0Summary of Continuous Acquisition Pixel Detector Collaboration Activities
ILC VTX Issues being Addressed
• Sensor Design• Optimization studies for thin pixel device for Super-B upgrade• Study of radiation hardness/max storage density
• High Performance/IR Design• Experience with low momentum track finding under high occupancy
conditions• Detector-Machine Interface Background Monitoring and Mitigation
• Low Occupancy• High frame rate architectures• Deeper storage outside acceptance
• EMI Mitigation• RF isolation experience (UHF radio neutrino work)• Robustness against pickup
1Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Relationship to Existing Efforts
• Hear from many this week• Various pieces of the puzzle, far from a complete solution• Timescale not consistent with locking into specific processes• Funding Limitations (collaboration)
• Technology choices (concerns)• Epitaxial structures• SOI initiatives (triple well, 3D)
• To date no thin Si pixel vertex detector fielded• Learn from experience designing/operating• 2012 Belle/KEKB upgrade – possibly also at Frascati• Will lead to an improved detector
2Summary of Continuous Acquisition Pixel Detector Collaboration Activities
In both cases, want to re-use as much as possible
3Summary of Continuous Acquisition Pixel Detector Collaboration Activities
SVT Layer 0
• Depends critically on background level– Striplet solution (baseline)
• Basically already available technology but more sensitive to background. OK for 1MHz/cm2
• Some margin to improve background sensitivity
– Monolithic Active Pixel Solution solution (upgrade)
• R&D is still ongoing but giving a big safety margin in terms of performance and occupancy
• Cooling and mechanical issues need work
• Active R&D program in place
V
U1.35 cm
7.7 cm
Basically the same condition as for Super Belle
Continuous Acquisition Pixel Detector Collaboration
G. Varner1, H. Aihara5, Y. Arai3, M. Barbero1, A. Bozek4, T. Browder1, M. Cooney1, P. Chang7, E. Martin1, M. Hazumi3, H. Hoedlmoser1, J. Kennedy1,
S. Olsen1, Z. Natkaniec4, H. Palka4, M. Rosen1, L. Ruckman1, H. Sahoo1,S. Stanič6, G. Taylor2, K. Trabelsi3, T. Tsuboyama3, K. Uchida1 and P. Yuan7
1University of Hawaii, 2 University of Melbourne,3 High Energy Accelerator Research Organization (KEK),
4 H. Niewondiczanski Institute of Nuclear Physics,5 University of Tokyo, 6 Nova Gorica Polytechnic
7 National Taiwan University
5Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Team Experience
6Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Critical R&D Issues (circa 2004)
1. Readout Speed
2. Radiation Hardness
3. Thin Detector
4. Full-sized detector (mech/power)
7Summary of Continuous Acquisition Pixel Detector Collaboration Activities
VDD VDD
GND
M1
M2
M3
Reset
ColumnSelect
Row BusOutput
CollectionElectrode
Cont. Acq. Pixels (CAP) 1 Prototype
Column Ctrl Logic
1.8mm 132col*48row ~6 Kpixels
CAP1: simple 3-transistor cell
Pixel size:
22.5 μm x 22.5 μm
CAPs sample tested: all detectors (>15) function.
Source follower buffering of collected charge
Restores potential to collection electrode
Reset
Vdd Vdd
Collection Electrode
Gnd
M1
M2
M3Row Bus Output
Column Select
charge collection in cluster
405060708090
100110
1 2 3 4 5 6 7 8 9
# pixels in cluster
% c
harg
e / 3
X3
arra
y
Det1Det2Det3Det4
NIM A541:166-171 (2005)
8Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP2 – Pipelined operation
Col8
VAS
VddPixel Reset
Sense
Output Bus
REFbias
Col2
Col1Sample1
Sample8
Sample2
8 deep mini-pipeline in each cell
Pixel size 22.5 μm x 22.5 μm
3-transistor cell132x48=6336 channels 50688 samples
TSMC 0.35μm
132 x 48
10μs frame acquisition speed achieved!
9Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP3: Full-size Detector Test/Lessons learned
Laser scan bench
Laser spot (backside illumination)
noise
10Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Critical C(M)APS R&D Scorecard
1. Readout Speed
2. Radiation Hardness
3. Thin Detector
4. Full-sized detector
100kHz frame rate, 10kHz L2 accept
>= 20MRad
<= 50μm, layer
Span acceptance (reticle limit)
CAP3 too slow, SNR concerns
Leakage current OK (CAP2) for short integration time
50μm LBL test bench, thinning at APTEK (same SNR)
CAP3 large acceptance biasing/uniformity
11Summary of Continuous Acquisition Pixel Detector Collaboration Activities
SNR: Summary of MAPS Efforts
Comparison of Signal-to-Noise
0
5
10
15
20
25
30
CAP1
CAP2
CAP3APS
_LBL
MIMOSA I
MIMOSA II
p13u
mAmpsNwell
13um
MIMOSA8
Apsel
1RAL_
HEPAPS
SN
R
12Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Noise (ENC): Summary of MAPS
Noise Comparison
0
10
20
30
40
50
60
1000 10000 100000 1000000 10000000
Total Number of Storage Cells
Eq
uiv
. N
ois
e C
har
ge
[e-]
CAP1CAP2CAP3MIMOSA2RAL_HEPAPS
Unfortunately signal sizeFixed and small
13Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Buffered LABRADOR (BLAB1) ASIC
• 64k storage samples
• Wilkinson conversion (digital out)
• Fast (sub-uW power)
3mm x 2.8mm, TSMC 0.25um
1.4mV
Low Noise Readout: MAPS applications
14Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP4: 3 architectures in AMS 0.35um Opto
CAP4 revision
• Four different architectures• Wilkinson Ramp transfer
encoding• Mostly NMOS space-time
encoding scheme (modest charge collection loss)
• CMOS space-time encoding scheme (large collection efficiency loss)
• Evaluations• Speed • Uniformity• Evaluate space-time technique
• Apply lessons learned
15Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Hit resolution vs. SNR MC
Signal MC:
1) Generate random impact parameter
2) Landau fluctuation of signal
3) Charge diffusion (thermal)
4) Add noise (16e-/30e- system)
5) CoG of hit calculation
Note binary limit: 22.5µm/sqrt(12) ~6.5µm
Good hit resolution even at low SNR
Canonical 4 µm : 4µm*sqrt(12) ~13.85µm
16Summary of Continuous Acquisition Pixel Detector Collaboration Activities
• Binary Readout (11.25um/SQRT(12) ~ 3.25um)
• 100ns sample steps – values shifted out left/right
• Use temporal coincidence and match with fixed latency to reconstruct position and reject out of time hits
Space-Time Encoding
Per row:
External Pipeline (length set by trigger latency):
At trigger latency time, A&B = 1 @ X[j]
B
A
X[j]
A
B
17Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP4 Results – laser scan
• Design issues• Transparent latch
(chattering pixels)• Missing transistor
• CAP6 addresses
18Summary of Continuous Acquisition Pixel Detector Collaboration Activities
OKI 0.15um SOI
• Best of both worlds• High resistivity, fully
depleted detector (large signal)
• Excellent deep submicron CMOS
• Wafer bonding• No bump bonding
interconnects • Very low collection
electrode capacitance
• Rad hardness• SOI known to be rad-
hard
19Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP5: 2nd iteration in OKI 0.15um SOI
first revision
second revision • First submission• Debugged process for
non-Japanese• Problems with backside
bias/backgate effects
• Second submission• Learn from first lessons • Study process spread• Evaluate space-time
correlation
VCQV
mVvCkTv
Electrodenoise
noise
151.0
822.0_
=Δ
=Δ
=
=
20Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP5: 2nd iteration in OKI 0.15um SOIMPW run
• First round• Promise of better S,
same N better SNR• Many other groups
(FNAL/BNL & LBL) subsequently join
• Second round• 4x larger die • Bias effects (FD?)• Other lessons
• Will apply lessons learned • Next SOI run (0.2um)
in January •108 x 34 pixels total structure (28.7 μm by 32.5 μm)•6 row testing structures introduced•Use of CMOS circuits for all structures
21Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Pixel Detector Study Activities
• CAP1/2 [MAPS technology] Studies• Characterization of CAP1 in test beam [NIM A541 (2005) 166]
• Study of radiation hardness/storage [IEEE Trans.Nucl.Sci.52 (2005) 1187]
• Storage density/max. pipeline depth studies
• CAP3 “full size” Detector [NIM A565 (2006) 126]• Development of laser scan system for systematic studies• Systematic scan and study of transfer rate and signal uniformity• Non-uniformity and transfer limitations observed
• CAP4 AMS 0.35um Opto [NIM A568 (2006) 181]• Study of new analog storage/readout CAP6 submitted
• CAP5 SOI prototype – second run received, studying• Study of 0.15um OKI process [SLAC-PUB-12079]
• Fully depleted, time-space correlation storage study CAP7
22Summary of Continuous Acquisition Pixel Detector Collaboration Activities
• Worldwide Effort to field thin Si pixel sensor:– Targets: STAR, Super-B and ILC
– No experiment has yet deployed, 2 roadblocks:• SNR: SOI/better readout looks promising to increase
• Full-size detector: on which technology to gamble?
• Plans:– CAP4 (binary, Wilkinson MAPS) techniques CAP6
– CAP5 (binary) SOI in test CAP7
– Hard to provide specific schedule due to funding uncertainties
– OKI SOI submission in January real prototype
– MAPS thinning proven, Oki SOI to be shown
Status Summary
23Summary of Continuous Acquisition Pixel Detector Collaboration Activities
High Luminosity Lepton Colliders
24Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP4: Binary readout
pixel matrix: 17 rows 118 columnspixel size: 25.5 x 30.9 μm2
pixel schematics:
25Summary of Continuous Acquisition Pixel Detector Collaboration Activities
CAP4: Binary readout
re-arranged data output:left out signal : 000100000000000000000…right out signal : 000000000000000000100…
hit reconstruction:calculation of hit position and time from the timing of the left out and right out signals
multiplexing:6 rows to one pad
26Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Test Beam/KEK π2-area
B2 / ACQ monitoringempty tables (1st day)
CAP targets ! / “do not touch” sign
4 F2s / Pixel Sensor/ 1st very rough alignment
27Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Hits! alignment proof
28Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Resolution: GEANT Expectation
3μm input resolution
250um Si1mm plastic
1mm Alumina substrate
3.4 cm3.6 cm4.6 cm
29Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Irradiation: leakage currents
IEEE Trans. Nucl. Sc. 48, 1796-1806,2001
Leakage Current [fA]
# of
pix
els
Before irrad.
200 Krad
30Summary of Continuous Acquisition Pixel Detector Collaboration Activities
Thin Mechanics