1. RD50 STATUS REPORT 2006 Development of radiation hard sensors for very high luminosity colliders Mara Bruzzi 1 and Michael Moll 2 1 INFN Florence, Italy 2 CERN- PH-DT2 - Geneva - Switzerland 85 meeting of the LHCC, 15 November 2006 on behalf of RD50  The RD50 collaboration  Results obtained in 2006  Summary (Status Nov. 2006)  Work plan for 2007  Resources request for 2007 OUTLINE http://www.cern.ch/rd50

2. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -2- The CERN RD50 Collaboration http://www.cern.ch/rd50  approved as RD50 by CERN June 2002  Main objective:  Presently 264 members from 52 institutes Development of ultra-radiation hard semiconductor detectors for the luminosity upgrade of the LHC to 10 35 cm -2 s -1 (“Super-LHC”). Challenges:- Radiation hardness up to 10 16 cm -2 required - Fast signal collection (Going from 25ns to 10 ns bunch crossing ?) - Low mass (reducing multiple scattering close to interaction point) - Cost effectiveness (big surfaces have to be covered with detectors!) RD50: Development of Radiation Hard Semiconductor Devices for High Luminosity Colliders Belarus (Minsk), Belgium (Louvain), Canada (Montreal), Czech Republic (Prague (3x)), Finland (Helsinki, Lappeenranta), Germany (Berlin, Dortmund, Erfurt, Freiburg, Hamburg, Karlsruhe), Israel (Tel Aviv), Italy (Bari, Bologna, Florence, Padova, Perugia, Pisa, Trento, Turin), Lithuania (Vilnius), The Netherlands (Amsterdam), Norway (Oslo (2x)), Poland (Warsaw (2x)), Romania (Bucharest (2x)), Russia (Moscow), St.Petersburg), Slovenia (Ljubljana), Spain (Barcelona, Valencia), Switzerland (CERN, PSI), Ukraine (Kiev), United Kingdom (Diamond, Exeter, Glasgow, Lancaster, Liverpool, Sheffield), USA (Fermilab, Purdue University, Rochester University, SCIPP Santa Cruz, Syracuse University, BNL, University of New Mexico)

3. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -3- Scientific Organization of RD50 Development of Radiation Hard Semiconductor Devices for High Luminosity Colliders Spokespersons Mara Bruzzi, Michael Moll INFN Florence, CERN ECP Defect / Material Characterization Bengt Svensson (Oslo University) Defect Engineering Eckhart Fretwurst (Hamburg University) Pad Detector Characterization G. Kramberger (Ljubljana) New Structures R. Bates ( Glasgow University) Full Detector Systems Gianluigi Casse ( Liverpool University) New Materials E: Verbitskaya (Ioffe St. Petersburg) Characterization of microscopic defects properties of standard-, defect engineered and new materials pre- and post-irradiation Defect engineered silicon: Epitaxial Silicon CZ, MCZ Other impurities H, N, Ge, … Thermal donors Pre-irradiation Oxygen Dimer Development of new radiation tolerant materials: SiC GaN other materials Test structure characterization IV, CV, CCE NIEL Device modeling Common irrad. Standardization of measurements Evaluation of new detector structures 3D detectors Thin detectors Cost effective solutions Semi 3D LHC-like tests Links to HEP Links to R&D on electronics Comparison: pad-mini-full detectors Pixel group  2006: Research Line “New Materials” suppressed  R&D performed by RD50 on SiC and GaN did not show promising results  Activity within RD50 reduced on Working Group level to conclude the started work program

4. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -4- RD50 approaches to develop radiation harder tracking detectors  Material Engineering -- Defect Engineering of Silicon  Understanding radiation damage Macroscopic effects and Microscopic defects Simulation of defect properties & kinetics Irradiation with different particles & energies  Oxygen rich Silicon DOFZ, Cz, MCZ, EPI  Oxygen dimer & hydrogen enriched Silicon  Pre-irradiated Silicon  Influence of processing technology  Material Engineering -- New Materials (work concluded within RD50)  Silicon Carbide (SiC), Gallium Nitride (GaN)  Device Engineering (New Detector Designs)  p-type silicon detectors (n-in-p)  thin detectors  3D detectors  Simulation of highly irradiated detectors  Semi 3D detectors and Stripixels  Cost effective detectors Related Works – Not conducted by RD50  “Cryogenic Tracking Detectors” (CERN RD39)  “Diamond detectors” (CERN RD42)  Monolithic silicon detectors  Detector electronics (Some work within RD50 on SiGe electronics)

5. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -5- Silicon Materials under Investigation by RD50 MaterialSymbol  (  cm) [O i ] (cm -3 ) Standard FZ (n- and p-type) FZ 1–7  10 3 < 5  10 16 Diffusion oxygenated FZ (n- and p-type) DOFZ 1–7  10 3 ~ 1–2  10 17 Magnetic Czochralski Si, Okmetic, Finland (n- and p-type) MCz ~ 1  10 3 ~ 5  10 17 Czochralski Si, Sumitomo, Japan (n-type) Cz ~ 1  10 3 ~ 8-9  10 17 Epitaxial layers on Cz-substrates, ITME, Poland (n- and p-type, 25, 50, 75, 150  m thick) EPI 50 – 400 < 1  10 17 Diffusion oxygenated Epitaxial layers on CZ EPI–DO 50 – 100 ~ 7  10 17  DOFZ silicon - Enriched with oxygen on wafer level, inhomogeneous distribution of oxygen  CZ/MCZ silicon - high Oi (oxygen) and O 2i (oxygen dimer) concentration (homogeneous) - formation of shallow Thermal Donors possible  Epi silicon - high O i, O 2i content due to out-diffusion from the CZ substrate (inhomogeneous) - thin layers: high doping possible (low starting resistivity)  Epi-Do silicon - as EPI, however additional O i diffused reaching homogeneous O i content “new” in 2006

6. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -6-  CIS Erfurt, Germany  2005/2006/2007 (RD50): Several runs with various epi 4” wafers only pad detectors  CNM Barcelona, Spain  2006 (RD50): 22 wafers (4”), (20 pad, 26 strip, 12 pixel),(p- and n-type),(MCZ, EPI, FZ)  2006 (RD50/RADMON): several wafers (4”), (100 pad), (p- and n-type),(MCZ, EPI, FZ)  HIP, Helsinki, Finland  2006 (RD50/RADMON): several wafers (4”), only pad devices, (n-type),(MCZ, EPI, FZ)  2006 (RD50) : pad devices, p-type MCz-Si wafers, 5 p-spray doses, Thermal Donor compensation  2006 (RD50) : full size strip detectors with 768 channels, n-type MCz-Si wafers  IRST, Trento, Italy  2004 (RD50/SMART): 20 wafers 4” (n-type), (MCZ, FZ, EPI), mini-strip, pad 200-500  m  2004 (RD50/SMART): 23 wafers 4” (p-type), (MCZ, FZ), two p-spray doses 3E12 amd 5E12 cm -2  2005 (RD50/SMART): 4” p-type EPI  2006 (RD50/SMART): new SMART mask designed  Micron Semiconductor L.t.d (UK)  2006 (RD50): 4”, microstrip detectors on 140 and 300  m thick p-type FZ and DOFZ Si.  2007 (RD50): 93 wafers 6”, (p- and n-type), (MCZ and FZ), (strip, pixel, pad)  Sintef, Oslo, Norway  2005 (RD50/US CMS Pixel) n-type MCZ and FZ Si Wafers  Hamamatsu, Japan  In 2005 Hamamatsu started to work on p-type silicon in collaboration with ATLAS upgrade groups (surely influenced by RD50 results on this material) Process of Si sensors in framework of RD50 M.Lozano, 8 th RD50 Workshop, Prague, June 2006 A.Pozza, 2 nd Trento Meeting, February 2006 G.Casse, 2 nd Trento Meeting, February 2006 D. Bortoletto, 6 th RD50 Workshop, Helsinki, June 2005 N.Zorzi, Trento Workshop, February 2005  Recent production of Silicon Strip, Pixel and Pad detectors (non exclusive list) : … all available wafer types processed, we have more detectors than can be tested …

7. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -7- Reminder: Radiation Damage in Silicon Sensors Two general types of radiation damage to the detector materials:  Bulk (Crystal) damage due to Non Ionizing Energy Loss (NIEL) - displacement damage, built up of crystal defects – I.Change of effective doping concentration (higher depletion voltage, under- depletion) II.Increase of leakage current (increase of shot noise, thermal runaway) III.Increase of charge carrier trapping (loss of charge)  Surface damage due to Ionizing Energy Loss (IEL) - accumulation of positive in the oxide (SiO 2 ) and the Si/SiO 2 interface – affects: interstrip capacitance (noise factor), breakdown behavior, … Impact on detector performance and Charge Collection Efficiency (depending on detector type and geometry and readout electronics!) Signal/noise ratio is the quantity to watch  Sensors can fail from radiation damage ! Same for all tested Silicon materials! Influenced by impurities in Si – Defect Engineering is possible!

8. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -8- Standard FZ, DOFZ and MCz Silicon Situation in 2004/2005:  Standard FZ silicon type inversion at ~ 2  10 13 p/cm 2 strong N eff increase at high fluence  Oxygenated FZ (DOFZ) type inversion at ~ 2  10 13 p/cm 2 reduced N eff increase at high fluence  MCZ silicon  no type inversion (SCSI) in the overall fluence range  donor generation (and lower V 2 O production) overcompensates acceptor generation in high fluence range Situation in 2006: more complex and partly confusing 24 GeV/c proton irradiation [1] M. Moll et al. NIM A 546 (2005), 99-107 [2] data on [1] related 380  m-thick devices here normalised to 300  m [3] E. Tuovinen et al. In press on NIM A [4] M. Moll et al. RD50 workshop, CERN Nov. 2005 n-type MCZ more radiation tolerant than n-type DOFZ

9. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -9- Proton irradiated n- and p-type MCz Do we undergo SCSI (i.e. movement of the main junction)? Fluence dependence (24 GeV/c) Annealing @ 80°C SCSI at late stage Typical for n-type “Reverse annealing is beneficial”  Cz, MCz-n No SCSI; verified by TCT & annealing curves  MCz-p ?? (SCSI expected, see annealing data to the right)  However, after 10-30 MeV proton irradiation shape of annealing curves indicate that n - MCz detectors undergo SCSI (J. Harkonen NIM A541, p202, SMART coll. 7th RD50 workshop) G. Kramberger, RESMDD06, Oct 2006 V. Cindro et al., 8th RD50 workshop

10. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -10- Neutron irradiated Cz/MCz V. Cindro et al., 8 th RD50 workshop N. Manna for SMART, 8 th RD50 workshop G.Kramberger, RESMDD06, October 2006 After neutron irradiation (almost) all materials behave similarly!  MCz-n undergoes SCSI (confirmed by TCT, annealing curve)  Stable damage (slope in curve) same for all materials  Beneficial and reverse annealing similar between FZ, DOFZ and MCZ  Lower resistivity n-type has the advantage of later SCSI

11. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -11-  Epitaxial silicon  Thickness: 25, 50  m (~ 50  cm), 75  m (~ 150  cm); New in 2006: 150  m (~ 400  cm)  Advantage: Only little change in depletion voltage up to 10 16 particles/cm 2  Proton irradiations (2005) demonstrated: No type inversion up to ~ 10 16 p/cm 2  Neutron irradiations(2005): No type inversion up to ~ 10 16 n/cm 2 (25, 50  m thick layers) EPI Devices – Irradiation experiments G.Lindström et al.,10 th European Symposium on Semiconductor Detectors, 12-16 June 2005 G.Kramberger et al., Hamburg RD50 Workshop, August 2006  CCE (Sr 90 source, 25ns shaping):  6400 e (150  m; 2x10 15 n/cm -2 )  3300 e (75  m; 8x10 15 n/cm -2 )  2300 e (50  m; 8x10 15 n/cm -2 ) 2006: Annealing typical for p-type observed  SCSI observed for  >150  cm (to be verified ??) Neutron irradiation 2006 Depletion Voltage: 35V (25  m) 120V (50  m) 220V (75  m) 320V (150  m)

12. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -12- N eff changes - Summary “reverse annealing” almost same for all materials (delayed by higher [O]) using Epi/MCz/Cz gives possibility to storage at room temperature due to compensation. Epi-n most tolerant material for neutron damage! Stable damage24 GeV protonsReactor neutrons FZ (n- and p-type) -- DOFZ (n- and p-type) -- MCz/Cz (n-type) +- MCz (p-type) ??- Epi (n-type) ++/- (depends on  )  Net space charge increase during irradiation (is positive or negative space charge added ?) Reminder for non experts: n-type = positive space charge p-type = negative space charge

13. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -13- p-on-n silicon, under-depleted: Charge spread – degraded resolution Charge loss – reduced CCE p + on-n Device engineering p-in-n versus n-in-p detectors n-on-p silicon, under-depleted: Limited loss in CCE Less degradation with under-depletion Collect electrons (fast) n + on-p n-type silicon after high fluences: p-type silicon after high fluences: Be careful, this is a very schematic explanation, reality is more complex (e.g. double junction)!

14. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -14- n-in-p microstrip detectors  n-in-p microstrip detectors on p-type FZ (280  m thick, 80  m pitch, 18  m implant )  Detectors read-out with 40MHz n-in-p: - no type inversion, high electric field stays on structured side - collection of electrons  acceptable agreement between simulation and measurement  no reverse annealing visible in the CCE measurement ! Possible explanation: Reverse annealing of V fd compensated by smaller trapping of electrons.

15. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -15- 3D – Single Column Type (1/2) ionizing particle cross-section between two electrodes n+n+ n+n+ electrons are swept away by the transversal field holes drift in the central region and diffuse towards p+ contact p-type substrate n + electrodes Uniform p+ layer  Simplified 3D architecture  n + columns in p-type substrate, p + backplane  operation similar to standard 3D detector  Simplified process  hole etching and doping only done once  no wafer bonding technology needed  single side process (uniform p + implant) p-stop metal n+n+ strip detector

16. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -16- M. Scareingella, STD6, September 2006 Tests on diode and microstrip structures 3D – Single Column Type (2/2) G. Kramberger et al., 8 th RD50 workshop 2006  CCE measurements before irradiation  90 Sr electrons - shaping time 400ns  300  m thick MCz Si; 100% CCE at 30- 60V  CCE in agreement with CV analysis  Position sensitive TCT (laser beam ~ 7  m with 3 amplifiers monitoring induced currents)  charge collection within 20ns  First irradiations performed  low depletion voltage after irradiation  CCE measurements are under way 300  m C.Piemonte, STD6, September 2006 20 ns

17. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -17- Outlook: 3D – Double Column Type  Two processes under way  CNM, Spain and Uni. of Glasgow, UK  ITC-IRST, Trento, Italy  Simplified processing due to “incomplete drilling”  First detectors expected in early 2007  Different structures on the mask  ATLAS pixel, Medipix 2  strip detectors, 3D pads  Pilatus Pixels, MOS test structures, etc.

18. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -18- strips pixels [1] G. Casse et al. NIM A (2004) [2] M. Bruzzi et al. STD06, September 2006 [3] G. Kramberger, RD50 Work. Prague 06 [4] W: Adams et al. NIM A (2006) [5] F. Moscatelli RD50 Work.CERN 2005 [6] C. Da Vià, "Hiroshima" STD06 (charge induced by laser) Comparison of measured collected charge on different radiation-hard materials and devices Line to guide the eye for planar devices 160V M. Bruzzi, Presented at STD6 Hiroshima Conference, Carmel, CA, September 2006  Thick (300  m) p-type planar detectors can operate in partial depletion, collected charge higher than 12000e up to 2x10 15 cm -2.  Most charge at highest fluences collected with 3D detectors  Silicon comparable or even better than diamond in terms of collected charge (BUT: higher leakage current – cooling needed!)

19. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -19- - Status 2006 ( I ) -  Inner radius (20-60 cm) – essential to use n + readout (n + -in-n or n + -in-p)  MCZ, CZ silicon detectors could be a cost-effective radiation hard solution small stable damage (small increase of depletion voltage with fluence) beneficial long term annealing:- compensation of donors with acceptors - effective electron trapping getting smaller drawback: n-type not very tolerant to neutrons  EPI detectors (providing that p-type EPI has the same properties as n-type EPI) All benefits of MCZ and CZ detectors + more tolerant to neutron damage drawback: Smaller charge as devices are thin, presently 150  m, (needs to be optimized)  Oxygenated p-type silicon microstrip detectors show very encouraging results: CCE  6500 e;  eq = 4  10 15 cm -2, 300  m No degradation visible in long term CCE measurements  Outer radius (60-120 cm) – large area p + readout maybe more cost effective  MCZ/CZ n-type Si, low resistivity gives prolonged time to type inversion (incomplete donor removal)  DOFZ-n (same as for MCZ/CZ) At fluences up to 10 15 cm -2 (Outer layers of a SLHC detector) the change of the depletion voltage and the large area to be covered by detectors is the major problem.

20. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -20- - Status 2006 ( II ) -  Thinner/EPI detectors: – n + readout (n + -in-n or n + -in-p), smartly segmented  beneficial long term annealing – room temperature maintenance beneficial  tested up to 150  m thickness (smaller capacitance, better initial performance).  drawback: epi-p needs still more tests  thickness tested: up to 150  m  CCE measured with 90 Sr e, shaping time 25 ns, 75  m, Φ eq =8·10 15 cm -2  3200 e (mp-value)  3D detectors: 3D-stc processed at IRST-Trento  Good process yield and low leakage currents (< 1pA/column)  Breakdown @ 50V for p-spray and >100V for p-stop structures  CCE 100% before irradiation  first radiation hardness tests under way  3D with 2-type columns will be produced in 2007 At the fluence of 10 16 cm -2 (Innermost layers of a SLHC detector) the active thickness of any silicon material is significantly reduced due to trapping.

21. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -21- Comment on links to LHC Experiments  Many RD50 groups are directly involved in ATLAS, CMS and LHCb upgrade activities (natural close contact). They report regularly to RD50 members and management.  We are and were invited to present the RD50 work on ATLAS and CMS upgrade meetings (transfer of knowledge)  Devices matching ATLAS and CMS strip and pixel readout patterns on all recent RD50 4” and 6” masks !  LHC speed front-end electronics (ATLAS, CMS and LHCb (soon)) used by RD50 members  CMS/RD50 groups gathered to set up a beam telescope for future test beams of newly developed strip detectors  3D detectors will be provided to ATLAS Pixel for beam tests (already agreed)  MCZ wafers provided by RD50 to CMS Pixel for processing at Sintef  ….

22. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -22- Workplan for 2007 (1/2)  Characterization of irradiated silicon:  Understand role of defects in annealing of p- and n-type MCz vs FZ Si  Continue study on oxygen dimers  Extend studies on neutron irradiated MCz & FZ Si  Understand role of carbon and hydrogen better  Continue study of epitaxial Si of increased thickness and p-type  Production of epitaxial silicon on FZ substrate  Hydrogenation of silicon detectors  Test uniformity of MCZ p-type silicon over the wafer  Characterization (IV, CV, CCE with  - and  -particles) of test structures produced with the common RD50 masks  Common irradiation program with fluences up to 10 16 cm -2  Clarification of the situation regarding the type inversion of MCZ silicon (parameterization of radiation damage w.r.t N eff ) Defect Engineering Defect and Material Characterization Pad Detector Characterization

23. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -23- Workplan for 2007 (2/2)  Production of 3D detectors made with n + and p + columns  Measurement of charge collection after irradiation of the processed single type column 3D detectors  Comparison of thin (140  m) and thick (300  m) strip detectors produced in 2006.  Irradiation and test (CCE of strip detectors with fast electronics) of common segmented structures (n- and p- type FZ, DOFZ, MCz and EPI) on 4” and 6” wafers (Within RD50 common irradiation programs)  Long term annealing of segmented sensors  Investigation of the electric field profile in irradiated segmented sensors  Continue and strengthen activities linked to LHC experiments – achiever closer link to LHC experiments upgrade activities (e.g. common projects, test beams) New Structures Full Detector Systems

24. RD50 Mara Bruzzi and Michael Moll on behalf of the RD50 CERN Collaboration – LHCC, November 13, 2006 -24- Resources requested for 2007  Common Fund: RD50 has a Common Fund and does not request financial support.  Lab space and technical support at CERN: As a member of the collaboration, the section PH-DT2/SD should provide (as in 2006) access to available lab space in building 14 (characterization of irradiated detectors), in building 28 (lab space for general work) and in the Silicon Facility (hall 186, clean space).  CERN Infrastructure: - One collaboration workshop in November 2007 and working group meetings. - Keeping the RD50 office in the barrack 591