Three R

1
CERN RD50 Collaboration
CERN RD50 project Main objective Develop
radiation hard semiconductor detectors that can
operate beyond the limits of present devices for
the luminosity upgrade of the LHC (Super-LHC)
which will bring 10 times higher radiation levels.

• Three RD strategies
• Material engineering- Defect engineering of
  silicon (oxygenation, dimers, )- New detector
  materials (SiC, )
• Device engineering- Improvement of present
  planar detector structures (3D detectors, thin
  detectors, cost effective detectors,)
• Variation of detector operational conditions-
  Low temperature operation- Forward bias
  operation
• Further key tasks
• Basic studies
• Defect modeling and device simulation

RD50Center of gravity

2
CERN RD50 Collaboration

• Involvement of PH-TA1-SD in 2003 Alison
  (Doctoral Student since September), Christian,
  
  Maurice, Michael, Veronique
• Direct involvement in the following research
  projects
• Oxygen dimer enriched silicon (Veronique,
  Michael)
• Czochralski and epitaxial silicon as detector
  material (Alison, Michael)
• Detector design development (Michael outside
  collaborators)

• Irradiations for RD50, inclucing dedicated high
  flux run to reach 1016 p/cm2 (Maurice, Michael)

• Management of Collaboration - Michael
  (CERN contact person and since July Deputy
  Spokesperson) - Christian (Budget holder and
  advice in many aspects)
• Administration of members (270 Members from 51
  Institutes), link to users office, web-pages,
  computer accounts, etc.
• Organization of Workshops in May and November
  (80 participants, 35 talks) Since October
  help from Secretary Dawn Hudson will continue
  for workshops in 2004.

• Changes in 2004 Alison (6 months), Christian,
  Maurice, Michael, Veronique (until end of April)
• Conclude the dimer program, step out of the
  detector design development
• Test of p-type silicon (also Czochralski) as
  detector material

3
Czochralski silicon (CZ)

• Very high Oxygen content 1017-1018cm-3 (Grown in
  quartz (SiO2)crucible)
• High resistivity (gt1KWcm) available only recently
  (Magnetic CZ technology)
• CZ wafers cheaper than FZ (RF-IC industry got
  interested)

• Irradiation of test-structures
• Only small change in Vdep
• 11015 (190 MeVp)/cm2
• 11015 (24 GeV/c p)/cm2
• 51014 (10 MeV p)/cm2
• No type inversion (Sumitomo CZ) (However,
  type inversion observed for Okmetic MCZ after
  51014 (10 MeV p)/cm2 )
• Leakage current and charge trapping
  as for FZ silicon
• Very high oxygen content Beware of thermal
  donors !

24 GeV/c p
4
Defect Engineering Oxygen Dimers in Silicon

• Idea Transform Oxygen into Oxygen dimers (O2)
• Standard Si VO?VO VVO ?V2O
• Dimered Si VO2?VO2 VVO2 ?V2O2

deep acceptor (neg. charged)
Simulations deep acceptor (but shallower
than V2O) ?neutral in SCR ?

• How to produce silicon containing dimers ?
• Co60-g or electron irradiation at 350ºC VO?VO
  VOO ?VO2 IVO2 ?O2
• Does it work ?

5
Laboratory in Building 28
TCT - Measurements

• CV-IV Measurements

• Details (set-up still under development)
• Pelletier cooled sample holder nitrogen gas flow
• Lasers 1060, 660 nm (produced by Maurice)
• Voltage source Keithley2410
• Scope Agilent Infinium
• Pulse Agilient 81104A
• Lab View program
• b source

• Details
• Alessi probe station
• Voltage source/current meter Keithley237,
  Keithley2410
• LCR meter Agilent 4263B
• Lab View program

• Planned improvements
• Automated temperature measurement
• improve flexibility of software

Summer StudentAlzbeta Helienek
2003 Visitor Akhil Jhingan 2004 Alison
Gouldwell-Bates
6
stop no more than 5 slides !!
7
Laboratories in 28-2
Meeting room RD50 visitors
Solid State Detector Laboratory
Michael and Veronique
Lab now used by Enrico Chesi
Christian
Lab borrowed to RD39 (should be
given back to us in very near future)

Alison visitors

• air condition
  (2-019/2-026)
• electricity system renovated (2-019/2-026)
• water
  (2-019/2-026)
• compressed air (2-019)

8
Laboratory in Building 28

• Laminar Flow Bench

• Clean room class 10 in the lab?
• less than 6 particles of size gt 0.3mm per
  cubic feet measured
• no particles of size gt 0.5mm per cubic feet
  measured

Deep Freezer Transportable deep freezer