patrick Roy
G. Pellegrini, A. Al-Ajili, L. Haddad, J. Melone,
V. O'Shea, K.M. Smith, V. Wright, M. Rahman
10/09/2002
P. Roy
Overview
Introduction
Fabrication:
-Dry etching
-Laser machining
-Photoelectrochemical etching
-Electrical contacts
Results:
-Before irradiation
-After irradiation
Conclusion
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Introduction
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Motivation
2000
s ta n d a rd s ilic o n
1500
1500
6000 e for B-layer
1000
1000
dep
( 2 00 m m ) [ V ]
2000
V
operation voltag e: 600 V
500
500
o x y g e n a te d s ilic o n
0
1
2
3
4
5
6
t im e [y e a rs ]
7
8
9
• 3D
10
detector!
Damage projection for the ATLAS B-layer
(3rd RD48 STATUS REPORT CERN LHCC 2000-009, LEB Status Report/RD48, 31 December 1999).
Vdep  qw2Neff/2e
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Fabrication steps
Creation of the holes
Dry etching
Laser drilling
PEC etching
Creation of the electrodes
Shottky-Schottky
n-Shottky
p-n junction
Connection to the electronics
Wire bonding
Bump bonding
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Dry etching
Inductively Coupled Plasma
•Mask: photoresist
•Gas: SF6
•Coating: C4F8
•Diameter: 10 mm
•Spacing: 85 mm
•Depth:
130 mm
•Etch time: 100 minutes
Aspect ratio 13:1
Expect < 20:1
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Laser machining in Si
Ti:Sapphire laser (TOPS facility at Strathclyde University*)
3 mJ pulse with duration of 40 fs at 1 kHz repetition rate
810 nm wavelength or 405 nm wavelength (doubling crystal)
•Diameter:
Front: 8 -10 mm
Back: 6 - 8 mm
•Spacing: 85 mm
•Depth: 200 mm
•Power: 75 mW
•Time: 5 sec/holes
Aspect ratio 25:1
* In
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collaboration with D.A. Jaroszynski and D. Jones of Strathclyde University
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PEC etching in Si
•Mask: 100 nm l/s SiN
•Solution: 2.5% aqueous HF
•Diameter: 10 mm
•Spacing: 25 mm
•Depth:
120 mm
•Etch time: 480 minutes
Aspect ratio 12:1
Expect > 100:1
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Electrical contacts
•Metal evaporation:
Ti (33 nm)
Pd (33 nm)
Au (150 nm)
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•Tracks of Al (150 nm)
(over the SiO2 layer)
•Wire bonding
(25 mm wire)
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Results with a particles
5.5 MeV alpha in Si
5.5 MeV alpha in GaAs
80
50 V
70 V
80 V
10 V
30 V
70
50 V
120 V
60
Signal (counts)
Signal (counts)
120
45 V
80
50
40
30
20
10
40
0
50
100
150
200
250
300
Channel
0
100
150
200
250
300
350
Charge Collection Efficiency
Channel
60%
Resolution
~27%
~54%
CCE
~60%
~47%
CCE
Material
Silicon
GaAs
50%
40%
Silicon
30%
GaAs
20%
10%
0%
0
20
40
60
80
100
120
Bias (volts)
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Results with X-Ray in GaAs
1000
750
Tb (45 keV)
Am (60 keV)
600
5V
10 V
15 V
20 V
600
25 V
Signal (counts)
Signal (counts)
800
Tb (45 keV)
Mo (17 keV)
Ag (22 keV)
Ba (32 keV)
400
30 V
450
35 V
40 V
300
200
150
0
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
Energy (keV)
0
30
40
50
60
70
80
90
Channel
Resolution ~44%
CCE ~70%
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100
Irradiation at PSI
Irradiation with 300 MeV/c p at PSI (Villigen*)
Bunch of 1 ns every 19 ns.
Flux of 1014 p/cm2/day.
Fluences between 1012 and 1014 p/cm2.
Irradiation performed by K. Gabathuler, M. Glaser and M. Moll.
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Leakage current
f = 1012 p/cm2
3.5E-04
7.5E-04
3.0E-04
6.5E-04
2.5E-04
5.5E-04
Current (A)
Current (A)
Before irradiation
2.0E-04
1.5E-04
1.0E-04
4.5E-04
3.5E-04
2.5E-04
5.0E-05
1.5E-04
0.0E+00
5.0E-05
-5.0E-05
-5.0E-05
-75
-50
-25
0
25
50
-75
75
-50
-25
0
25
50
75
Bias (volts)
Bias (volts)
f = 1014 p/cm2
f = 1013 p/cm2
2.0E-04
3.5E-04
3.0E-04
2.5E-04
Current (A)
Current (A)
1.5E-04
1.0E-04
5.0E-05
2.0E-04
1.5E-04
1.0E-04
5.0E-05
0.0E+00
0.0E+00
-5.0E-05
-1.0E-04
-5.0E-05
-35
-10
15
40
Bias (volts)
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65
90
-1.5E-04
-100
-50
0
50
100
Bias (volts)
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Fabrication comparison
Aspect ratios
Technique
currently
expected
Sidewall
damages
Dry etching
Laser drilling
PEC etching
13:1
25:1
12:1
<20:1
~50:1
>100:1
yes
yes
no
Metal evaporation
n or p type doping
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Simple process
Complex process
Standard process
Expensive
Most promising
Good for GaAs
Good for Si
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Conclusion
Dry etching ==> 13:1 in silicon
Laser machining ==> 25:1 material independent
PEC etching ==> 12:1 in silicon
Irradiated working devices in Si and GaAs
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In development
Run II with fs laser in GaAs and SiC
Improvement of PEC etching
Improvement of dry etching
Connection to DAC readout chip
Better contacts
Proton irradiation of samples
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