1. Prochaines Etapes des Capteurs CMOS Christine Hu-Guo (IPHC)
PHASE1 – STAR IPHC

2. Trends for Pixel Sensor Development
CCD (Charge Coupled Device)
Future subatomic physics experiments need detectors  beyond the state of the art
MAPS provide an attractive trade-off between granularity, material budget, readout speed, radiation tolerance and power dissipation
Power consumption
Limited for all experiments
3T pixel
Analogue RO MAPS
MAPS Development Trend
Digital RO MAPS
3DIT
High resistivity EPI
2D & 3D MAPS
Hybrid Pixel Detector
22-24/06/ Journées VLSI IN2P3
IPHC

3. Development of MAPS for Charged Particle Tracking
In 1999, the IPHC CMOS sensor group proposed the first CMOS pixel sensor (MAPS) for future vertex detectors (ILC)
Numerous other applications of MAPS have emerged since then
~10-15 HEP groups in the USA & Europe are presently active in MAPS R&D
Original aspect: integrated sensitive volume (EPI layer) and front-end readout electronics on the same substrate
Charge created in EPI, excess carriers propagate thermally, collected by NWELL/PEPI , with help of reflection on boundaries with P-well and substrate (high doping)
Q = 80 e-h / µm  signal < 1000 e-
Compact, flexible
EPI layer ~10–15 µm thick
thinning to ~30–40 µm permitted
Standard fabrication technology
Cheap, fast turn-around
Room temperature operation
Attractive balance between granularity, material budget, radiation tolerance, read out speed and power dissipation
BUT
Very thin sensitive volume  impact on signal magnitude (mV!)
Sensitive volume almost un-depleted  impact on radiation tolerance & speed
Commercial fabrication (parameters)  impact on sensing performances & radiation tolerance
NWELL used for charge collection  restricted use of PMOS transistors
R.T.
22-24/06/ Journées VLSI IN2P3
IPHC

4. Progress on MAPS' Development
22-24/06/ Journées VLSI IN2P3
IPHC

5. Milestone of the Development
2009, an important year for CMOS pixel sensors' R&D: MIMOSA26 (Collaboration IRFU-IPHC) has been designed, fabricated and tested within the EUDET program
MIMOSA26: a reticule size MAPS for the beam telescope EUDET
Pixel array: 1152 x 576, 18.4 µm pitch
Binary output, 10 k images / s
Architecture:
Pixel (Amp+CDS) array organised in // columns r.o. in the rolling shutter mode
1152 ADC, a 1-bit ADC (discriminator) / column
Integrated zero suppression logic
Remote and programmable
Lab. and beam tests: 62 chips tested, yield ~75-90%
ULTIMATE: final sensor for STAR detector upgrade
Submission Oct. 2010
 See I. Valin's talk
2D MAPS have reached necessary prototyping maturity for real scale applications :
Beam telescopes allowing for sp ~ 2 μm & 106 particles/cm2/s (Beam results 06/2010)
Vertex detectors requiring high resolution & very low material budget
21.5 mm
13.7 mm
MIMOSA26
Active area: ~10.6 x 21.2 mm2
22-24/06/ Journées VLSI IN2P3
IPHC

6. MAPS: A Long Term R&D Main objective: ILC, with staggered performances
MAPS applied to other experiments with intermediate requirements
EUDET 2007/2009
Beam Telescope
EUDET (R&D for ILC, EU project)
STAR (Heavy Ion physics)
CBM (Heavy Ion physics)
ILC (Particle physics)
HadronPhysics2 (generic R&D, EU project)
AIDA (generic R&D, EU project)
FIRST (Hadron therapy)
ALICE/LHC (Heavy Ion physics)
EIC (Hadronic physics)
CLIC (Particle physics)
SuperB (Particle physics) …
STAR 2012
Solenoidal Tracker at RHIC
ILC >2020
Internatinal Linear Collider
CBM 2016
Compressed Baryonic Matter
 Spinoff: Interdisciplinary Applications, biomedical, space …
22-24/06/ Journées VLSI IN2P3
IPHC

7. Prototype R&D  Real Scale Detector R&D
22-24/06/ Journées VLSI IN2P3
IPHC

8. R&D Directions (1) Large surface detector  minimize dead zone
AIDA, CBM, EIC, biomedical imaging
Surface > reticle size (~2x2 cm²)
Stitching technique
Technologies:
XFAB 0.35 µm
Tower 0.18 µm
Problems:
Process: yield / wafer
Electronics: cap vs RO speed
22-24/06/ Journées VLSI IN2P3
IPHC

9. R&D Directions (2)
PLUME (Pixelated Ladder with Ultra-low Material Embedding) Project
Study a double-sided detector ladder motivated by the R&D for the ILD vertex detector at ILC
Material budget
<~0.3%XO
Mechanical investigation
Electrical investigation
EMC : Electro-Magnetic Compatibility
Power pulsing
Data transmission (few Gbit/ladder) Optical link?
SERWIETE (SEnsor Raw Wrapped In an Extra Thin Envelope) Project
Motivated by HadronPhysics2, FP7
Sensor assembly mounted on flex and wrapped in  polymerised film with <0.15 % Xo for 1 unsupported  layer (sensors – flex cable – film)
to evaluate the possibility of mounting a supportless  ladder on a cylindrical surface like a beam pipe (used  as mechanical support). Proof of principle expected in 2012 
Collaboration with IMEC
Fully functional microprocessor chip in flexible
plastic envelope. Courtesy of Piet De Moor,
IMEC company, Belgium
22-24/06/ Journées VLSI IN2P3
IPHC

10. R&D Directions (3): R&D on Microelectronics Design
Requests by projects in real conditions:
Pixel design:
Advanced processes:
High resistivity EPI layer (thickness, R)
Pitch, size
 Optimisation:
Charge collection efficiency
Resolution
Radiation hardness
Common submission IRFU-IPHC
Elongated pixel
Matrix for resolution
Matrix for time stamp
22-24/06/ Journées VLSI IN2P3
IPHC

11. R&D Directions (3): R&D on Microelectronics Design
Requests by projects in real conditions:
Pixel design
Integration ADC with pixel array  see F. Morel's talk
3D-MAPS  see O. Torheim's talk
Intelligent data processing blocks (DSP in chip?)
Cluster reconstruction (track position)
Data compression
SEU, SEL free circuit, ex. memory
Slow control & Data acquisition system  see C. Santos's talk
Power supply block  power management?
Data transmission  optical trans-receiver
Club 0.35/0.13
22-24/06/ Journées VLSI IN2P3
IPHC

12. Conclusion
After 10 year, 2D-MAPS R&D reaches its maturity for real scale applications
R&D continues: new performance scale accessible with emergent CMOS fabrication technology allowing to fully exploit the potential of MAPS approach
CBM, ALICE/LHC, EIC, CLIC, SuperB, …
 System integration (PLUME , SERWIETE) + Intelligent data processing + data transmission
Mediate & long term objective: 3D sensors mainly motivated by RO < few µs
Ultimately: expect to become the best performing pixel technology ever …?
22-24/06/ Journées VLSI IN2P3
IPHC