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Overview

Overview. History of silicon for tracking detectors & Basics From LHC tracker to SLHC tracker Radiation effects in silicon - defect engineering Device engineering – radiation hard device design Signal formation Isolation techniques Silicon detectors for SLHC n + -p strip detectors

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Overview

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  1. Overview • History of silicon for tracking detectors & Basics • From LHC tracker to SLHC tracker • Radiation effects in silicon - defect engineering • Device engineering – radiation hard device design • Signal formation • Isolation techniques • Silicon detectors for SLHC • n+-p strip detectors • n+-p pixel detectors • 3D detectors • Electronics considerations • Conclusions G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  2. History and basics G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  3. Position sensitive silicon detectors Planar diodes – structured detectors (Kemmer 1980) photolitografic processing G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  4. First considerations about radiation hardness for HEP - SSC (Detectors and Experiments for the Superconducting Super Collider, pg. 491, Snowmass 1984 1984 considerations for SSC (Detectors and Experiments for the Superconducting Super Collider, pg. 491, Snowmass 1984 Now 105 upra “Silicon strip detectors (near the beam pipe) appear to be limited to…≤ 1032....the 1032 limit could be optimistic.” (PSSC Summary Report pg. 130, 1984) T. Kondo et al, Radiation Damage Test of Silicon Microstrip Detectors, pg. 612, Snowmass 1984 G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  5. And we are we know now … LEPHERA , TevatronLHC SLHC? pp 1.4∙1032 cm-2 s-1 pp 1035 cm-2 s-1 e+e- 1.5∙1031 cm-2 s-1 • Silicon is a reliable detector technology • Available on large scale (200 m2 CMS) by many vendors with high yield • 6’’ wafers are standard, 8’’ are coming • Different silicon growing techniques can be exploited for sensor production • (CZ, MCz, FZ, epi-Si) • Many different electronics read-out ASICs were developed • Also other devices are interesting for tracking: CCD, MAPS, DEPFETs … G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  6. Silicon detectors today Signal ~ 22500e in 300mm C~1pF/cm • “Standard detector today” for HEP experiments (HERA (all), Belle, LEP, Tevatron) • pitch 25 – few hundred microns • readout strips in p+ side (for SSD) or both sides (for DSD) - around 6 cm long AC/DC coupled • 300 mm thick produced on n type-standard float zone silicon • n-type silicon of 2-15 kWcm resistivity • poly-silicon or FOXFET biased on the readout side • Multi guarding structure • Physics reasons: • superior position resolution (up to few microns), due to fine segmentation • fast charge collection (tcol~ few ns) for 300 mm thick sensors – high rate operation • dE/dx possible • operational at moderate voltages G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  7. LHC & SLHC G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  8. LHC – new challenge LHC properties • Proton-proton collider, 2 x 7 TeV • Luminosity: 1034 • Bunch crossing: every 25 nsec, Rate: 40 MHz • event rate: 109/sec (23 interactions per bunch crossing) • Annual operational period: 107 sec • Expected total op. period: 10 years • Main problems of a tracker at LHC: • Loss of efficiency • fast electronics (high series noise) • charge trapping (loss of signal) • high Ubias , danger of break-down • High power dissipation (8W/module for ATLAS-SCT) • Need for running cool (leakage current) • Need for storing cool to reduce Vfdincrease • Large scale – complex services and links G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  9. CMS Overall length: 21.5m, diameter: 15m, total weight: 12500t, magnetic field: 4T ATLAS Overall length: 46m, diameter: 22m, total weight: 7000t, magnetic field: 2T G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  10. 5 years 10 years 2500 fb-1 500 fb-1 Q>4000e Inner Pixel Q>9000e Q>18000e Mid-Radius Short Strips Outer-Radius “SCT” Super LHC • LHC upgradeLHC (2007),L = 1034cm-2s-1f(r=4cm) ~3·1015cm-2 • Super-LHC (2015 ?),L = 1035cm-2s-1f(r=4cm) ~1.6·1016cm-2TID=4 MGy ~5000e CERN-RD48 CERN-RD50 Phase 1: no major change in LHC L = 2.34 ∙1034cm-2s-1(higher beam current)Phase 2: major changes in LHC L = 4.6 ∙1034cm-2s-1with (BL/2, qc) L = 9.2 ∙1034cm-2s-1 with (fill all bunches) Phase 3: increase beam energy to 14 TeV (9 to 17 T magnets) • Two main problems: • Occupancy increase • Radiation damage G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  11. ID requires complete replacement, but keeping services at the same level! Long barrel proposal (other “Straw Man” design) ID ATLAS @ LHC ID ATLAS @ SLHC Time plan: R&D 2009, 2010 Construction phase, 2014 Commissioning ATLAS at SLHC(II) Initial studies show that other sub-detectors can be kept with small modifications and some with somewhat degraded performance also at SLHC! G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  12. ATLAS at SLHC (III) • Simulation studies done to determine optimum segmentation to cope with high track multiplicities: • 230 min. bias collisions/BC • 10000 tracks for |h|<2.3 Long strips 12 cm x 80 mm Short strips 3 cm x 50 mm LHC x10 if BCT=25 ns x5 if BCT=12.5 ns Pixels 400x50 mm2 SLHC G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  13. Radiation damage in semiconductor detectors G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  14. The CERN RD50 Collaboration http://www.cern.ch/rd50 RD50: Development of Radiation Hard Semiconductor Devices for High Luminosity Colliders • formed in November 2001 • approved as RD50 by CERN June 2002 • Main objective: Development of ultra-radiation hard semiconductor detectors for the luminosity upgrade of the LHC to 1035 cm-2s-1 (“Super-LHC”). Challenges: - Radiation hardness up to 1016 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!) Presently 260 members from 53 institutes Belarus (Minsk), Belgium (Louvain), Canada (Montreal), Czech Republic (Prague (3x)), Finland (Helsinki, Lappeenranta), Germany (Berlin, Dortmund, Erfurt, Freiburg, Hamburg, Karlsruhe, Munich), Israel (Tel Aviv), Italy (Bari, Bologna, Florence, Padova, Perugia, Pisa, Trento, Turin), Lithuania (Vilnius), 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(Exeter, Glasgow, Lancaster, Liverpool, Oxford, Sheffield, Surrey), USA (Fermilab, Purdue University, Rochester University, SCIPP Santa Cruz, Syracuse University, BNL, University of New Mexico) G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  15. Radiation damage Two types of radiation damage in detector materials: Bulk (Crystal) damage due to Non Ionizing Energy Loss (NIEL) - displacement damage, built up of crystal defects – I. Increase of leakage current (increase of shot noise, thermal runaway) II. Change of effective doping concentration(higher depletion voltage, under- depletion) III. Increase of charge carrier trapping(loss of charge) Surface damage due to Ionizing Energy Loss (IEL)- accumulation of charge in the oxide (SiO2) and Si/SiO2 interface – affects: interstrip capacitance (noise factor), breakdown behavior, … ! Signal/noise ratio = most important quantity ! G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  16. Frenkel pair V Vacancy + Interstitial Si I particle s EK > 25 eV EK > 5 keV Point Defects (V-V, V-O .. ) clusters Influence of defects on the material and device properties Trapping (e and h) CCEshallow defects do not contribute at room temperature due to fast detrapping charged defects Neff , Vdepe.g. donors in upper and acceptors in lower half of band gap generation leakage currentLevels close to midgap most effective G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  17. Main Selection Parameters Main Operative Characteristics Main Material Characteristics Selecting rad-hard materials fortracker detectorsat SLHC  High CCE High crystalline quality & negligible rad-induced deep traps Negligible trapping effects High E field close r-o elect.  Lownoise Low leakage current No type inversion Low dielectric constant  Lowpower big bandgap Thin thickness  High speed Low full depletion voltage High resistivity High mobility & saturation field but: higher e-h creation energy Cost-effective but: higher capacitance Commercially available in large scale G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  18. New Materials: Diamond, SiC, GaN • Wide band gap (3.3eV) • lower leakage current than silicon • Signal:Diamond 36 e/mmSiC 51 e/mmSi 80 e/mm • more charge than diamond • Higher displacement threshold than silicon • radiation harder than silicon (?) R&D on diamond detectors: RD42 – Collaborationhttp://cern.ch/rd42/ CCE at high fluences degrades even more in SiC and GaN than in Si. G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  19. Approaches to develop radiation harder tracking detectors • Material engineering • Device engineering • Change of detector • operational conditions • 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 Si • Pre-irradiated Si • Influence of processing technology • Device Engineering (New Detector Designs) • p-type silicon detectors (n-in-p) • thin detectors • 3D and Semi 3D detectors • Stripixels • Cost effective detectors • Simulation of highly irradiated detectors • Monolithic devices CERN RD39“Cryogenic Tracking Detectors” G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  20. Change of Depletion Voltage Vdep(n-type material – RD48 results) …. with time (annealing): …. with particle fluence • Short term: “Beneficial annealing”• Long term: “Reverse annealing” - time constant depends on temperature:~ 500 years (-10°C)~ 500 days ( 20°C)~ 21 hours ( 60°C) - Consequence: Detectors must be cooled even when the experiment is not running! •“Type inversion”: Neff changes from positive to negative (Space Charge Sign Inversion) p+ p+ n+ n+ after inversion neglecting double junction before inversion G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  21. The role of the oxygen in the Si (Vfd (I)) MCz-n Helsinki • For detectors irradiated with charged hadrons • RD50: High initial oxygen dimmer(O2i) MCz/Czand Epitaxial silicondetectors • positive space charge (Bi-stable donors) Increase of Vfd at high fluences is roughly the same in all O rich materials |Neff|~7·10-3 cm-1 Fp ! • Almost independent of oxygen content: • Donor removal • “Cluster damage”  negative charge After neutron irradiation all materials behave similarly and neutrons are 3x (except epi-Si) more damaging than charged hadrons! • In FZ detectors irradiation introduces effectively negative space charge! • For detectors irradiated with charged hadrons • RD48: Higher oxygen content less negative space charge G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  22. Proton irradiated oxygen rich detectors (Vfd(II)) 500 V End of LHC 300 mm thick sensors Do we undergo SCSI NO verified by TCT & annealing curves beneficial and reverse annealing similar to that of n-type STFZ, DOFZ materials • Positive space charge is compensated by negative formed during RA • Reverse annealing time constants are prolonged by high concentration of O G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  23. Thin n-type epitaxial Si detectors-CERN-scenario experiment(Vfd(III)) S-LHC: L=1035cm-2s-1Most inner pixel layer • Parameters extracted at elevated annealing fit measurements at room temperatures very well • Very good reproducibility and working model (BA, constant damage, 1st order RA, 2nd order RA) operational period per year:100 d, -7°C, Φ = 3.48·1015cm-2beam off period per year 265 d, +20°C G. Lindström et al. positive stable damage negative space charge during RA Compensation The scenario can be found where the Neff can be controlled. Increase of Vfd is not a limiting factor for efficient use of Si detectors! G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  24. Neutron irradiated epitaxial Si detectors (Vfd(IV)) neutrons no SCSI n-type detectors SCSI G. Kramberger et al., 8th RD50 workshop SMART coll., 8th RD50 workshop Neutrons: smaller increase of |Neff| with fluence than in any other material |gc|~5·10-3 cm-1 no SCSI for r=50 Wcm ; SCSI for r>150 Wcm 20<r<60 cm 200 mm , Fmax=2∙1015 cm-2Vfd < 300 V Not easy to produce G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  25. Remember we have a mixture of pions and neutrons in experiments! extrapolated values r~4cm r~20cm r~60cm electrons for higher fluences holes Trapping of the drifting charge (I) • The be,h was so far found independent on material; • resistivity • [O], [C] • type (p,n) • wafer production (FZ, Cz, epitaxial) • somewhat lower trapping at Feq>1015 cm-2 G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  26. Confirmed also by ATLAS pixel test beam! T. Lari, Nucl. Inst. Meth. A518 (2004) 349. Trapping of the drifting charge (II) Trapping probability decreases with temperature, but mobility also! Operation at lower T doesn’t improve CCE ! G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  27. with time (annealing): 80 min 60C Leakage current …. with particle fluence: • Leakage current decreasing in time (depending on temperature) • Strong temperature dependence: • Damage parameter  (slope in figure)Leakage current per unit volume and particle fluence •  is constant over several orders of fluenceand independent of impurity concentration in Si can be used forfluence measurement Consequence:Cool detectors during operation! Example: I(-10°C) ~1/16 I(20°C) G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  28. Device engineering G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  29. segmentation Device engineering - Signal in Si detectors (I) p+ Weighting field hole sensing electrode all other electrodes 280 mm electron n+ n+ Contribution of drifting carriers to the total induced charge depends on DUw ! Uw simple in diodes and complicated in segmented devices! For track: Qe/(Qe+Qh)=19% in ATLAS strip detector diode Qh=Qe=0.5 q 80 mm pitch 18 mm implant G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  30. Device engineering - Signal in Si detectors (II) drift current scalar field in which the carrier drifts Terms different for holes and electrons • trapping term ( teff,e~teff,h) • drift velocity ( me~3mh) electrons get less trapped example of inverted p+-n 280 mmfully depleted detector with 25 mm pitch G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  31. Device engineering - Signal in Si detectors (III) p+ n+ Segmented readout Segmented readout diode worse  good  better  even worse: p+ readout (p+-n detector) even better: n+ readout (n+-p, n+-n detector) How to get maximum signal? • use of n+-n or n+-p device (electron collection) with pitch<<thickness • implant width close to pitch (depends on FE elec. – inter-electrode capacitance) • for a given cell size of a pixel detector G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  32. Device engineering - Signal in Si detectors (IV) p+ p+ n+ n+ Segmented readout Segmented readout electrons Carriers in this region would be trapped before reaching high Ew! It doesn’t matter if the region is depleted or not - under-depleted detectors would perform almost as good as fully depleted! G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  33. measuring p+ p bulk n+ ±U Device engineeringTrapping induced charge sharing Incomplete charge collection due to trapping results in appearance of the charge in the neighboring strips! bipolar pulse n+ strips (higher signal) diode p+ strips (wider cluster) 0 81% Signals in the neighbors few % of the hit strip Depends strongly on fluence position of the hit and electrode geometry! observed in atlas test beam Y. Unno et al., IEEE Trans. NS 49(4) (2002) 1868 G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  34. strip 1 strip 2 oxide + + + + + + + + n+ n+ p- substrate electron layer p+ backplane S1 S1 S2 S2 S1 S2 Device engineeringIsolation techniques n+-side readout (I) isolation structure needed to interrupt the inversion layer between the strip 3 techniques available (from n+-on-n technology): p-stop p-spray/p-stop p-spray high-field region depends on Qox high-field regions high-field regions  Cint, VBR degrade with radiation (Oox), better initially Cint, VBR improve with radiation (Oox), worse initially compromise Simulations needed for each design of a detector to find an optimum! G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  35. Silicon detectors for SLHC G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  36. n+-p short strip detectors (20<r<60 cm) Detector geometry: Thickness=300 mm, strip pitch=80 mm, implant width= 18 mm, LHC speed readout (SCT128A-HC), beta source measurements n-in-p : standard FZ • ~40% charge loss after 3x1015 p/cm2 (23 GeV) • ~7000 e after 7.5x1015 p/cm2 (23 GeV) p-in-n : oxygenated and standard FZ • 25% charge loss after 5x1014 p/cm2 (23 GeV) • over-depletion is needed Vfd Vfd~1200 V CCE~60% Vfd>2500 V CCE~30% P.P. Allport et al., IEEE Trans. NS 52(5) (2005) 1903. Much better performance (same charge 6x the fluence + under-depleted operation) G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  37. n+-p short strip detectors (20<r<60 cm) recent neutron irradiated samples T=-20oC, Vbias=900 V Trapping times tend to longer than predicted at high fluences! • At first unexpected behavior of CCE(t) • Possible explanation: • Increase of Vfd(not so important as electric field is still present close to electrodes) • Annealing of electron trapping times CONFIRMED also by simulations! The reverse annealing is not critical as for LHC! G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  38. n+-p short strip detectors – super modules LBNL proposal (evolved from CDF run IIb) Liverpool proposal Bridging structure TPG baseboard G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  39. n+-p short strip detectors – shot noise STFZ detectors Short strips at r=35 cm (3 cm x50 mm) P. Allport et al. CR-RC shaping Short strips should have noise below 1000 e – dominated by series noise 25 ns shaping time In order to keep the noise below the desired limit ENCleak<500e , T<-15oC G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  40. Long strip detectors (r>60 cm) • Present technology (STFZ p+-n) pushed to the higher radii may work – however practical issues cold/warm during the beam-off must be considered • Better would be n+-p type detectors (regardless of the silicon type – neutron dominated damage) • higher signal and possible use potentially of longer strips to reduce # of channels and have the same S/N • No ballistic deficit with BCT=12.5 ns • Smaller operational voltage needed and no critical issue if Vfd>operational bias (safety) G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  41. Planar n+-p pixel detectors (r<20 cm) • Pion dominated damage – choice of material for these detectors MCz or epi-Si! • Detectors of some 200 mm almost ideal choice if kept warm during beam-off period • Compensation of positive space charge with acceptors during RA (always fully depleted) • Annealing of electron trapping times – smaller effect of trapping • Smaller power dissipation due to smaller leakage current and bias voltage • Smaller shot noise Epi-Si,75 mm n. irr diodes • after annealing (reduction of Vfd and electron trapping times) • after segmentation (higher contribution of electrons) ~4000e@1016cm-2 G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  42. 10 years of LHC (4 cm) at 1034 cm-2 s-1 10 years of SLHC (4 cm) 1034 cm-2 s-1 Threshold needed on pixel FE electronics is for ATLAS and CMS pixels around 3500-4000 electrons! Can we hope for better electronics? (60,100,160V) (500V) more charge at lower voltages (<300 V) with epi-Si (600 V) G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  43. 3D n+-p pixel detectors (r<20 cm) Combine traditional VLSI processing and MEMS (Micro Electro Mechanical Systems) technology. Both electrode types are processed inside the detector bulk instead of being implanted on the wafer's surface. The edge is an electrode. Dead volume at the Edge < 5 microns! Essential for forward physics experiments and material budget S.I. Parker, C.J. Kenny, J. Segal, Nucl. Instr. and Meth. A395 (1997) 328. G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  44. 3D n+-p pixel detectors (r<20 cm) • Cons. • Columns are dead area (aspect ratio ~30:1) • Spatially non-homogenous CCE (efficiency=function of position) • Much higher electrode capacitance (hence noise), particularly if small spacing is desired – small drift length • Availability on large scale • Time-scale and cost • Pros. • Better charge collection efficiency • Faster charge collection (depends on inter-column spacing) • Reduced full depletion voltage and by that the power • Larger freedom for choosing electrode configuration G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  45. Volume = 1.2 x 1.33 x 0.23 mm3 • 3 electrode Atlas pixel geometry • n-electrode readout • n-type before irradiation - 12 kWcm • Irradiated with neutrons G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  46. ionizing particle cross-section between two electrodes n+ n+ holes drift in the central region and diffuse towards p+ Contact (long tail) electrons are swept away by the transversal field Different geometry – 3D sct (RD50) C. Piemonte et al., IRST Functioning: Sketch of the detector: n-columns p-type substrate grid-like bulk contact G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  47. Different geometry – 3D sct 3D-stc DC coupled detector (64 x 10 columns) 80 mm pitch 80 mm between holes 10 mm hole diameter Inter-column region depleted @ 12 V 150 mm 300 or 500 mm undepleted Diode like structure CCE measurements (slow shaping time) Focused IR laser of 7 mm spot size 3 strips connected to amplifier Thickness calculated from signal G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  48. Different geometry – 3D dct 1um Passivation Metal • Designed proposed by RD50 collaboration (IRST, CNM, Glasgow) • much simplified process – no need for support wafer during production • single sided processing with additional step of etching and B diffusion • Performance equal to original design 0.4um Oxide 5mm P-stop p+ 50mm n+ doped 10mm TEOS 2um 300mm Poly 3mm p- type substrate p+ doped p+ doped 50mm Oxide Metal 55um pitch G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  49. Electronics – deep sub micron CMOS (ATLAS pixel, CMS all) G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

  50. Electronics – BiCMOS • Short shaping times (12.5 ns) • large capacitances Bipolar transistors perform better in terms of noise-power (CMOS requires larger bias current) BiCMOS in atlas not radiation hard enough and not available anymore Bipolar SiGe transistors “married” to DSM-CMOS Around 4 times smaller power consumption than present design G. Kramberger, Jožef Stefan Institute, Towards Radiation Hard Silicon Detectros at SLHC

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