1 / 31

ADVANCES IN SEMICONDUCTOR DETECTORS FOR PARTICLE TRACKING IN EXTREME RADIATION ENVIRONMENTS. Cinzia Da Via’, Brunel

ADVANCES IN SEMICONDUCTOR DETECTORS FOR PARTICLE TRACKING IN EXTREME RADIATION ENVIRONMENTS. Cinzia Da Via’, Brunel University, UK. OUTLINE 1- INTRODUCTION 2- PRESENT STATUS OF RADIATION HARD SILICON DETECTORS UP TO 10 15 n eq /cm 2 3- STRATEGIES FOR SURVIVAL BEYOND 10 15 n eq /cm 2 :

soo
Download Presentation

ADVANCES IN SEMICONDUCTOR DETECTORS FOR PARTICLE TRACKING IN EXTREME RADIATION ENVIRONMENTS. Cinzia Da Via’, Brunel

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ADVANCES IN SEMICONDUCTOR DETECTORS FOR PARTICLE TRACKING IN EXTREME RADIATION ENVIRONMENTS. Cinzia Da Via’, Brunel University, UK OUTLINE 1- INTRODUCTION 2- PRESENT STATUS OF RADIATION HARD SILICON DETECTORS UP TO 1015 neq/cm2 3- STRATEGIES FOR SURVIVAL BEYOND 1015 neq/cm2: a DEVICE GEOMETRY : short collection distance -3D,thin b TEMPERATURE and FORWARD BIAS OPERATION c DEFECT ENGINEERING :O and O2 4- CONCLUSIONS

  2. 27 Km LARGE HADRON COLLIDER CERN - GENEVA INTRODUCTION new physics expected!! BUT NEED HIGH STATISTICS s 14TeV ~6000 tracks per bunch crossing!!

  3. b PHYSICS REQUIREMENTS p p b Most probable Higgs channel H Was it there already?? PRECISE MEASUREMENTS OF • MOMENTUM RESOLUTION • TRACK RECONSTRUCTION • b-TAGGING EFFICIENCY HIGHER STATISTICS NEEDED FOR Aleph • ACCURACY OF STANDARD MODEL PARAMETERS • ACCURACY OF NEW PHYSICS PARAMETERS • SUPERSYMMETRIC PARTICLES • EXTRA DIMENSIONS • RARE PROCESSES (TOP DECAYS, HIGGS PAIRS ETC) GOOD TRACKER ESSENTIAL! ~10 SMALLER PITCH SILICON DETECTORS CAN DO IT!!!

  4. total n p other charged hadrons RADIATION ENVIRONMENT AT LHC AND SLHC B-LAYER ~4cm 1.6x1016 ATLAS >85% Ch hadrons 210 m2 of microstrips silicon detectors Multiple particle environment: NIEL scaling 1 MeV n equivalent Violation observed for oxygen rich materials ~5x1014 ~5x1015 Data from CERN-TH/2002-078

  5. - - - - - - + + + + + + SILICON DETECTORS "NORMALLY " USED IN PARTICLE PHYSICS • Substrate normally: • n-type • 4 k-cm FZ • Doping of ~1012 cm-3 • [O] ~1015 cm-3 • [C] ~1015 cm-3 • 300mm thick • Orientation <111> 300 mm +V oxide W Incident particle p-type junctions metallised strips n-type substrate

  6. RADIATION INDUCED BULK DAMAGE in Si Primary Knock on Atom Displacement threshold in Si: Frenkel pair E~25eV Clusters E~5keV Vacancy Interstitial Van Lint 1980

  7. Ec Ei V6 VO- Ec - 0.17eV Ev V2(=/-)+Vn Ec-0.22eV V2(-/0)+Vn Ec-0.40eV V2O CIOI(0/+)EV+0.36eV RADIATION INDUCED STABLE DEFECTS IN SILICON From Cern ROSE RD48 Neutron irradiated DEFECT KINETICS ( 300K ): IMPURITIES V,I + DOPANTS • CHARGED DEFECTS ==>NEFF, VBIAS • DEEP TRAPS, RECOMBINATION CENTERS ==>CHARGE LOSS • GENERATION CENTERS==>LEAKAGE CURRENT DLTS spectrum • VO effective e and h trap • V2 and V2O deep acceptors • contribute to Neff

  8. PRESENT RESEARCH FOCUSES AT FLUENCES UP TO 1x1015 n/cm2 STANDARD 300mm n-type SILICON at 1015 n/cm2 10 years of operation at L=1034 cm-2s-1 at R=4 cm EFFECTIVE DRIFT LENGTH Due to charge trapping~150mm e- ~50mm h SPACE CHARGE-ve Neff (1013/cm3) ~ VFD (5000V)~F TYPE INVERSIONdepletion from n-contact (e-field) REVERSE ANNEALINGINCREASE OF -ve Neff temp. dep LEACKAGE CURRENT prop to F (I/V ~5x10-17F) • Signal formation • Charge sharing • Speed • Double junction • Charge diffusion • Noise • Thermal runaway Time [y] • Maintenance

  9. MAIN DETECTOR STRATEGIES PROPOSED FOR LIFE ABOVE 1015 n/cm2 OPTIMIZATION OF: STRATEGIES: • COLLECTION DISTANCE • CCE (trapping) • SPEED • SPACE CHARGE • REVERSE ANNEALLING • CCE (undepletion) • CHARGE SHARING • LEAKAGE CURRENT • DEVICE GEOMETRY • 3D, THIN • DEFECT ENGINEERING • O, P-TYPE SUBSTRATE • MODE OF OPERATION • Temperature, Forward bias MORE TO GAIN BY COMBINING TECHNIQUES!

  10. EFFECTIVE DRIFT LENGTH Leff = tt x Vdrift ( mt ) V Measured values Leff at 1016 proton/cm2 ~ 20 mm electrons ~ 10 mm holes Simulation by S. Watts/Brunel Accepted for publication on NIM Data avalable for neutron andprotons for effective trapping time 220K-300K from Kramberger et al

  11. e- h+ SIGNAL FORMATION AFTER IRRADIATION W. Shockley, Jour. Appl.Phys. 9,635 (1938) S. Ramo, Proc. of I.R.E. 27, 584 (1939) Gatti and coworkers RAMO's THEOREM Signal ~ q(Vxw-V0w) e-th/th + (Vcw-Vxw) e-te/te) Depends on carriers drift length 0.16 A/x collecting Trapping Shaping time x Planar device c 0 • Small contact area • Thin substrate • High e-field HOLES DON' T CONTRIBUTE Waiting potential is steeper if contact small compared with detector thickness moreover minimize charge sharing with neighbours due to charge trapping Simulation by S. Watts Accepted for publication On NIMA

  12. p n p n • SHORT COLLECTION DISTANCE: • 3D DETECTOR S. Parker, C. Kenney 1995 • SHORT COLLECTION PATHS 50 mm (300mm) • LOW DEPLETION VOLTAGES <10V (60V) • RAPID CHARGE COLLECTION 1-2n (25 ns) • EDGELESS CAPABILITY active edges • LARGE AREA COVERAGE active edges • SUBSTRATE THICKNESS INDEPENDENT : • BIG SIGNALS • X-RAY DETECTION EFFICIENCY for low Z materials p+ n+ n+ Same Generated Charge!!! - - + 300 mm + depletion 50 mm p+ C=0.2pF depletion IEEE vol46 N4 Aug. 99

  13. ETCHING TECHNIQUES DEEP REACTIVE ION ETCHING ELECTROCHEMICAL ETCHING LASER ABLATION ELECTRODE FILLED WITH POLYSILICON Fast, high aspect ratio fs pulses is cleaner, any substrate NIMA 487 (2002) 19 ASPECT RATIO = 11:1, 19:1 20:1<

  14. 3D DETECTOR RESULTS before irradiation DETECTOR THICKNESS 121mm 282e noise PREAMP - SHAPING TIME 1 ms 200 mm PITCH mSTRIP TYPE DETECTOR GAUSSIAN RESPONSE SPEED 1.5ns rise AT 130K 3.5ns rise AT 300K 350 e rms , fast electronic designed at CERN- microelectronics group 200mm pitch detector TO BE PUBLISHED

  15. 3D RADIATION RESULTS AT 300K After irradiation NON OXYGENATED 1x1015 p/cm2 (5x1014n/cm2) 100mm pitch detector FULL DEPLETION BIAS = 105 V AFTER 2x1015 n/cm2 SPEED 3.5 ns rise time 40V bias, 300K IEEE Trans on Nucl Sci 48 (2001) 1629 joined work Brunel, Cern, Hawaii To be published

  16. Vbias Vsig Vbias Vbias Vsig Vbias n p 100 m n n p n 200m 100 m 3D CHARGE COLLECTION EFFICINECY After irradiation More on 3D later this morning (P. Roy, 11:30) = 40V =40V CCE =61% USING THE INTEGRATED 22-25 KeV X-RAY PULSES FROM A 109Cd SOURCE COLLECTION FROM p-ELECTRODE 134 m 1 x 1015 p/cm2, 300 K Non-Irradiated, 300 K No Oxygen Diffusion Reverse Annealed Brunel, CERN, Hawaii to be published

  17. MAIN DETECTOR STRATEGIES PROPOSED FOR LIFE ABOVE 1015 n/cm2 OPTIMIZATION OF: STRATEGIES: COLLECTION DISTANCE CCE (trapping) SPEED SPACE CHARGE REVERSE ANNEALLING CCE (undepletion) CHARGE SHARING DEVICE GEOMETRY 3D, THIN DEFECT ENGINEERING O2, P-TYPE SUBSTRATE MODE OF OPERATION Temperature, Forward bias MORE TO GAIN BY COMBINING TECHNIQUES!

  18. - - - - - - - - - - SPACE CHARGE after Irradiation – type inversion At 300K Introduction of radiation induced Deep acceptors Active volume before irradiation p+ n+ W Type inversion d Active volume after irradiation High field AFTER TYPE INVERSION DEPLETION STARTS FROM n+ CONTACT

  19. THE OXYGEN MIRACLE : ROSE/RD48 REDUCED VFD 3 times Reduced Reverse Annealing Saturation (2 times) Nucl. Instr. Meth. A 466 (2001) 308

  20. NEUTRON PROTON PUZZLE COMPETING MECHANISM DUE TO COULOMB INTERACTION MORE POINT DEFECTS WHEN CHARGED PARTICLE IRRADIATION V+O = VO DOES NOT CONTRINUTE TO NEFF V2+0 = V2O CONTRIBUTES TO NEFF

  21. CHARGE COLLECTION EFFICIENCY AFTER IRRADIATION p-type bulk non p - W p+ n+ - d - - - High field Qcoll = q * d/W  Vbias Standard p on n TRAPPING Oxygenated p on n 25ns electronics 3x1014 n/cm2 T=-170C 0 100 200 300 400 500 600 UNDEPLETED REGION 1 – 3 x 1014 n/cm2 OXYGEN ONLY DOES NOT HELP! NIMA 487 (2002) 465-470 Vbias NIM A 412 (1998) 238

  22. ATLAS PIXELS AFTER 1015 n/cm2 Nucl Inst Meth A 456 (2001) 217-232 These data curtesy from L. Rossi, unpublished • n+ on n • oxygenated • 250 mm • Multi guard - p-spray CCE = 97.7% AT 600V 250mm Time=10ns COMBINED STRATEGIES!! 13 mm Spatial resolution

  23. >1015 n/cm2 1-5 x 1014 n/cm2 EFFECT ON CHARGE SHARING Diffusion due to low field region after type inversion Double sided strips 3.1014 n/cm2 p+ LHCb n+ Resolution [mm] Vbias Vbias NIM A 440 (2000) 17 p side n side p+ ATLAS Efficiency Vbias Vbias NIMA 426 (1999) 140 NIM A 450 (2000) 297 SIMULATION S WATTS UNPUBLISHED

  24. SPACE CHARGE Below 200 K NEFF DECREASE WITH T!! • CCE INCREASES! • Low leakage current LAZARUS effect • No reverse annealing • High carriers mobility energy level occupancy ~ e- E/kT NEFF 1x1014 n/cm2 > type inverted : -ve SC TRAPPING Neff [cm-3] Phosphorus doping level +ve SC NIM.. T [K] C Da Via To be published Nucl Inst Meth A 413 (1998) 475 Nucl Inst Meth A 440 (2000) 5

  25. FORWARD BIAS OPERATION AT LOW TEMPERATURE d Reverse bias Forward bias NIM A 440 (2000) 5 0 min x f = 1015 n/cm2 T=130K 5 min CCE % 15 min 30 min "polarization effect" time V bias undepleted Higher CCE Forward bias 90 V td ~ eE/kT Reverse bias, 700 V T=249K (-24C) f = 1015 n/cm2 NIM A 439 (2000) 293.

  26. IF IRRADIATION AT 130K: different kinetics! 1- formation of defects V, I, Vn, In, depending on particles 2- V + and V- observed already at 4.2K after e- irradiation 3- V present in 5 charge states V2+, V+, V0, V-, V2-. 4- the V spectra disappear at : ~70K in n-type low res ~150K in p-type ~200K in high res. material 5-at 200K new spectra appears (V2, VO) => V migrates!! 6- V migration also possible by ionisation = athermal process 7-I mobileat 4.2K in p-type, ~140-175K in n-type After annealing at 200K better by 20% CCE % Irradiated at 300K For comparison (G. Watkins .Mat. Sci. in Sem. Proc. 3 (2000) 227) voltage Systematic study needed! NIM A 476 (2002) 583

  27. OXYGEN INTERSTITIAL Si Si Si Si Oi Oi Oi Si NEW DEFECT ENGINEERED MATERIAL: O-DIMER TO CONTROL CHARGE TRAPPING 1.1 x1011 p/cm2 OXYGEN DIMER HIGH TEMPERATURE 60Co g IRRADIATION AT T > 350 0COXYGEN ATOMS BECOMES MOBILE AND START TO CLUSTER QUASI CHEMICAL REACTIONS: V+Oi => VOi VOi + Oi => VO2i I + VO2i => O2i D= dimerized p=proton irradiated NIM B 186 (2002) 111 DLTS shows VO suppressed Less trapping! Theory predicts VO2 is NEUTRAL!

  28. SUMMARY • WE KNOW HOW TO: • 1- HAVE A SHORT COLLECTION DISTANCE + COLLECTING e- • optimise signal formation • spatial resolution • speed • 2- CONTROL THE SPACE CHARGE • power dissipation (noise) • CCE • spatial resolution • 3- CONTROL CHARGE TRAPPING • CCE • spatial resolution USING : device structure 3D – THIN (small pitch) Defect engineering operational mode Temperature, forward bias Defect engineering p-type operational mode MORE GAIN BY COMBINING TECHNIQUES!!!

  29. CONCLUSIONS • THE COMBINATION OF: • ENGINEERED SILICON (oxygen enriched), p-type substrate • INNOVATIVE SHORT DRIFT LENGTH GEOMETRIES (3D, thin) • OPERATIONAL CONDITION (temperature, forward bias) • COULD PROVIDE THE RADIATION TOLERANCE OF SILICON NEEDED TO • GUARANTEE THE OPERATION OF PARTICLE TRACKERS AT 1016 n/cm2 • ELECTRONICS PLAYING A KEY ROLE!! • Recently formed CERN R&D (RD50) will explore several of the proposed strategies • Interest expressed by LHC elastic scattering, Luminosity monitor collaborations to use existing technologies like 3Dand cryogenic silicon.

  30. ACKNOWLEDGEMENTS Luca Casagrande/ Roma GianLuigi Casse/Liverpool Alex Chilingarov /Lancaster Paula Collins/Cern Leo Rossi /Atlas pixel Mahfuzur Rahman/Glasgow Angela Kok, Anna Karpenko,Gennaro Ruggiero/ Brunel Erik Heijne/Cern Sherwood Parker/Hawaii Steve Watts /Brunel

  31. “The most important thing in science is imagination” A. Einstein

More Related