1. p-on-n Strip Detectors: ATLAS & CMS
Single-Sided Lithographic Processing
( AC, Poly-Si biasing )
Radiation hardness “recipe”
P-on-N sensors work after bulk type inversion,
Provided they are biased well above depletion
Match sensor resistivity & thickness to fluence
To optimize S/N over the full life-time
Follow simple design rules for guard & strip geometry
Use Al layer as field plate to remove high field
@edges from Si bulk to Oxide (much higher Vbreak)
Strip width/pitch ~ 0.25: reduce Ctot maintain
Stable high bias voltage operation
Take care with process: especially implants…
Surface radiation damage can
increase strip capacitance & noise
Use <100> crystal instead of <111>
N Bulk
N+ Implants
P+ implants
Al Strips
“P” Bulk
+++++
-----
Surface damage
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

2. ATLAS Transition Radiation Detector
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

3. ATLAS TRD Information Alessia Tricomi - University & INFN Catania
EPS July, Aachen

4. ATLAS TRD: e-p separation
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

5. ATLAS TRD: particle identification
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

6. The CMS Pixel detector Alessia Tricomi - University & INFN Catania
EPS July, Aachen

7. The CMS Pixel detector: barrel modules
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

8. The CMS Pixel Detector: endcap disks
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

9. 0.25m FE chip set: Production wafer layout
Full Chip set tested, production well underway
APV25 8” Wafer
Overall size 200mm
APV25 die ≈ 400
APVMUX+PLL die ≈ 100
Use IBM 0.25m technology
APV25 chip: excellent noise performance
Shaping time in deconvolution ~ 25ns
Radiation insensitive
Excellent noise performance
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

10. APV25 Test Results Automatic wafer probing
Allows systematic monitoring of yield
Crucial to provide feed-back to foundry on process quality to ensure adequate yield is maintained
Two cut wafers retested as individual die
statistics limited: upper limit 1% good die failed
but no bad chips accepted
Test time < 2mins/chip
1 8inch wafer per probe station per day
can complete testing in ~1-2 years
Irradiation results
x-ray, pion & neutron - all excellent
tests with heavy ions and pions
8 chips x 10 LHC years
low SEU rate, no permanent damage or latch up
“Typical” tested wafer map
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

11. Silicon Sensor Geometry
Strip capacitance ~ 1.2pF/cm for w/p = 0.25
Independent of pitch and thickness
Insensitive to irradiation
for <100> crystal lattice
Expected S/N after irradiation
S/N ~ 13 for thin sensors, short strips
S/N ~ 15 for thick sensors, long strips
Use 320mm thick Si for R < 60cm, Strip ~ 10cm
Use 500mm thick Si for R > 60cm, Strip ~ 20cm
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

12. Track Reconstruction (CMS)
Generation of seeds (Seed Generator)
Construction of trajectories for a given seed (Trajectory Builder)
Ambiguity resolution (Trajectory Cleaner)
Final fit of trajectories (Trajectory Smoother)
Each component has one or more implementation.
Three different algorithms are currently fully implemented: ( Combinatorial Track Finding, Connection Machine, Deterministic Annealing Filter)
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

13. ATLAS Reconstruction Sw
Inner Detector Layout
DC1
Initial
b-layer radius
5 cm
longitudinal pixel size in b-layer
300
400
2nd pixel layer
present
absent
pixel disk -#2, forward TRT wheels
Software used
iPatRec
Rel. 4.x athena reconstruction equivalent to atrecon
Rel. 5.x old EDM validated for DC1 Layout
Rel new “HLT” EDM validated for Pixels/SCT
xKalman
Rel using RD event to get truth association
new EDM possible but not used because truth missing
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

14. CMS Secondary Vertex Reconstruction: Principal Vertex Reconstructor
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

15. PV Resolutions and pulls
Alessia Tricomi - University & INFN Catania
EPS July, Aachen

16. BJ/yf resolutions and pulls
Alessia Tricomi - University & INFN Catania
EPS July, Aachen