1. 19th February, VCI 2007 Paula Collins, CERN 1 Semiconductor Vertex Detectors for High Luminosity Environments  The Dawn of Vertexing  e + e - colliders  Through Tevatron, towards LHC  The Golden Age  some villains  and some heroes  Super Heroes of the future  The Rise and Rise of pixels: MAPs, DEPFETs, CCDs, 3d detectors, SOI…  Rad Hard(er) Devices: Novel materials, device engineering… Paula Collins, CERN

2. 19th February, VCI 2007 Paula Collins, CERN 2 Alternatively… SLHC To Infinity and Beyond! Who will be the true superhero of the SLHC era?

3. 19th February, VCI 2007 Paula Collins, CERN 3 Alternatively…. How do I cope with having 10 quadrillion particles thrown at me?* *10 16 fluence / cm 2 at 4cm SLHC

4. 19th February, VCI 2007 Paula Collins, CERN 4 The LEP era Singapore Conference, 1990 ‘The LEP experiments are beginning to reconstruct B mesons… It will be interesting to see whether they will be able to use these events’ Gittleman, Heavy Flavour Review 10 fun packed years later, heavy flavour physics represented 40% of LEP publications

5. 19th February, VCI 2007 Paula Collins, CERN 5 and more… Reconstructed B-mesons in the DELPHI microvertex detector  semiconductor vertex detectors used for  vertexing  flavour tagging, lifetimes..  help in tracking  triggering  even dE/dx…  used at all current HEP collider experiments  exploits great precision and small beampipes Primary Vertex B hadron Vertex  B  1.6 ps l = c   500  m 

6. 19th February, VCI 2007 Paula Collins, CERN 6 Challenge of the LHC n eq /cm 2 per year LHCb radius [cm] at full luminosity L=10 34 cm -2 s -1 :  ~23 overlapping interactions in each bunch crossing every 25 ns ( = 40 MHz )  inside tracker acceptance (|  |<2.5) 750 charged tracks per bunch crossing  per year: ~5x10 14 bb; ~10 14 tt; ~20,000 higgs; but also ~10 16 inelastic collisions – impact parameter resolution important  severe radiation damage to detectors:  Fast Hadron dose at 4 cm after 10 years/500 fb -1 is 3 x 10 15 cm -2  Fast Hadron Dose at 22 cm after 10 years/ 500 fb -1 is 1.5 x 10 14 cm -2  detector requirements: speed, granularity, radiation hardness ATLAS

7. 19th February, VCI 2007 Paula Collins, CERN 7 What of the future? The problems pile up…..

8. 19th February, VCI 2007 Paula Collins, CERN 8 SLHC environment  Integrated Luminosity 2500 fb -1 = 5 x LHC  dictates technology choice  Peak luminosity 10 35 cm -2 s -1 = 10 x LHC  dictates detector granularity  Scenarios dominated by 50ns or 25 ns running  Detector R&D focused on  short term replacement/upgrades e.g. replacement of ATLAS b layer after 2-3 years (10 15 n eq ), CMS Phase 1 pixel replacement, replacement of LHCb VELO …  SLHC upgrades (major changes expected to modules and electronics SLHC fluences R=20cm, 1 10 15 cm -2 30 MRad, charged hadrons 50% R=4cm, 1.6 10 16 cm -2 400 MRad, charged hadrons 100% R=75cm, 1.5 10 14 cm -2 3.5 MRad, charged hadrons 20% Phase 1: no major change in LHC L = 2.34 ∙10 34 cm -2 s -1 (higher beam current) Phase 2: major changes in LHC L = 4.6 ∙10 34 cm -2 s -1 with (BL/2,  c ) L = 9.2 ∙10 34 cm -2 s -1 with (fill all bunches) Phase 3: increase beam energy to 14 TeV (9 to 17 T magnets) Mika Huhtinen

9. 19th February, VCI 2007 Paula Collins, CERN 9 Point defects + clusters Dominated by clusters Non Ionizing Energy Loss NIEL: displacement damage A common language: “1 MeV neutron equivalent” Use the NIEL scaling factors NIEL allows us to look into the future and predict what will happen in complex environments (!) Is known to fail for neutrons/charged hadrons in some cases

10. 19th February, VCI 2007 Paula Collins, CERN 10 Radiation Damage: Traditional Villains Increased Leakage Current  Noise  Hard to bias  strong temperature dependence – cooling essential e.g. I(-10 o C)=1/16 I(20 o C)  anneals with time and temperature  I/V=  *  , the damage parameter, very consistent for a wide range of impurities and silicon types Effective Doping Changes  negative space charge builds up, depletion voltage changes  Junction moves from p+ to n+ side Depletion voltage [V] Fluence Annealing effects  Buildup of negative space charge worsening in time  Strongly temperature dependent: 500 years @ -10 o C = 21 hours at 60 o C! Depletion voltage [V] time [years]

11. 19th February, VCI 2007 Paula Collins, CERN 11 Trapping is characterized by an effective trapping time  eff for e - and h: Increase of 1/  with fluence1/  changes with annealing where Huge Decrease in CCE? New Villain: trapping

12. 19th February, VCI 2007 Paula Collins, CERN 12  = 6x10 14 n/cm 2 Charge collection measured using cluster profiles in a row of pixels illuminated by a 15º beam and no magnetic field after type inversion N eff =N D - N A <0 - Model with constant space charge density does not describe the measured charge collection Radiation Damage: Is N eff really so bad? V. Chiochia et.al. IEEE Trans. Nucl. Sci 52 (2005) 1067

13. 19th February, VCI 2007 Paula Collins, CERN 13 E A/D = trap energy level fixed N A/D = trap densities from fit  e/h = trapping cross sections from fit  1 =6x10 14 n/cm 2, N A /N D =0.40,  h /  e =0.25  Data --- Simulation  Data --- Simulation V.Chiochia, Vertex 05 n+-p junctionn-p+ junction E Two trap model

14. 19th February, VCI 2007 Paula Collins, CERN 14 Radiation damage as experienced in running HEP experiments NA60 first use of pixels in high multiplicity experiment dimuon production by 158 gev indium ions 16 planes of silicon pixel detectors 12.8 x 13.6 mm2 active area 32 x 256 cell matrix 50 x 425 um2 cell size ALICE 1LHCb readout chips ATLAS faster pixels radiation damage type inversion after 4 weeks running 4x10 12 ions on target ~10 13 neutrons equivalent

15. 19th February, VCI 2007 Paula Collins, CERN 15 Irradiation at CDF/D0 Ignacio Redondo, CMS workshop, 20 th October 2006  2 fb -1 data collected (goal = 5-8fb - 1 )  L00 (1.4cm) SVXII (2.5-10.6cm), ISL  Ionising dose measured with TLDs  3cm z<45cm: 300 +- 60 kRad/fb-1  scales as 1/r  (1.5 < a < 2.1)  L00 2 MRad, SVX layer 0 800 kRad  Measured depletion voltages both with signal and noise methods L0 depletion Voltage

16. 19th February, VCI 2007 Paula Collins, CERN 16 tackling the villains Defect Engineering  Oxygen enriched silicon  Cz silicon  … New Sensor Materials  Silicon Carbide  Amorphous silicon  Compound semiconductors  Diamond Device Engineering  p-type silicon detectors  thin detectors  3D  Monolithic devices  DEPFETS  MAPS  CCDs with on situ storage  SOI … Operational conditions  Cryogenic operation 3D silicon stacks -> see talk of Toru Tsuboyama -> see talk of W. Dulinkski -> see talk of J. Mnich + posters of Bamberger, Traversi, Gabrielli, Servoli, Luuka, See talk of S. Eckert

17. 19th February, VCI 2007 Paula Collins, CERN 17 new kid on the block: p-type substrate  n-on-n already preferred option for ATLAS, CMS, and LHCb  Faster charge collection  underdepleted operation an option  After type inversion n-on-n effectively becomes p-on-n: Why not start with step p type substrates Efficiency ATLAS NIM A 450 (2000) 297 ATLAS n sidep side V bias LHC b V bias NIM A 440 (2000) 17 LHCb p siden side Resolution [  m] V bias Reminder: figure shown at VCI 2001 – silicon experts learn about weighting field!!

18. 19th February, VCI 2007 Paula Collins, CERN 18 p type continued  Advantages of p-type  high field region always on the strip side – no need for (expensive) double sided processing  easier handling  proven radiation hardness  collect electrons – slightly less susceptible to trapping after neutron irradiation  indication of good annealing behaviour (as measured with CCE) cooling, handling  Effort going into characterising strip isolation methods (as for n-in-n)  RD50 collaboration with CNM, Micron  FZ, DOFZ, MCz silicon  pads, strips, pixels  p-stop, p-spray  Many groups: Liverpool, IFIC, KEK, INFN.. S1S2S1S2S1S2 p-spray p-stop p-spray/p-stop high-field regions high-field region depends on Q ox C int, V BR improve with radiation (O ox ), worse initially C int, V BR degrade with radiation (O ox ), better initially compromise

19. 19th February, VCI 2007 Paula Collins, CERN 19 p type; irradiation of short strip devices V fd >2500 V V fd ~1200 V V fd P.P. Allport et al., IEEE Trans. NS 52(5) (2005) 1903. Detector geometry: Thickness=300  m, strip pitch=80  m, implant width= 18  m, LHC speed readout (SCT128A-HC), beta source measurements n-in-p : standard FZ  ~40% charge loss after 3x10 15 p/cm 2 (23 GeV)  ~7000 e after 7.5x10 15 p/cm 2 (23 GeV) Performance superior to p-on-n (n-on-n unknown at these fluences) Annealing behaviour w.r.t. CCE spectacular n-in-p : annealing  3 x 10 15 n/cm 2  V dep ~ 1200 V G. Casse, this conference 0.7x10 15 1.9x10 15 4.7x10 15 10x10 15 M Lozano, this conference

20. 19th February, VCI 2007 Paula Collins, CERN 20 p type continued  Full scale sensors manufactured for LHCb and placed in final detector layout in test beam  8.4 cm diameter sensors  strip pitch 40-100  m  excellent leakage currents  fraction of bad strips < 1%  preliminary results show pre- irradiation performance very comparable to n-in-n – technology feasibility demonstrated T. Bowcock

21. 19th February, VCI 2007 Paula Collins, CERN 21 Oxygen lessons from LHC Based on RD48 discovery that V fd varies more slowly for oxygenated sensors, DOFZ chosen for detectors in most irradiated regions of ATLAS,CMS,LHCb However, note that neutron irradiation is 3xmore damaging and constant for all materials… Epitaxial silicon  Chemical-Vapor Deposition (CVD) of Silicon  CZ silicon substrate used  diffusion of oxygen  Growth rate about 1  m/min  Excellent homogeneity of resistivity  150  m thick layers produced (thicker is possible)  price depending on thickness of epi-layer but not extending ~ 3 x price of FZ wafer try materials naturally rich in Oxygen Czochralski silicon  Pull Si-crystal from a Si-melt contained in a silica crucible while rotating.  Silica crucible is dissolving oxygen into the melt  high concentration of O in CZ  Material used by IC industry (cheap), now available in high purity for use as particle detector (MCz)

22. 19th February, VCI 2007 Paula Collins, CERN 22 Cz: high homogeneous concentration and formation of Thermal Donors (reducing acceptors due to radiation) Epitaxial silicon  EPI: inhomogeneous O concentration due to diffusion from substrate into epi-layer during production [G.Lindström et al.,10 th European Symposium on Semiconductor Detectors, 12-16 June 2005]  DOFZ: inhomogeneous oxygen distribution, increasing with time at high temperature EPI layer CZ substrate Oxygen concentration in FZ, Cz, and EPI

23. 19th February, VCI 2007 Paula Collins, CERN 23 Cz FZ DOFZ MCz silicon MCz-n Helsinki irradiation with charged hadrons Annealing behaviour  Gradient of slope after minimum (  ) is smaller for MCz than for FZ for 10 MeV, 50 MeV and 24 GeV proton irradiation  The effective trap introduction rate for both electrons and holes is similar for MCz, FZ, and DOFZ silicon  Leakage current behaviour is also similar Many groups studying Cz, MCz: INFN, Glasgow, BNL, HIP, Purdue, Liverpool, Rochester… G. Pellegrini et. al “Annealing Studies of magnetic Czochralski silicon radiation detectors” E. Tuovinen et. al. 4 th RD50 workshop

24. 19th February, VCI 2007 Paula Collins, CERN 24 MCz TCT measurements  TCT measurements confirm that after irradiation with charged hadrons the material does not type invert  the trap introduction rate for holes and electrons is similar for FZ, DOFZ and MCz silicon  This behaviour can be understood qualitatively as a build up of donors, which overcompensates the (classical) introduction of acceptors 1414 Time [ns] Low field High field 5x10 14 p/cm 2 High field Low field hole collection electron collection A. Bates, VERTEX 04

25. 19th February, VCI 2007 Paula Collins, CERN 25 MCz TCT measurements continued  Irradiation with neutrons shows a more complex picture  High field region on n+ side implies type inversion  In this respect MCz and FZ behave similarly Φ (10 14 n*cm -2 ) p+p+ n+n+ E1E1 EbEb E2E2 W1W1 WbWb W2W2 h 1 B 2  1 MeV, = 5 ×10 14 cm -2 CZ n-Si, E(x) is non-uniform in these sensors (as in other, non MCz, heavily irradiated structures) Consider 3 regions: N eff >0, electrically neutral, N eff <0 reverse current flow induces electric field in electrically neutral base For detector performance, V dep is an “abstract concept” More important to consider CCE, charge collection time etc. Verbitskya et.al. NIM A 557 (2006) 528 [D. Menichelli, RD50 Workshop, Nov..2005] p+ n+

26. 19th February, VCI 2007 Paula Collins, CERN 26 MCz CCE p type MCz Si diodes, proton irradiated AC coupled r/o shaping time 2.4us At overdepletion 90% CCE for 6.8 x 10 14 n eq p-on-n MCz microstrip device, 200 ns shaping time proton irradiated 90% CCE achieved at 500V for 3.3 x 10 14 n eq m bruzzi et al, hiroshima symposium 2006 Simulation predicts for 300 and 200 um thick a S/N of 10 at 3 x 10 15 which would be adequate for operation of a detector Sadrozinski STD07

27. 19th February, VCI 2007 Paula Collins, CERN 27 Neutron irradiation: excellent peformance of Neff evolution; no SCSI for 50  m sample CCE measured with mips : 3200 electrons after 8 x 10 14 n eq / cm 2 Superrad hard : Fledermaus-man? (performs best in superhero mode…) G. Kramberger et al., 8th RD50 workshop SMART coll., 8th RD50 workshop neutron irradiation EPI silicon G. Lindström et al. Kramberger et al 8 th RD50 workshop June 2006

28. 19th February, VCI 2007 Paula Collins, CERN 28 EPI silicon : annealing behaviour With cooling when not operated Without cooling when not operated  Annealing behaviour shows drop of Vdep in time Using the LHC operation model:  eq(year) = 3.5  10 15 cm -2  Radiation @ 4cm:  eq(year) = 3.5  10 15 cm -2  SLHC-scenario:  1 year = 100 days beam (-7  C)  30 days maintenance (20  C)  235 days no beam (-7  C or 20  C)  Operation without cooling is beneficial!!! G.Lindström et al.,10 th European Symposium on Semiconductor Detectors, 12-16 June 2005 (Damage projection: M.Moll) Kramberger et al 8 th RD50 workshop June 2006

29. 19th February, VCI 2007 Paula Collins, CERN 29 Diamond  large band gap and strong atomic bonds give fantastic radiation hardness  low leakage current and low capacitance both give low noise  3 (1.5) times better mobility and 2x better saturation velocity give fast signal collection  Ionization energy is high: MIP  2x less signal for same X 0 (w.r.t. SI)  Diamond:  13.9ke - in 361  m  SI:  26.800 ke - in 282  m  In Polycrystalline Diamond grain- boundaries, dislocations, and defects:  limits carrier lifetime, mobility and charge collection distance and position resolution Polycrystalline Diamonds traditionally grown by CVD growth substrate Grain size: ~100-150μm Diamond as detector material now well established with BCM as first large scale (HEP) application Detector application (pixel, strip, pad) demonstrated

30. 19th February, VCI 2007 Paula Collins, CERN 30 Radiation Hardness of pCVD diamond  pCVD charge collection distances of 250-300  m now routinely achieved  charge collection distance saturates at 1V/  m  pCVD detectors have been built as pixel, pad, strip detectors  Proton irradiation of strip detectors to 2.2x10 15 /cm 2 :  15% loss of S/N at 2.2x10 15 /cm 2  Decrease of leakage current ( ~ pA)  Improvement of resolution by ~ 35% - irradiated material is more “ uniform ”  Proton irradiation to 1.8 x 10 16 /cm 2  75% loss of signal  S/N performance > 10

31. 19th February, VCI 2007 Paula Collins, CERN 31 Single crystal diamond has been fabricated with Element six ≈ 10 mm × 10mm, >1 mm thickness. Largest scCVD diamond ≈ 14 mm × 14 mm. Single Crystal Diamond Excellent mobility. For this sample: µ 0h = 1714 cm 2 /Vs, µ 0e = 2064 cm 2 /Vs High drift velocity  better lifetimes  charge trapping might not be an issue Most probable charge versus thickness  High quality scCVD diamond can collect full charge at 0.2 V/um  Width of Landau distribution is ≈ 1/2 that of silicon, ≈ 1/3 that of pCVD diamond  radiation hardness under study d=320 μm Q MP =9500e-

32. 19th February, VCI 2007 Paula Collins, CERN 32 Irradiation: 3d detectors  Maximum drift and depletion distance governed by electrode spacing  Lower depletion voltages  Radiation hardness  Fast response  same technology: dope edges of sensor for edgeless detection efficiency  At the price of more complex processing  Narrow dead regions at wells Proposed by Parker, Kenney 1995 Unit cell defined by e.g. hexagonal array of electrodes Planar Device 3D Device

33. 19th February, VCI 2007 Paula Collins, CERN 33 How do we make the holes? (not like this) p n p n

34. 19th February, VCI 2007 Paula Collins, CERN 34 1) ETCHING THE ELECTRODES WAFER BONDING (mechanical stability) Si-OH + HO-Si -> Si-O-Si + H 2 O DEEP REACTIVE ION ETCHING (electrodes definition) Bosh process SiF 4 (gas) +C 4 F 8 (teflon) IR picture of 2 bonded wafers C shaped test structure ~1  m difference between top and bottom 290  m D d LOW PRESSURE CHEMICAL VAPOR DEPOSITION (Electrodes filling with conformal doped polysilicon) 2P 2 O 5 +5 Si-> 4P + 5 SiO 2 2B 2 O 3 +3Si -> 4 B +3 SiO 2 Aspect ratio: D:d = 11:1 2) FILLING THE ELECTRODES METAL DEPOSITION Shorting electrodes of the same type with Al for strip electronics readout or deposit metal for bump-bonding Non Standard Processing: Wafer bonding, Deep reactive ion etching, Low pressure chemical vapor deposition, Metal deposition  Mass production expensive 3d detector processing

35. 19th February, VCI 2007 Paula Collins, CERN 35 3d detectors: characteristics v Aug 2006, H8 CERN beam line 100 GeV/c pions 4000 e threshold 40V depletion Efficiency measured in testbeam 98% rise time seen on oscilloscope Institutes: Stanford Brunel/Manchester Hawaii/LBL New Mexico Glasgow Freiburg Bonn Praha Genova Oslo +++

36. 19th February, VCI 2007 Paula Collins, CERN 36 3d detectors: radiation hardness  electrode spacing 71 mm  n type before irradiation  Irradiated with reactor neutrons  signal height measured on scope Compilation plot from C. da Via M Lozano, n-on-p this conference EPI

37. 19th February, VCI 2007 Paula Collins, CERN 37 Passivation n+ doped 55um pitch 50  m 300  m p+ doped 10  m Oxide 0.4um 1um p+ doped Metal Poly 3  m Oxide Metal P-stop p+ 50  m TEOS 2um 5m5m p - type substrate Design 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 Different Geometry: 3D devices See S. Eckert talk for beautiful results

38. 19th February, VCI 2007 Paula Collins, CERN 38 What about the ILC? t t event at 350 GeV At LC: “x sections are tiny” “No radiation issues” “Triggerless operation possible” “Modest rates” Why not use a LEP detector? LC physics demands Excellent Vertexing (b,c,t) and Tracking  in a high B field  with energy flow we need to trim the X 0 !

39. 19th February, VCI 2007 Paula Collins, CERN 39 Silicon for vertexing @ the ILC  Use a silicon based pixel detector  Confine the background with a big solenoidal field  (IP) < 5  m  10  m/(p sin 3/2  )  best SLD 8  m  33  m/(p sin 3/2  )) Vertex detector characteristics point resolution 1-5  m Thickness ~ 0.1 % X 0 5 layers Inner radius ~ 1.5 cm radiation tolerance ~ 360 kRad / year Required Vertexing performance Flavour tagging: beauty + charm discriminate b from background discriminate b from c disentangle complex events  12 jets background: mainly e+/e- pair production due to beamstrahlung [C.Büssser, DESY]

40. 19th February, VCI 2007 Paula Collins, CERN 40 Train/rf pulse LEP 0.2 TeV NLC/JLCSuperconducting Linac 0.5 TeV Train length,  s0.7500.265950 Number of bunches/Train41902820 Bunch separation, ns2001.4337 Repetition rate, Hz455001005 Timing @ the ILC Time  at ILC, keep occupancy reasonable by reading out innermost layer in 50  sec

41. 19th February, VCI 2007 Paula Collins, CERN 41 Silicon Trends Basic idea Start with high resistivity silicon More elaborate ideas: n+ side strips – 2d readout Integrate routing lines on detector Floating strips for precision Stripixels: 2d readout Hybrid Pixel sensors Chip (low resistivity silicon) bump bonded to sensor Floating pixels for precision CCD: charge collected in thin layer and transferred through silicon MAPS: standard CMOS wafer Integrates all functions chip n+n+ n+n+ p DEPFET: Fully depleted sensor with integrated preamp Al strip amplifier SiO 2 /Si 3 N 4 + Vbias + + + + - - - n bulk p+p+ n+n+ chip

42. 19th February, VCI 2007 Paula Collins, CERN 42 + + + + Amplifying transistor integrated into high resistivity silicon detector Low noise operation possible at room temperature Thinning possible to 50  m 0V 15 V 0V DEPFET sensors Kemmer, Lutz, 1987 R&D for tracking ~ 2000 Image of DEPFET team R&D: pixel size, power, thinning, speed, radiation tolerance 2005: 128x64 36  mx29  m prototypes 512 x 512, and 128 x 2048 array under development

43. 19th February, VCI 2007 Paula Collins, CERN 43 Testbeam setup: 5 DEPFET planes ~ PCB ‘hybrid’ with DEPFET matrix, 2 x SWITCHER, 1 x CURO double metal matrix row gate Sources row clear Drain 1Drain 2Sources double pixel Switcher chip provides gate voltages DEPFET Matrix 64x128 pixels 36 x 28.5µm 2 Switcher chip provides clear voltages

44. 19th February, VCI 2007 Paula Collins, CERN 44 DEPFET  Ionising dose to ~1MRad without degradation in performance of pixel  HV switcher does not survive this dose  New switcher layout with rad hard technology and “stacked transistors” submitted and will be tested soon  S/N for 450  m thick sensor 110  upper limit on position resolution ~8  m (contains an estimated 7 um contribution from low energy tracks – data from CERN testbeam will improve this)  cluster sizes for inclined tracks comparable to simulation FE 55 spectrum from irradiated pixel measured at room temperature noise of 3.5 e (was 1.6 before irradiation) P Fisher et. al. Vertex 06

45. 19th February, VCI 2007 Paula Collins, CERN 45 Thinning sensor wafer handle wafer 1. implant backside on sensor wafer 2. bond wafers with SiO 2 in between 3. thin sensor side to desired thickness. 4. process DEPFETs on top side 5. etch backside up to oxide/implant Thinned diode structures: leakage current: < 1 nA/cm 2 Estimated material budget for first layer 0.11% X0: pixels, 50 mm thick, 0.05% X0 chips, 50 mm thick, 0.008% X0 perforated frame, 300 mm thick, 0.05% X0 leakage current 100pA / cm 2 active DEPFET area (~ 50µm thick) SWITCHER Steering chips CURO Readout chips Possible ILC implementation

46. 19th February, VCI 2007 Paula Collins, CERN 46 Same unique substrate for detector and electronics  No connections(e.g. bumps)  Radiation hardness (no bulk charge transfer)  Advantages of CMOS process: Easy Design/good yield/low power/Rad hard  Very small pixel sizes achieveable 1999 – R&D on CMOS MAPS 1999 – small scale prototypes 1999-2000 first beam tests 2001 – large prototypes 2005 – dedicated application specific chips Mimosa I ……..IVV …….VIII ……..IX ……X …….. XIV.. Process 0.6  m AMS 0.35  m AMS0.6  m AMS0.25 TSMC0.35  m AMS 0.25 mm TSMC 0.35 mm AMS Epi layer14  m0 (!!!)14  m 8  m14  m8  m0 # pixels64x64x464x64x41Mx77k7k16k16k Monolithic Active Pixel Sensors (MAPS)

47. 19th February, VCI 2007 Paula Collins, CERN 47 MAPS Beam Test Results MIMOSA I MIMOSA IIMIMOSA V Resolution1.4  m2.2  m1.7  m Efficiency at S/N > 599.5 %98.5 %99.3% Resolution [  m] Signal to Noise MIMOSA I MIMOSA V Two track separation 30 mm thinning possible to 50 mm R&D for high temperature operation (STAR upgrade)

48. 19th February, VCI 2007 Paula Collins, CERN 48 MAPS: Radiation Hardness Expectations at ILC (for 3 years of nominal running): -“non-ionizing” radiation: 3. 10 10 n eq /cm 2 MIMOSA I, II, V irradiated with 10 13 n/cm 2   Gain -> constant  Noise -> constant  Leakage current a moderate rise  collected charge a 50-70% of initial value (smooth decrease after 10 12 or few x 10 11 ) MIMOSA9 chip irradiated with 10 11 n/cm 2   test beam: S/N ~ 25,  > 99.9%  dose increased to 10 12 n/cm 2 with good results - “ionizing” radiation: 5.4. 10 12 e(10MeV)/cm 2 MIMOSA5 and MIMOSA9 chips irradiated at Darmstadt with 10 13 e(9.4MeV)/cm 2  test beam (MIMOSA9): S/N ~ 23,  > 99% - slight deterioration but still excellent performance michael deveaux

49. 19th February, VCI 2007 Paula Collins, CERN 49 Charged Coupled Devices - CCDs CCDs invented in 1970 – widely used in cameras, telescopes etc. Tracking applications for HEP: 1980-1985 NA32120 kpixels 1992-1995SLD120 Mpixels 1996-1998SLD upgrade307 Mpixels ILC799 Mpixels ~1000 signal electrons are collected by a combination of drift and diffusion over a ~20  m region just below surface Small pixel size – 20 x 20  m Possibility of very thin detectors Column parallel readout: serial register -> direct bump bonding to chip 10V 2V

50. 19th February, VCI 2007 Paula Collins, CERN 50  Speed up readout  5 MHz readout -> 50 MHz  Reduce clock amplitudes 10V->2V  Build with high resistivity epitaxial material  distributed busline over entire image area CCD R&D for ILC requirements 280.125 MHz/250 ms6.9125 x 22605 7614.350 MHz/50 ms3.3100 x 13151 Integrated background (kHits/train) Background (Hits/mm 2 ) Clock / readout timeCCD Size (Mpix) CCD lxw (mm x mm) Radius (mm)Layer noise ~ 60 e - CCD 55 Fe spectrum: 1MHz 2V clocks Study radiation resistance to LC doses of 100Krad ionising radiation + 5 x 10 9 neutrons  Temperature dependence

51. 19th February, VCI 2007 Paula Collins, CERN 51 CCDs: Thinning  CCD community have come up with incredible ways to lose weight!  Unsupported silicon with tensioning - lateral instabilities  Silicon thinned to epitaxial layer and glued to substrate - can reach 0.15% X 0  Carbon fibre substrates - good CTE match but instabilities  Silicon on foam substrate or sandwich core - < 0.1% X o should be possible!!! silicon carbide foam RVC foam

52. 19th February, VCI 2007 Paula Collins, CERN 52 ISIS – In-Situ Storage Image Sensor  Beam-related RF pickup is a concern for all sensors converting charge into voltage during the bunch train;  The In-situ Storage Image Sensor (ISIS) eliminates this source of EMI:  Charge collected under a photogate;  Charge is transferred to 20-pixel storage CCD in situ, 20 times during the 1 ms-long train;  Conversion to voltage and readout in the 200 ms-long quiet period after the train, RF pickup is avoided;  1 MHz column-parallel readout is sufficient ISIS1 “proof of principle” constructed at e2V

53. 19th February, VCI 2007 Paula Collins, CERN 53 Conclusions I  Silicon is not the only solution to your vertexing requirements: 1996: scintillating liquid capillaries for LHCb thanks: P. Koppenburg liquid: 1-methylnaphtalen Capture light in borosilicate capillaries self cooling system read out with APDs or HPDs But remains the dominant player SLAC expts workshop 1982

54. 19th February, VCI 2007 Paula Collins, CERN 54 Conclusions II  Devices are being tested which give excellent CCE and can be operated at room temperature after high fluences – we are almost there!  n strip technology looks very promising for all but the most inner layer  For which diamond and 3D look very good  Major developments underway for ILC  Electronics/services not touched on (see Spieler and Mnich talks)

55. 19th February, VCI 2007 Paula Collins, CERN 55 Conclusions III  N eff used to be THE bad guy  For heavily irradiated detectors other villains come into play, N eff becomes almost benign

56. 19th February, VCI 2007 Paula Collins, CERN 56 Conclusions IV  We also have to see what LHC brings…

57. 19th February, VCI 2007 Paula Collins, CERN 57 Conclusions V  Thank you for your attention MCz Alison Bates MAPS Marc Winter, Grzegorz Deptuch, Wojtek Dulinski, p type Gianluigi Casse, Marina Artuso CCD Steve Worm, Andrei Nomorotski DEPFET Marcel Trimpl Johannes Ulrici SDD Rene Bellweid, Vladimir Rykov Irradiation Sherwood Parker, Ulrich Parzefall, Richard Bates, Cinzia da Via, Angela Kok, Michael Moll, Mika Huhtinen, William Trischuk, Zheng Li Tevatron Alan Sill Overview Guy Wilkinson, Daniela Bortoletto Thanks for material to:

58. 19th February, VCI 2007 Paula Collins, CERN 58 backup slides

59. 19th February, VCI 2007 Paula Collins, CERN 59 depfets  https://wiki.lepp.cornell.edu/ilc/bin/v iew/Public/WWS/VtxProjects

60. 19th February, VCI 2007 Paula Collins, CERN 60 Properties of Diamond Sidiamond Band gap [eV]1.125.45 Electron mobility [cm 2 /Vs]14502200 Hole mobility [cm 2 /Vs]5001600 Saturation velocity [cm/s]0.8x10 7 2x10 7 Breakdown field [V/m]3x10 5 2.2x10 7 Resistivity [Ω cm]2x10 5 >10 13 Dielectric constant11.95.7 Displacement energy [eV]13-2043 e-h creation energy [eV]3.613 Ave e-h pairs per MIP per μm8936 Charge coll. dist. [μm]full~250 Low I leakage, shot noise Fast signal collection Low capacitance, noise High radiation hardness Smaller signals + high thermal conductivity: Room temperature operation CERN RD42 Collaboration: - Development of detector grade diamond - Industrial partner: Element Six, Ltd.

61. 19th February, VCI 2007 Paula Collins, CERN 61 ILC vtx comparison

62. 19th February, VCI 2007 Paula Collins, CERN 62 n+n+ n+n+ p+p+ n+n+ p+p+ n+n+ p+p+ n+n+ p+p+ 50  m Active edge 4  m

63. 19th February, VCI 2007 Paula Collins, CERN 63 MAPS 6 x 6  m 3.4 x 4.3  m 6 x 6  m 1.2 mm0.96 mm 5 x 5  m  Main features:  Self Bias / Standard  Pitch 20/30/40  m  Small/large diodes (3/6  m)  With/without epi  intended to withstand high temperatures MIMOSA 9 Noise vs temperature (Noise2 ∝ Ileak=a+b.T2exp(-Egap/2kT)) – signal independent of T promising technology for star vtx upgrade

64. 19th February, VCI 2007 Paula Collins, CERN 64 n+n+ p+p+ 500  m

65. 19th February, VCI 2007 Paula Collins, CERN 65 Silicon for tracking: Silicon Drift Detectors  Principle of sideways depletion – as for DEPFET sensors  p + segmentation on both sides of silicon  Complete depletion of wafer from segmented n + anodes on one side y x !! Drift velocity must be predictable  Temperature control  resistivity control  Calibration techniques  SDD fully functioning in STAR SVT since 2001  216 wafers, 0.7 m 2  10  m in anode direction  20  m in drift direction  Particle ID

66. 19th February, VCI 2007 Paula Collins, CERN 66 Silicon for tracking: Drift detectors  SDD are a mature technology – attractive for LC  5 precise silicon layers to replace TPC  56 m 2 silicon  R&D needed:  Improve resolution to 5  m  Improve radiation length  Improve rad hardness  Track stamping possible at nanosecond level  2 separation for out-of-time tracks for different drift direction configurations

67. 19th February, VCI 2007 Paula Collins, CERN 67 particle Si s Vacancy + Interstitial Point Defects (V-V, V-O.. ) clusters E K > 25 eV E K > 5 keV Frenkel pair V I charged defects  N eff, V dep e.g. donors in upper and acceptors in lower half of band gap generation  leakage current Levels close to midgap most effective Influence of defects on the material and device properties Trapping (e and h)  CCE shallow defects do not contribute at room temperature due to fast detrapping

68. 19th February, VCI 2007 Paula Collins, CERN 68  Wide band gap (3.3eV)  lower leakage current than silicon  Signal: Diamond 36 e/  m SiC 51e/  m Si80 e/  m  more charge than diamond  Higher displacement threshold than silicon  radiation harder than silicon (?) R&D on diamond detectors: RD42 – Collaboration http://cern.ch/rd42/ CCE at high fluences degrades even more in SiC and GaN than in Si. New Materials: Diamond, SiC, GaN

69. 19th February, VCI 2007 Paula Collins, CERN 69