IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP
Applications of Silicon Detectors
Hartmut F.-W. SadrozinskiSanta Cruz Institute for Particle Physics (SCIPP)
Principle of OperationsThe Rise of Silicon DetectorsApplications
Charged Particle TrackingPhoton Detection
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Area of Application of Silicon Detectors
Gravitation Electro-magnetic Weak Strong Interaction
Astrophysics:Imaging, Tracking
Medicine:Imaging
X-talography:Imaging
Particle Physics:Tracking
Nuclear PhysicsX-Spectroscopy
R&D and Applicationsextends from Quarks (1028m).
Silicon Detectors are used forScience at every scale.
The choice of detector depends on the energy, time structure and strength of the signal
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Principle of Silicon Strip Detectors
25-200 µm
300-400 µm
Alat ~ 100V
n+ implant
Al SiO2
p+ implantat ground
Depletion region. Charged particletraversing region produces ~80electron/hole pairs per micron.
Readout electronics(S/N typically > 20)
holes
Reverse Bias of junction: thermal current generationScale : Band gap 1.12eV vs. kT = 1/40eVCooling needed only in ultra-low noise applications.Wafer thickness 300um = 24k e-h pairs = 0.3%RLDepletion Voltage ~ thickness2 Ladders
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Evolution of Silicon Detectors
Si Drift
Hybrid Pixels
Monolythic:CCD, MAP
3-D
Large Area
n n n
nnp p
n
Double-sided
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Engineering of Silicon Detectors
Modeling (C. Piemonte, INFN Trieste)
Improve high voltage behavior of Si detectors
Recessed Metal: high field at the junction“Field Plate” = Metal overhangmoves high field to oxide (30x Breakdown strength)
Critical Field at junction reduced by factor 2
Papers # 497,455, 205, 184
metal
P+ - implant
oxide
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP The Rise of the Silicon Detectors
Olympic Motto in Silicon Detector Language
Altius Larger - CMS 10M Channels, 230m2Citius Faster - ATLAS 22nsFortius Cheaper - CMS ~$5/cm2
0.01
0.1
1
10
100
1000
1985 1990 1995 2000 2005 2010
Silicon Area [m2]
Year
CDF
ATLASGLAST
CMS
AMS-02
AMS-01
D0
BaBar
NOMAD
LEP
LPSCDFMark2
Pamela
Agile MEGA
1
10
100
1000
104
1985 1990 1995 2000 2005 2010
# of Electronics Channels [in k]
Year
CDF
ATLAS
GLAST
CMS
AMS-02
AMS-01
WIZARD
D0
BaBar
NOMAD
LEP
LPSCDFMark2 Pamela
Agile MEGA
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP The Rise of the Silicon Detectors
Edge joint and wire bonds before encapsulation
0.01
0.1
1
10
100
10 100 1000 104
Silicon Area vs. # of Electronics Channels
# of Channels [k]
CDF
ATLASGLAST
CMS
AMS-02
AMS-01 D0
BaBar
NOMAD
LEP
LPSCDF
Mark2 Pamela
Agile MEGA
Are
a[m
2 ]
Limited Resources (Power) in Space
Long Ladders possible with:Bonding and Encapsulation
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP The Rise of the Silicon Detectors
Trends in the Cost of Silicon Detectors
Cost of processing wafers reduced ~ 4x
Increased Area 4” -> 6”Better utilisation of area
Improved Qualitye.g. GLAST detectors:
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Signal in Tracking Detectors
Signal-to-Noise Ratio:Signal ~ ThicknessNoise ~ Area, 1/√τs
Charged Particle Energy Loss
Directional Information compromised byMultiple Scattering
Multiple Scattering angle
->Thin, low z materials-> Improves at High Energy
~1/ββββ2
MIP
Radmeasure p
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Milestones: Fixed Target
That’s how it all began
Fixed Target experiments withhigh rates:
Na11 (ACCMOR)Na14HeliosE691
Detect heavy decaying particles through their finite decay distance
Silicon Detectors~ 5cm x5cm
Fanout-Cables
Amplifiers
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Milestones: Vertex Detectors
The big step forward in Mark2:ASIC’s (Terry Walker et al)
Every LEP Experiment has aVertex Detectors:
Double-SidedAC-coupled
Vertex Detector ParadigmASIC’s,Few thin layers,Close in.
ALEPH
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Milestones: Speed and Rad.Hardness
LPS at HERA“Fixed Target” at ColliderImportance of Electronics:
rad hardfastlow noiselow power
56 planes, 50k channelsElliptical shapes!
2 chip set: Bipolar+CMOS
Radiation Effects:See Mara Bruzzi’s Talk On Wednesday, 14:15
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPPTracking Milestone: Ultimate Vertex Detectors
BaBar: Long ladders, bend profile, Electronics outside tracking volume
B-Factories:CM is moving, yet stilllow momentum particlesMinimize multiple scattering
Measure the decay time distribution via the difference in decay length between B and Bbar particle.
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Milestone: Measure Time
BaBar
Finite Life Timeof D Mesons
Performance inProposal and Experimentagree
Belle
Measurement of pulse height in double-sided detectors:Landau Distribution
Papers # 169, 293, 439, 456
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Milestones: Q.A.
Vertex Detector � Inner DetectorBoth D0 and CDF have ~500k channels
Change in Paradigm: coverage of large areaelectronics inside tracker volume
D0:ModularityYieldTesting Alignment
Paper # 536
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Milestones: Highest Luminosity LHC
ATLAS: Silicon TrackerSimple Detectors,Optimized Electronics
Thermal Management in ModulesSelf heating of rad. damaged detectorsUse of heat spreader (PG) in a Si-PG-Si sandwich
Temperature Range : -17oC (cooling pipe) to +16oC (ASICs)
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Milestones: Highest Luminosity LHC
Silicon has arrived:all Silicon Inner DetectorSi Area 223m2, - 6” Wafers -
Continued Paradigm Change:Outside radius : ~1.1m~1R.L. in tracking volume
Papers # 545, 342, 363, 386
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking in Space: AMS
Very long ladders (65cm)Thin mechanical structuresElectronics outside trackingPrecision alignment
Tracking in Magnetic field:Minimize material
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking in Space: Sileye
SileyeInvestigate light flashes seen by Cosmo-/Astro-nauts duringOrbital flights.
Cosmonaut Adveev on Mir
Occurrence of Flashes well correlated with high flux ofCosmic ray particles.
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking in Medicine: NanoDosimetry
Measure interaction of radiation with matter (DNA) on the microscopic level
E2(strong)
ion
particle
δ electronvacuumlow pressure
gas
E1
ion counter
differential pumping
Fron
t-en
d E
lect
roni
cs -----------
Accelerator CycleSignal
DAQ Computer
PCI Bus
AnticoincidenceDiscriminator
Si MicrostipDetector 2
Fron
t-en
d E
lect
roni
cs
Data ReadoutBoard
VME Board
Time-to-DigitConverter
+ HV
PlasticScintillators
Degrader
PMTs
PrimaryParticle
Discriminator
0.5 sec
2.2 sec
Primary Particle Trigger
E, nx, ny
Ionization Cell-----------
Si MicrostipDetector 1
Apparatus uses Silicon Microstrip detectors to track protons and measure their energy by specific ionization ( dE/dx ).UC Santa Cruz
Based on drifting and counting ions frominteraction of proton beam with specimen.(Weizmann Inst., Loma Linda Hospital)
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP 2-D Tracking or Imaging Detectors : Pixels
Particle Rate vs Read-out FrequencyLow rate: Projective geometry of rotated silicon strip detectors works wellMedium rate: Small angle stereo, one coordinate is measured less wellHigh rate: truly 2-D detectors: Pixels Issues: Readout Speed, Power
Hybrid Pixels:Separate Detector and Readout Chip, Full Depletion Bump Bonding BTeV&ATLAS &CMS
Focus is on Readout Chipfor fast single photon countingwith good energy resolution50Hz readout of 1cm x 1cm
10 20 30 40 500.0
0.2
0.4
0.6
0.8
1.0
1.2Rb Mo Ag Ba Tb
Nor
mal
ised
Hei
ght
Energy [keV]Papers # 253, 355, 371, 372, 561, 766,
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking Detectors: CCD
3M pixel CCD device for SLDFew um resolution in two coordinates
Worked well for 120Hz SLC operationRadiation Hardness?
Proposed for LCReadout improved for high rate applications“Column parallel CCD”
Detached VertexesIn B and anti-B
Paper # 191
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP MonolythicActive Pixels Sensors
High Resistivity: S. Parker et alDon’t hear much about it anymore….
Low resistivity: CMOS“Detectors inside the Chip”Pixel contains diode and readout electronicsDiode coverage is only partial (1-4small diodes)~10um deep active area in epitaxyCollection within 150nsCollection by diffusion: 40% in central pixel
CMOS MIMOSA16k Pixels20um x 20umC = 3fFSignal: ~ 1000e-Noise:~30e-
Integration of Detector and Readout
CMOS Pixel Camera4M pixels, 20nW/pixel
Papers # 45, 46
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Tracking/Imaging: 3D Detector
Departure from Planar Technology.“Stonehenge” Architecture of columns of n- and p-implants in high resistivity bulk.
n n n
nnp p
n
Good S/N:Low Capacitance
Electrical properties Determined by implant separation ~100um: Low Depletion Voltage,good radiation resistance
Paper # 842
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP
λ varies by 105!
Photon Detection: How to Measure the Direction
Absorption coefficientλ = (7/9)/Xo
Absorption of PhtotonsN(x) = Noe- λ x
Optical-X-raysNeed Focus:LensesMirrorsCollimatorsCoded MasksProximity
ComptonPartial Direction
γ
calorimeter (energy measurement)
anticoincidenceshield
e+ e–
particle tracking detectors
conversion foil
Pair-ProductionDirection
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPPApplication: Optical Imaging with CCD’s
36k2
16k2
8k2
4k2
2000Year
20051990 1995 2010
2k×2k
MACHO
Suprime
UH4K
NOAO 4KCFHT MOCAM
NAOJ
BTC
RGO
UH8K EROS2 QUEST NOAO 8k
UW
DMT
WFHRI_1
SDSSCFH12K ESO OmegaCAM
NOAO 8k (thinned)3
3
3
107
108
109
1011
Nu
mber
of
pix
els
DEIMOSUH8K (thinned)MAGNUMCTIO 8kESO 8kMSSSO/WFI
CFHT MegacamSAO/MMT Megacam
1976
SNAPsat
SNAP: 200 CCD @ 10$each
Astronomy: CCD replaced film completely:
ideal match for
Astronomical observations.
long integration time,
long readout time,
low noise
BTC: 4 CCD @ 120k$ each
Progress:
Increase efficiency
Shining from the backside,
high resistivitycollect from bulk
X-rays: Chandra-Newton
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Application: Imaging with Hybrid Pixel Detector
• X-RAY ENERGY : 5 to 25 keV• PIXEL SIZE : 200 µm x 200 µm (~ ESRF source image )• COUNTING RATE : up to 10 7 photons/second/pixel• SENSITIVITY : 1 ph / pixel• DYNAMIC RANGE : 109 (32-bit counters)• REAL TIME STUDIES : up to 3 ms/frame with 128 frames capacity• DIMENSION : 250*250 mm• WEIGHT :
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP
X-ray source
object
aft-collimator
pre-collimator
scan direction
silicon strip detector
Strip Detectors in Medicine: Mammography
Large objects, “proximity focussing”Need large detectors!Scan collimated X-ray Source across Si strips
Excized breast tissue 5 cm x 7 cm x 4 cm at 0.3 mGy MGD
Gammex RMI phantom at 0.7 mGy MGD
Paper # 372, 627
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Strip Detectors in Medicine: Mammography
Stationary “Telescope” of Flat Synchrotron beam and Collimator and edge-on Si DetectorScan Sample/Patient.
Edge-on Si stripsHave high efficiencyNo Ghost problem= “Pixels”
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Application: Drift Detectors: Tracking & X-rays
Silicon drift chambersare used as 2-D tracking devices in HEP experiments (Star).Coordinate determined from drift time: savings in electronics channels.
Papers # 184, 300, 366, 377
For high rate X-ray application, need “time stamp”CCD+ Si-Drift = Controlled Drift Detector
Sawtooth Si Drift Detector for soft X-ray application, 200eV resolution @5keV
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Application: Compton Telescope
Compton effect: 2-body reaction correlates energy transfer with scattering angle
−−=
12
2 111cosEE
cmeϕPrecise Energy measurement of Compton electrons constrains the scattering angle.
T. Kamae: Multiple Compton scattersallow good determination of the incident angle, and energy
Thick Silicon detectors increase the conversion probability and energy resolution
Papers # 65 (for Ge)
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Application: Compton Camera in Medicine
Paper # 326
Compton Camera:Silicon detector measures the first scatterCalorimeter measures the energy and direction
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Application: Compton Telescope AstroPhysics
Classical Compton Event Circles
Reduced Compton circles of events with electron track
MEGAUse of electron directionto limit the Compton cone.
Paper # 449, 860
Stack of Silicon detectors
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP
1
2
Pair Conversion Telescope: GLAST
Paper # 88
GLASTPair Conversion Tracker:Photon reconstructed from the Conversion Pair tracked in Silicon Telescope
12 thin converters (2.5%R.L)4 thick converters (25%R.L)Single-sided Silicon detectors83m2, 10k detectors, 5M bonds1M channels,
IEEE2000: Silicon Detectors Hartmut F.-W. Sadrozinski , SCIPP, UC Santa Cruz
SCIPPSCIPP Success of Silicon Detectors
Micro strip- Tracking (HEP, Astro, Medicine)
Drift
Pixels
CCD Spectroscopy
3-D Optical Imaging (Astro)
AlignmentPads
Compton (Astro, Medicine)
X-ray Imaging (Medicine, X-talography
Exponential growth of Applicationof Silicon Detectors
- in size and channel numbers -
due to:•Improvement in quality•Maturity of designs •Sophistication of fabrication•Industrial base•Reduction in cost•Growth of expertise•Improvement of assembly•Progress in ASIC design
Driven by theimaginationin the application