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KIT – University of the State of Baden-Wuerttemberg and
National Research Center of the Helmholtz Association
INSTITUT FÜR EXPERIMENTELLE KERNPHYSIK
www.kit.edu
CMS HPK Sensor Characterization
A. Dierlamm on behalf of the CMS Tracker Collaboration
A. Dierlamm
Institut für Experimentelle Kernphysik
2 17.09.2012 VERTEX 2012, Jeju, Korea
Outline
Sensor Requirements
HPK Campaign Intro
Mini strip sensors
IV, CV compared to diodes
Strip parameters
Charge collection
Cluster widths
Multi-geometry strip sensors
Strip capacitance study
Lorentz shifts
New sensor design: Fourfold segmented strip sensor with edge read-
out
A. Dierlamm
Institut für Experimentelle Kernphysik
3 17.09.2012 VERTEX 2012, Jeju, Korea
Requirements for Silicon Strip Sensors – I
Very high radiation hardness for up to 1.5e15neq/cm²
need well detectable signal possibly at ≤ 600V
need to study mixed irradiation fields as in the experiment, since oxygenated silicon material does show NIEL violation and we need to quantify the benefits
need to consider binary read-out
CMS Binary Chip might be operated at a threshold of around 1fC (~6240e-)
different cluster definition and resolution than analogue
0 10 20 30 40 50 60 70 80 90 100 11010
13
1014
1015
1016
1017
Flu
ence
(1/c
m²)
Radius (cm)
Z=0cm (barrel):
Charged hadrons
Neutral hadrons
Total
Z=250cm (end-cap):
Charged hadrons
Neutral hadrons
Total
3000fb-1
http://www.hep.ph.ic.ac.uk/~dmray/CBC_doc
umentation/CBC_status_Oct_2011.pdf
NIM A 623 (2010) 177–179
n-in-p FZ
A. Dierlamm
Institut für Experimentelle Kernphysik
4 17.09.2012 VERTEX 2012, Jeju, Korea
Requirements for Silicon Strip Sensors – II
Increased granularity to cope with higher track density
(PU ~100 or even ~200)
shorter strips, not necessarily smaller pitch (80µm – 100µm sufficient)
outer regions ~ 5cm long strips (currently 20cm)
inner region down to ~1mm to separate interactions (needed for contribution to L1
trigger)
optional: increased complexity of routing lines
integrated PA to reduce glass substrates
routing of inner strips to edge on sensors with four-fold segmentation
High PU event picture integrated PA
Fourfold segmented
strip sensor with
edge read-out
A. Dierlamm
Institut für Experimentelle Kernphysik
5 17.09.2012 VERTEX 2012, Jeju, Korea
Sensors
200µm
Fram
e (hyb
rids)
Hybrid
s
Fram
e (senso
rs)
Opto
Alu c
ontact
s
Power
Cooling
ASICs
Connector
Screws
HV
0
1
2
3
4
5
6
7
8
9
10
11
We
igh
t (g
)
0.0
0.1
0.2
0.3
0.4
0.5
X/X
0 (
%)
Requirements for Silicon Strip Sensors – III
Reduced material
material budget for new module concept is dominated by silicon weight
thinner sensors 200µm, 150µm?
also beneficial to reduce bias voltage and leakage current
but: less signal, brittle, more expensive
integrated PA to replace glass substrates
Total module mass: 29.0g
(320µm: 34.4g)
Total X/X0: 1.06%
(320µm: 1.33%)
2S module
Numbers from D. Abbaneo
A. Dierlamm
Institut für Experimentelle Kernphysik
6 17.09.2012 VERTEX 2012, Jeju, Korea
Purpose of measurement campaign
Investigate limits of radiation tolerance for various available silicon bulk materials for thicknesses ≤320µm
get information after pure proton and neutron irradiations as well as after mixed irradiations corresponding to expected mixture
Investigate performance and functionality of new sensor designs
Provide the Tracker Simulation Group with detailed information about: parameters like strip capacitance, collected charge, cluster width, resolution, Lorentz shift, leakage current
dependence on sensor design, material, bias voltage, irradiation fluence, annealing, temperature,…
Choice of sensor material and design is driven by the overall performance of the tracker and therefore also depends on the new module concept and read-out chip
To get consistent results we use wafers produced by one company with same process steps
irradiate samples for a given fluence together where possible
use one protocol to perform the measurements at several institutes
perform cross-calibrations of the participating institutes
A. Dierlamm
Institut für Experimentelle Kernphysik
7 17.09.2012 VERTEX 2012, Jeju, Korea
HPK Campaign
Wafer materials (total 164 wafers):
Float-zone
320µm, 200µm,
200µm deep diff.*, 120µm deep diff.*,
120µm on carrier,
200µm deep diff.* with 2. metal layer
Magnetic Czochralski
200µm
Epitaxial silicon
100µm, 70µm, 50µm
all as n-type and p-type
(with p-stop and p-spray strip isolation)
Characterizations are done before and after
irradiations (both with 23MeV protons @ KIT and
reactor neutrons @ JSI, Ljubljana)
* 320µm physical thickness; active thickness reduced by deep in-diffusion of back-side doping
Radius Protons Neutrons Ratio p/n Total Material
40cm 3 4 0.75 7.0 ≥ 200µm
20cm 10 5 2.00 15.0 ≥ 200µm
15cm 15 6 2.50 21.0 ≥ 200µm
10cm 30 7 4.29 37.0 ≤ 200µm
5cm 130 10 13.00 140.0 < 200µm
Chosen irradiation fluences in 1e14neq/cm²
A. Dierlamm
Institut für Experimentelle Kernphysik
8 17.09.2012 VERTEX 2012, Jeju, Korea
Caveat
The campaign is not completed yet! The highest irradiation and an additional set of GeV proton irradiations was performed, but not all samples are characterized yet
Final analyses and simulations ongoing
There are plenty of measurements on a multitude of structures, which cannot be summarized in the given time frame
I concentrate on measurements obtained from strip sensors mainly done at KIT
In addition, we perform beam tests and the analysis will be presented at RESMDD12 in Florence
investigate dedicated test-structures designed for fast evaluation of process quality of large-scale productions (will also be presented at RESMDD12)
investigate trapping effects and the electric fields with TCT and edge-TCT
perform simulation studies to understand and predict the device performance
investigate various designs of pixel and short strip sensors for inner tracker regions
64 strips,
80µm pitch,
2.6cm long
256 strips,
80µm pitch,
3.3cm long
A. Dierlamm
Institut für Experimentelle Kernphysik
9 17.09.2012 VERTEX 2012, Jeju, Korea
0.0 5.0x1014
1.0x1015
1.5x1015
0.00
0.02
0.04
0.06
0.08
0.10
0.12
FZ320N
FZ320P
FZ200N
FZ200P
MCZ200N
MCZ200P
Expectation
Sca
led
Vo
lum
e C
urr
en
t a
t R
T (
A/c
m3)
Fluence(neq
/cm2)
Diodes @ 1.2xVfd and -20°C
Leakage Currents - Diodes
Volume generated leakage current
of diodes well within expectations
1011 1012 1013 1014 1015
eq [cm-2]
10-6
10-5
10-4
10-3
10-2
10-1
I
/ V
[
A/c
m3]
n-type FZ - 7 to 25 Kcm
n-type FZ - 7 Kcm
n-type FZ - 4 Kcm
n-type FZ - 3 Kcm
n-type FZ - 780 cm
n-type FZ - 410 cm
n-type FZ - 130 cm
n-type FZ - 110 cm
n-type CZ - 140 cm
p-type EPI - 2 and 4 Kcm
p-type EPI - 380 cm
[M.Moll PhD Thesis][M.Moll PhD Thesis]
protons
neutrons
T scaling: ~ T²exp(-1.21eV/(2kBT)
A. Dierlamm
Institut für Experimentelle Kernphysik
10 17.09.2012 VERTEX 2012, Jeju, Korea
Leakage Currents – Strip Sensors
0 200 400 600 800 1000
0
100µ
200µ
300µ
Cu
rre
nt (A
)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
Strip Sensors @ -20°C
F=1e15neq
/cm² (protons)
IV curve does not show a nice plateau after Vfd
Chose 600V for comparison, which is the max. voltage of current CMS
Tracker PS
Leakage currents tend to be higher for 200µm sensors (up to ~40%)
Absolute temperature measurement is difficult and leads to large errors
protons
neutrons
mixed
A. Dierlamm
Institut für Experimentelle Kernphysik
11 17.09.2012 VERTEX 2012, Jeju, Korea
Strip Sensors – CV and Full Depletion Voltages
Vfd vs. F increases faster for thick
and for p-type sensors
Points at 7e14neq/cm² are taken
after mixed irradiation (3e14neq/cm²
protons and 4e14neq/cm² neutrons
plus additional annealing of
~19min@60°C)
We see a kind of saturation for
F>5e14neq/cm²
0 100 200 300 400 500
0.0
5.0x1018
1.0x1019
1.5x1019
2.0x1019
F=0neq
/cm²
T=+20°C
f=1000Hz
1/C
^2
(F
-2)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
0 200 400 600 800 1000
0.0
5.0x1018
1.0x1019
1.5x1019
2.0x1019
1/C
^2
(F
-2)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
F=5e14neq
/cm² (n)
T=-20°C
f=1000Hz
0 200 400 600 800 1000
0.0
5.0x1018
1.0x1019
1.5x1019
2.0x1019
F=10e14neq
/cm² (p)
T=-20°C
f=1000Hz
1/C
^2
(F
-2)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
0 1 2 3 4 5 6 7 8 9 100
100
200
300
400
500
600
700
800
900
1200
Fu
ll D
ep
letio
n V
olta
ge
(V
)
Fluence (1e14neq
/cm²)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
above 1000V
protons
neutrons
mixed&annealing
A. Dierlamm
Institut für Experimentelle Kernphysik
12 17.09.2012 VERTEX 2012, Jeju, Korea
Neff Comparison – Strip Sensors vs. Diodes
Although the determination of full depletion voltage after irradiation is not very
accurate, the results from strip sensors and diodes of same materials show good
agreement.
0 1 2 3 4 5 6 7 8 9 100.0
5.0x1012
1.0x1013
1.5x1013
2.0x1013
2.5x1013
3.0x1013
|Ne
ff|(
cm
-3)
Fluence (1e14neq
/cm²)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
0 1 2 3 4 5 6 7 8 9 100.0
5.0x1012
1.0x1013
1.5x1013
2.0x1013
2.5x1013
3.0x1013
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
|Ne
ff|(
cm
-3)
Fluence (1e14neq
/cm²)
protons
neutrons
mixed&annealing
Strip Sensors Diodes
A. Dierlamm
Institut für Experimentelle Kernphysik
13 17.09.2012 VERTEX 2012, Jeju, Korea
Strip Parameters vs. Fluence – I
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1625.0p
26.0p
27.0p
28.0p
29.0p
30.0p
protons
neutrons
mixed
Co
up
ling
Ca
pa
cita
nce
(F
/cm
)
Fluence (1e14neq
/cm²)
FZ320N FZ200N MCZ200N
FZ320P FZ200P MCZ200P
FZ320Y FZ200Y MCZ200Y
Vbias
= 600V
T = -20°C
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
600.0k
800.0k
1.0M
1.2M
1.4M
1.6M
1.8M
2.0M
2.2M
2.4M
2.6M
2.8M
3.0M
3.2M
3.4M
Vbias
= 600V
T = -20°C
Bia
s r
esis
tan
ce
(
)
Fluence (1e14neq
/cm²)
FZ320N FZ200N MCZ200N
FZ320P FZ200P MCZ200P
FZ320Y FZ200Y MCZ200Y
protons
neutrons
mixed
Hardly any change of coupling capacitance
(~4% variations)
Decrease of inter-strip resistance
p-spray isolation (FZ320Y) still shows
about 50Mcm at 3.8e15neq/cm² !
saturation value?
Increase of bias resistance by 15-25%
independent of particle type (p/n)
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 36 37 38 39
100k
1M
10M
100M
1G
10G
100G
1T
10T
Vbias
= 600V
T = -20°C
FZ320Y Badd
Inte
r-str
ip R
esis
tan
ce
(
cm
)
Fluence (1e14neq
/cm²)
FZ320N FZ200N MCZ200N
FZ320P FZ200P MCZ200P
FZ320Y FZ200Y MCZ200Y
protons
neutrons
mixed
A. Dierlamm
Institut für Experimentelle Kernphysik
14 17.09.2012 VERTEX 2012, Jeju, Korea
Strip Parameters vs. Fluence – II
Minor changes in inter-strip capacitance
Back capacitance quite different for p- and n-type due to difference in CV curve
results in ~7.5% higher strip capacitance for p-type sensors at F≥1e15neq/cm² at moderate bias voltage (600V)
Strip capacitance increases about 5% after 3e14neq/cm² and stays at that level
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 36 37 38 39
380f
400f
420f
440f
460f
480f
500f
520f
Vbias
= 600V
T = -20°C
protons
neutrons
mixed
FZ320Y Badd
Inte
r-str
ip C
ap
acita
nce
(F
/cm
)
Fluence (1e14neq
/cm²)
FZ320N FZ200N MCZ200N
FZ320P FZ200P MCZ200P
FZ320Y FZ200Y MCZ200Y
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
150f
200f
250f
300f
350f
400f
450f
500f
550fprotons
neutrons
mixed
Vbias
= 600V
T = -20°C
Str
ip B
ack C
ap
acita
nce
(F
/cm
)
Fluence (1e14neq
/cm²)
FZ320N FZ200N
FZ320P FZ200P
FZ320Y FZ200Y
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 161.10p
1.15p
1.20p
1.25p
1.30p
1.35p
1.40p
1.45p
1.50p
1.55p
1.60p
protons
neutrons
mixed
Vbias
= 600V (900V)
T = -20°C
To
tal S
trip
Ca
pa
cita
nce
(F
/cm
)
Fluence (1e14neq
/cm²)
FZ320N FZ200N
FZ320P FZ200P
FZ320Y FZ200Y
A. Dierlamm
Institut für Experimentelle Kernphysik
15 17.09.2012 VERTEX 2012, Jeju, Korea
Label 1-120 1-240 1-80 1-70 2-120 2-240 2-80 2-70 3-120 3-240 3-80 3-70
Region 1 2 3 4 5 6 7 8 9 10 11 12
Pitch 120 240 80 70 120 240 80 70 120 240 80 70
Width 16(+1) 34(+1) 10(+1) 8.5(+1) 28(+1) 58(+1) 18(+1) 15.5(+1) 40(+1) 82(+1) 26(+1) 22.5(+1)
Width Al 29(-5) 47(-5) 23(-5) 21.5(-5) 41(-5) 71(-5) 31(-5) 28.5(-5) 53(-5) 95(-5) 39(-5) 35.5(-5)
w/p 0.133
(0.142)
0.142
(0.146)
0.125
(0.138)
0.121
(0.136)
0.233
(0.242)
0.242
(0.246)
0.225
(0.238)
0.221
(0.236)
0.333
(0.342)
0.342
(0.346)
0.325
(0.338)
0.321
(0.336)
Multi-geometry Silicon Strip Detector (MSSD)
Measure strip capacitance for various
layouts
Validation of results from 2000 and
extension of measurement range for
thinner sensors
?
1 12
NIM A 466 (2001) 300-307
A. Dierlamm
Institut für Experimentelle Kernphysik
16 17.09.2012 VERTEX 2012, Jeju, Korea
MSSD – Strip Capacitances at 200µm
Strip capacitance stays constant for given w/p ratio also for 200µm
Large pitch of 240µm:
increased strip
capacitance due to high Cbck
early break down
not considered as
option for CMS Tracker
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.00.0
0.5
1.0
1.5
2.0
p=240µm
p=120µmp=80µm
C_int (pF/cm) C_bck (pF/cm) C_strip (pF/cm)
w/p=0.13 w/p=0.23 w/p=0.33
FZ200N FZ200P FZ200Y
Ca
pa
cita
nce
(p
F/c
m)
p/(d+pf(w/p))
p=70µm
A. Dierlamm
Institut für Experimentelle Kernphysik
17 17.09.2012 VERTEX 2012, Jeju, Korea
MSSD – Cint Ramp Simulations
Mostly excellent agreement with
measurements on all geometries
Simulations performed with Silvaco ATLAS
and confirmed with Synopsys Sentaurus
p=120µm p=240µm
p=80µm p=70µm
p=120µm p=240µm
p=80µm p=70µm
p=120µm p=240µm
p=80µm p=70µm
A. Dierlamm
Institut für Experimentelle Kernphysik
18 17.09.2012 VERTEX 2012, Jeju, Korea
MSSD – Strip Capacitance vs. Fluence
Almost no change of strip capacitances
of all geometry variations as observed
for standard mini strip sensors (close to
geometry 2-80) for high bias voltage
0 5 10 151.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
To
tal S
trip
Ca
pa
cita
nce
(p
F/c
m)
Fluence (1e14neq
/cm²)
1-120
1-240
1-80
1-70
2-120
2-240
2-80
2-70
3-120
3-240
3-80
3-70
FZ200N @ 500V
0 5 10 151.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.3
2.4
2.5
To
tal S
trip
Ca
pa
cita
nce
(p
F/c
m)
Fluence (1e14neq
/cm²)
1-120
1-240
1-80
1-70
2-120
2-240
2-80
2-70
3-120
3-240
3-80
3-70
FZ200P @ 500V
0 5 10 151.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
To
tal S
trip
Ca
pa
cita
nce
(p
F/c
m)
Fluence (1e14neq
/cm²)
1-120
1-240
1-80
1-70
2-120
2-240
2-80
2-70
3-120
3-240
3-80
3-70
FZ200P @ 800V
A. Dierlamm
Institut für Experimentelle Kernphysik
19 17.09.2012 VERTEX 2012, Jeju, Korea
Charge Collection – Intro
Measurement done with Sr90 source and Beetle
read-out chip with ~20ns shaping time
(ALiBaVa system) on standard mini sensors
Cluster charge with 5σ seed and 2σ neighbor cut
Calibration work is in progress
(chips individually sensitive to T, Cstrip)
We do voltage ramps up to 1000V for
each material and fluence, and at several
annealing steps after mixed irradiation
0 200 400 600 800 1000
4000
6000
8000
10000
12000
14000
16000
18000
20000
22000
24000
26000
Sig
na
l (e
-)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
F=0eq
/cm²
T=+20°C
Sr90 source
0 200 400 600 800 1000
4000
6000
8000
10000
12000
14000
16000
18000
20000
22000
24000
26000
Sig
na
l (e
-)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
F=3e14neq
/cm² (p)
T=-20°C
Sr90 source
0 200 400 600 800 1000
4000
6000
8000
10000
12000
14000
16000
18000
20000
22000
24000
26000
Sig
na
l (e
-)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
F=4e14neq
/cm² (n)
T=-20°C
Sr90 source
0 200 400 600 800 1000
4000
6000
8000
10000
12000
14000
16000
18000
20000
22000
24000
26000
Sig
na
l (e
-)Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
F=1e15neq
/cm² (p)
T=-20°C
Sr90 source
FZ320N
V = 500V
F = 1e15neq/cm²
FZ320N
V = 500V
F = 0neq/cm²
A. Dierlamm
Institut für Experimentelle Kernphysik
20 17.09.2012 VERTEX 2012, Jeju, Korea
Charge Collection – Summary
F≤7e14neq/cm² (Tracker radius of ≥40cm)
Thicker material gives more charge
No dominance of p- vs. n-type visible
At 1e15neq/cm²
FZ320N collects least charge in the voltage range of 400V – 600V, but catches up ≥ 700V
FZ materials shows increasing charge from 600V to 900V, MCz does not
collected charge is above 10’000e- for all materials at 600V (current PS limit)
At 1.5e15neq/cm² (Tracker radius of ~20cm)
Only one point at the moment
FZ320P shows signal below 10’000e- at 600V!
0 200 400 600 800 10004000
6000
8000
10000
12000
14000
16000
18000
20000
Sig
na
l (e
-)
Voltage (V)
FZ320N
FZ320P
FZ200N
FZ200P
M200N
M200P
F=1e15neq
/cm² (p)
T=-20°C
Sr90 source
0 2 4 6 8 10 12 14 165000
10000
15000
20000
25000
30000
FZ320N 600V FZ320N 900V
FZ320P 600V FZ320P 900V
FZ200N 600V FZ200N 900V
FZ200P 600V FZ200P 900V
M200N 600V M200N 900V
M200P 600V M200P 900V
co
rr. S
ign
al (e
-)
Fluence (1e14neq
/cm²)
protons
neutrons
mixed
A. Dierlamm
Institut für Experimentelle Kernphysik
21 17.09.2012 VERTEX 2012, Jeju, Korea
240 480 720 1000 100008000
10000
12000
14000
16000
18000
20000
co
rr. S
ign
al (e
)
eq. annealing time at RT (h)
FZ320N 600V
FZ320P 600V
FZ320N 900V
FZ320P 900V
10.0 20.0 30.0 41.7 416.7
eq. annealing time at RT (days)
Charge Collection – Annealing
About 10 days annealing is beneficial
1-2 months at RT during maintenance/accidents can be tolerated
Longer annealing reduces signal by almost 50% in one year at RT
Mixed irradiation (~40cm):
3e14neq/cm² (p) & 4e14neq/cm² (n)
A. Dierlamm
Institut für Experimentelle Kernphysik
22 17.09.2012 VERTEX 2012, Jeju, Korea
Cluster width vs. Fluence and Bias Voltage
Cluster widths for perpendicular tracks and seed/neighbors cut of 5/2 s.
The cluster width profiles differ significantly for n- and p-type sensors.
This is important for performance simulations.
How does it look like for binary read-out?
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
Clu
ste
r w
idth
Voltage (V)
FZ320N
Cluster definition: 5/2
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0 Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
Cluster definition: 5/2
clu
ste
r w
idth
Voltage (V)
FZ200P
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
clu
ste
r w
idth
Voltage (V)
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
FZ200N
Cluster definition: 5/2
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
Clu
ste
r w
idth
Voltage (V)
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
FZ320P
Cluster definition: 5/2
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
clu
ste
r w
idth
Voltage (V)
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
M200P
Cluster definition: 5/2
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
clu
ste
r w
idth
Voltage (V)
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
M200N
Cluster definition: 5/2
A. Dierlamm
Institut für Experimentelle Kernphysik
23 17.09.2012 VERTEX 2012, Jeju, Korea
Binary interpretation
Cluster width is much smaller in binary mode (1.1-1.4 x pitch(80µm))
Cluster width approaches similar values for p- and n-type
6240e- threshold might miss some clusters already at 5e14neq/cm² and perpendicular tracks; CBC could be optimized for lower thresholds since noise is expected to be ~1000e- for 5cm long strips; to be seen…
Larger inclination means larger spread of charge, therefore even more clusters lost (under investigation with cosmic telescope…)
2000 4000 6000 8000 10000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200N, 600V, F=5e14neq
/cm²
2000 4000 6000 8000 10000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200P, 600V, F=5e14neq
/cm²
<95% clusters
found
<95% clusters
found
A. Dierlamm
Institut für Experimentelle Kernphysik
24 17.09.2012 VERTEX 2012, Jeju, Korea
Lorentz Shifts – Magnetic field, Bias Voltage
Shift increases almost linearly with magnetic field; small deviations at B>6T
Holes show about half the shift of electrons due to smaller mobility and rH
Shift increases up to full depletion voltage
Shift reduces for high bias voltage and approaches a saturation value
A. Dierlamm
Institut für Experimentelle Kernphysik
25 17.09.2012 VERTEX 2012, Jeju, Korea
Lorentz Shifts – Irradiation, Annealing
Shift for holes is initially smaller than for electrons and seems to have a maximum around 1e15neq/cm²
there is almost no annealing effect with the tendency to reduce the shift
Shift for electrons is larger, but falls continuously with F
annealing makes the clusters move by ~10µm in 300µm sensors at 4T
long-term annealing reduces the shift further
n-type:
holes
p-type:
electrons
A. Dierlamm
Institut für Experimentelle Kernphysik
26 17.09.2012 VERTEX 2012, Jeju, Korea
FOSTER – Intro
New design: FOur-fold segmented STrip sensor
with Edge Readout
increase granularity
keep sensor size of ~10cm x 10cm
allow correlation of two sensor planes on
hybrid at the edge
pT module concept,
M. Raymond, TWEPP2008
A. Dierlamm
Institut für Experimentelle Kernphysik
27 17.09.2012 VERTEX 2012, Jeju, Korea
FOSTER – Laser scan
The initial implementation
showed unexpected
behavior since many hits
in the near region would
have been wrongly
associated to the far
region
There are ~30% wrongly
assigned clusters when
using a Sr90 source in
the near region
This was seen for p- and
n-type sensors
alu
min
ium
alu
min
ium
alu
min
ium
Far region Near region
alu
min
ium
alu
min
ium
A. Dierlamm
Institut für Experimentelle Kernphysik
28 17.09.2012 VERTEX 2012, Jeju, Korea
FOSTER – Simulation
Device simulations showed that a common p-stop layer below the read-out strip of an n-in-p sensor would shield it from induced charge and reduce the wrong signals significantly
A structure with this layout modification has been produced at ITE Warsaw and first measurements show indications that the concept works (these measurements are subject to a separate publication)
0 10 20 30 40 50 60 70 80 90 100
0,00E+000
1,00E-015
2,00E-015
3,00E-015
4,00E-015
5,00E-015
Nimp
=1e16cm-3
Qox=1e11cm-2
Ch
arg
e [
C]
Position [µm]
Individ. p-stop
Left strip
RO strip
Right strip
Common p-stop
Left strip
RO strip
Right strip
A. Dierlamm
Institut für Experimentelle Kernphysik
29 17.09.2012 VERTEX 2012, Jeju, Korea
Not So Nice Observations
Very few devices showed sudden rise of leakage current, which could be cured
by storage in dry atmosphere for few days
Similarly on very few devices we observed shifts in break down voltages
Few 200µm thin MCz sensors broke easily by handling
assembly of modules to be exercised with 200µm dummy wafers…
Characteristics of MCz material showed dependence on proton irrad. energy
Therefore we performed an additional irradiation campaign with GeV protons on
diodes and mini strip sensors of FZ and MCz;
the samples will be delivered to the labs soon…
MCz200/280N diodes irrad. with ~3e14neq/cm²;
Udep from CV
A. Dierlamm
Institut für Experimentelle Kernphysik
30 17.09.2012 VERTEX 2012, Jeju, Korea
Outlook
Within the CMS Tracker Sensor Working Group we are conducting a
comparative measurement campaign to identify suitable strip sensors
for the next CMS Tracker
We are about to complete the necessary irradiation steps and
measurements to be able to provide information about performance
and features of the various options
Together with the CMS Tracker Simulation Group we will concentrate
on optimizing the tracker performance taking into account the CMS
read-out chip, L1 trigger options and material budget (not to forget
costs and handling)
The CMS Tracker Upgrade group will decide on the silicon material by
beginning of 2013
A. Dierlamm
Institut für Experimentelle Kernphysik
31 17.09.2012 VERTEX 2012, Jeju, Korea
Thank you for your attention and thanks to the participating institutes
for their contributions
Irradiations funded by:
HPK Campaign
A. Dierlamm
Institut für Experimentelle Kernphysik
32 17.09.2012 VERTEX 2012, Jeju, Korea
BACKUP
A. Dierlamm
Institut für Experimentelle Kernphysik
33 17.09.2012 VERTEX 2012, Jeju, Korea
Deep diffusion profiles
FZ320P
FZ200P deep diff.
FZ120P deep diff.
~
A. Dierlamm
Institut für Experimentelle Kernphysik
34 17.09.2012 VERTEX 2012, Jeju, Korea
Karlsruhe Proton Cyclotron
E ~ 23MeV
Inominal = 1.7µA
T < 0°C
Rbeam ~ 3mm
Beam line with target box Control room
Target box Autoradiography image
of irradiation area Typical beam profile
A. Dierlamm
Institut für Experimentelle Kernphysik
35 17.09.2012 VERTEX 2012, Jeju, Korea
Ljubljana Reactor – I
A. Dierlamm
Institut für Experimentelle Kernphysik
36 17.09.2012 VERTEX 2012, Jeju, Korea
Ljubljana Reactor – II
A. Dierlamm
Institut für Experimentelle Kernphysik
37 17.09.2012 VERTEX 2012, Jeju, Korea
Charge Collection
0 200 400 600 800 1000
5000
10000
15000
20000
FZ200P
Sig
na
l (e
-)
Voltage (V)
Fluence in
1e14neq
/cm²
F=0
F=3
F=4
F=5
F=10
F=0
0 200 400 600 800 1000
5000
10000
15000
20000
FZ200N
Sig
na
l (e
-)
Voltage (V)
Fluence in
1e14neq
/cm²
F=0
F=3
F=4
F=5
F=7
F=10
0 200 400 600 800 1000
5000
10000
15000
20000
25000
30000
FZ320P
Sig
na
l (e
-)
Voltage (V)
Fluence in
1e14neq
/cm²
F=0
F=3
F=4
F=5
F=7
F=10
0 200 400 600 800 1000
5000
10000
15000
20000
25000
30000
FZ320N
Sig
na
l (e
-)
Voltage (V)
Fluence in
1e14neq
/cm²
F=0
F=3
F=4
F=5
F=7
F=10
A. Dierlamm
Institut für Experimentelle Kernphysik
38 17.09.2012 VERTEX 2012, Jeju, Korea
Eta functions for FZ200P and FZ200N @ 500V
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0 Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
Cluster definition: 5/2
clu
ste
r w
idth
Voltage (V)
FZ200P
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
clu
ste
r w
idth
Voltage (V)
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
FZ200N
Cluster definition: 5/2
FZ200P, 5e14, 500V FZ200N, 5e14, 500V
A. Dierlamm
Institut für Experimentelle Kernphysik
39 17.09.2012 VERTEX 2012, Jeju, Korea
Eta functions for FZ200P and FZ200N @ 600V
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0 Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
Cluster definition: 5/2
clu
ste
r w
idth
Voltage (V)
FZ200P
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
clu
ste
r w
idth
Voltage (V)
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
FZ200N
Cluster definition: 5/2
FZ200N, 5e14, 600V FZ200P, 5e14, 600V
A. Dierlamm
Institut für Experimentelle Kernphysik
40 17.09.2012 VERTEX 2012, Jeju, Korea
Binary interpretation – n-type
Cluster width
much smaller in
binary mode
Stays within 1.1-
1.4 in efficient
threshold range
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
clu
ste
r w
idth
Voltage (V)
Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
FZ200N
Cluster definition: 5/2
5000 10000 15000 20000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200N, 400V, F=5e14neq
/cm²
5000 10000 15000 20000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200N, 600V, F=5e14neq
/cm²
5000 10000 15000 20000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200N, 900V, F=5e14neq
/cm²
<95% clusters found
A. Dierlamm
Institut für Experimentelle Kernphysik
41 17.09.2012 VERTEX 2012, Jeju, Korea
Binary interpretation – p-type
Similar cluster
width as in n-
type (1.1-1.3)
0 200 400 600 800 10000.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0 Fluence in 1e14neq
/cm²
F=0 F=4 F=7
F=3 F=5 F=10
Cluster definition: 5/2
clu
ste
r w
idth
Voltage (V)
FZ200P
5000 10000 15000 20000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200P, 400V, F=5e14neq
/cm²
5000 10000 15000 20000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200P, 600V, F=5e14neq
/cm²
5000 10000 15000 20000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Threshold (e-)
Fraction 1-strip clusters
Fraction 2-strip clusters
Fraction 3-strip clusters
Fraction >3-strip clusters
avg. width
CIE
FZ200P, 900V, F=5e14neq
/cm²
<95% clusters found
A. Dierlamm
Institut für Experimentelle Kernphysik
42 17.09.2012 VERTEX 2012, Jeju, Korea
Calibration of Beetle chips
1.15 1.20 1.25 1.30 1.35
60
70
80
90
100
112130
30
31
4050
51
5121
31
31
40
51
12
0N
20
0P
20
0N
32
0N
S/D
(e
/µm
)
Cstrip (pF/cm)
n-type
p-type3
20
P
A. Dierlamm
Institut für Experimentelle Kernphysik
43 17.09.2012 VERTEX 2012, Jeju, Korea
Scaling of Annealing Time
10m
in@
60°C
20m
in@
60°C
20m
in@
60°C
40m
in@
60°C
76m
in@
60°C
15m
in@
80°C
30m
in@
80°C
60m
in@
80°C
0.1
1
10
100
1000
10000
100000
50
129204
358
700
1970
4978
10085
10
30
50
90
166
346
766
1547
0.9
2.7
4.7
8.7
15.9
30.9
60.9
120.9
5.32
4.79
4.47
4.05
3.59
3.16
2.88
2.66
E
qu
iva
len
t cu
rre
nt a
nn
ea
ling
tim
e
21°C in h
60°C in min
80°C in min
1
2
3
4
5
6
7
alp
ha
(1
e-1
7A
/cm
)
A. Dierlamm
Institut für Experimentelle Kernphysik
44 17.09.2012 VERTEX 2012, Jeju, Korea
FOSTER – Source measurements on FZ320N
ADC
Source above near region:
seed is near-strip
ADC
Source above near region:
seed is far-strip
ADC
Source above far region:
seed is near-strip
ADC
Source above far region:
seed is far-strip
Recommended