RD50 Recent Results Development of radiation hard sensors for SLHC Anna Macchiolo* * Max-Planck-Institut für Physik on behalf of the RD50 Collaboration  The RD50 Collaboration: scope and methods  Defect characterization  Results on irradiated detectors  Planar pixel productions  3D sensor developments OUTLINE

RD50 8 North-American institutes Canada (Montreal), USA (BNL, Fermilab, New Mexico, Purdue, Rochester, Santa Cruz, Syracuse) 1 Middle East institute Israel (Tel Aviv) 247 Members from 47 Institutes Detailed member list: Development of Radiation Hard Semiconductor Devices for High Luminosity Colliders 38 European institutes Belarus (Minsk), Belgium (Louvain), Czech Republic (Prague (3x)), Finland (Helsinki, Lappeenranta), Germany (Dortmund, Erfurt, Freiburg, Hamburg, Karlsruhe, Munich), Italy (Bari, Florence, Padova, Perugia, Pisa, Trento), Lithuania (Vilnius), Netherlands (NIKHEF), 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 (Glasgow, Lancaster, Liverpool) RD50: Nov.2001 collaboration formed ; June 2002 approved by CERN

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Motivation: Signal degradation for LHC Silicon Sensors Strip sensors: max. cumulated fluence for LHC Pixel sensors: max. cumulated fluence for LHC

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Motivation: Signal degradation for LHC Silicon Sensors Strip sensors: max. cumulated fluence for LHC and SLHC Pixel sensors: max. cumulated fluence for LHC and SLHC

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September  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  Influence of processing technology  Material Engineering-New Materials (work concluded)  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  Development of test equipment and measurement recommendations RD50 approaches to develop radiation harder tracking detectors Radiation Damage to Sensors:  Bulk damage due to NIEL  Change of effective doping concentration  Increase of leakage current  Increase of charge carrier trapping  Surface damage due to IEL (accumulation of positive charge in oxide & interface charges)

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Silicon Material under Investigation  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 standard for particle detectors used for LHC Pixel detectors “new” silicon material Material Thickness  m] Symbol  (  cm) [O i ] (cm -3 ) Standard FZ (n- and p-type)50,100, FZ 1–30  10 3 < 5  Diffusion oxygenated FZ (n- and p-type)300DOFZ 1–7  10 3 ~ 1–2  Magnetic Czochralski Si, Okmetic, Finland (n- and p-type) 100, 300MCz ~ 1  10 3 ~ 5  Czochralski Si, Sumitomo, Japan (n-type) 300Cz ~ 1  10 3 ~ 8-9  Epitaxial layers on Cz-substrates, ITME, Poland (n- and p-type) 25, 50, 75, 100,150 EPIn: 50 – 500 p: < 1  Diffusion oxyg. Epitaxial layers on CZ 75 EPI–DO50 – 100 ~ 6  10 17

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Defect Characterization - WODEAN  WODEAN project (initiated in 2006, 10 RD50 institutes, guided by G.Lindstroem, Hamburg)  Aim: Identify defects responsible for Trapping, Leakage Current, Change of N eff  Method: Defect Analysis on identical samples performed with the various tools available inside the RD50 network (DLTS, TSC, TCT, etc.)  ~ 240 samples irradiated with protons and neutrons  Example: identification of defects responsible for long term / reverse annealing  Cluster related defects H(116K), H(140K) and H(152K) (not present after  -irradiation) observed in neutron irradiated n-type Si diodes during 80 o C annealing  Concentrations are increasing with annealing time  contribute to long term/ reverse annealing  Neff can be calculated from measured defect concentrations with TSC including BD and E(30K) defects  Comparison with Neff from CV-measurements shows a very good compatibility

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September I.Pintilie, NSS, 21 October 2008, Dresden Summary – defects with strong impact on the device properties at operating temperature Point defects  E i BD = E c – eV  n BD =2.3  cm 2  E i I = E c – eV  n I =2.3  cm 2  p I =2.3  cm 2 Cluster related centers  E i 116K = E v eV  p 116K =4  cm 2  E i 140K = E v eV  p 140K =2.5  cm 2  E i 152K = E v eV  p 152K =2.3  cm 2  E i 30K = E c - 0.1eV  n 30K =2.3  cm 2 V 2 -/0 VO -/0 P 0/+ H152K 0/- H140K 0/- H116K 0/- C i O i + /0 BD 0/++ Ip 0/-Ip 0/- E30K 0/+ B 0/- 0 charged at RT +/- charged at RT Point defects extended defects Reverse annealing (neg. charge) leakage current + neg. charge (current after  irradiation) positive charge (higher introduction after proton irradiation than after neutron irradiation) positive charge (high concentration in oxygen rich material)

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Silicon materials for Tracking Sensors  Signal comparison for various Silicon sensors Note: Measured partly under different conditions! Lines to guide the eye (no modeling)!  n-in-p microstrip p-type FZ detectors (Micron, 280 or 300  m thick, 80  m pitch)  Detectors read-out with 40MHz (SCT 128A)

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Silicon materials for Tracking Sensors  Signal comparison for various Silicon sensors Note: Measured partly under different conditions! Lines to guide the eye (no modeling)! highest fluence for strip detectors in LHC: The used p-in-n technology is sufficient n-in-p technology should be sufficient for Super-LHC at radii presently (LHC) occupied by strip sensors LHC SLHC

RD50 Charge Multiplication –FZ Strip Sensors CCE increases at SLHC fluences over the expectations CCE>100%  charge multiplication! Most results showing an anomalous high charge collection efficiency have been obtained until now with Micron FZ n-on-p strip detectors Read-out with SCT128A, 25 ns shaping Possible dependence on manufacturer process details investigated with measurements on sensors from a second producer (Hamamatsu Photonics) within the “ATLAS Upgrade Strip Sensor Collaboration” Studies concentrated on fluences relevant to pixels (ATLAS Insertable B-layer and SLHC) Preliminary results show a compatible CCE behaviour [ M. Mikuž, Hiroshima Symposium 2009 ]

RD50 Charge Multiplication –Epi Diodes Epi diodes, 75 and 150  m thick Measured trapping probability found to be proportional to fluence and consistent with values extracted in FZ Multiplication effect more evident for 75  m diodes Smaller penetration depth (670 nm laser)  stronger charge multiplication n-type, 

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Mixed irradiations: 23 GeV protons+neutrons Micron diodes irradiated with protons first and then with 2e14 n cm -2 (control samples p-only, open marker) FZ-p,n: increase of V fd proportional to F eq MCz-n: decrease of V fd, due to different signs of g c,n and g c,p MCz-p at larger fluences the increase of V fd is not proportional to the added fluence –as if material becomes more “n-like” with fluence – same as observed in annealing plots o C g c can be + or - always + [ G. Kramberger, 13th RD50 Workshop,Nov. 2008, ]

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Mixed Irradiations (Neutrons+Protons)  Both FZ and MCz show “predicted” behaviour with mixed irradiation  FZ doses add |N eff | increases  MCz doses compensate |N eff | decreases, proton damage compensate part of the neutron damage 1x10 15 n eq cm -2 [T.Affolder 13 th RD50 Workshop, Nov.2008]  Mixed irradiation performed with:  5x10 14 p (1 MeV equivalent fluence)  5x10 14 n (1 MeV equivalent fluence) More charge collected at 500 V after additional irradiation!

RD50 Planar pixel productions  MPP-HLL thin pixel production (75 and 150  m) on n- and p-type FZ silicon using a wafer bonding technique that allows variable thicknesses down to 50  m  Pre-irradiation characterization of the p-type wafers shows high yield and good breakdown performances  RD50 Planar Pixel project : production of pixels at CiS (CMS and ATLAS geometries) on FZ and MCz silicon with R&D focus on: - direct comparison of n-in-n and n-in-p performances - slim edges (needed for inner pixel layers in ATLAS) - Pixel isolation methods (moderated, uniform p-spray) n-in-n wafer design [M. Beimforde 14 th RD50 Workshop, June 2009] p-type pixels

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September  “3D” electrodes: - narrow columns along detector thickness, - diameter: 10  m, distance:  m  Lateral depletion: - decoupling of detector thickness and charge collection distance - lower depletion voltage needed - fast signal - radiation hard Development of 3D detectors  Fabrication of 3D detectors challenging: modified design under investigation within RD50  Columnar electrodes of both doping types are etched into the detector from both wafer sides  Columns are not etched through the entire detector: no need for wafer bonding technology but column overlap defines the performance. n + columns p + columns p-type substrate metal oxide 3D-DDTC  Two manufacturers: CNM (Barcelona): 14 wafers (p- and n-type) completed Oct FBK (Trento): 3 3D-DDTC batches fabricated with different overlaps

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September D-DTC sensors –Test-beam data [M.Koehler 14 th RD50 Workshop, June.2009] front column back column Overall efficiency: 97.3% Overall efficiency: 98.6% No clustering strips with highest and 2 nd highest signal joined into clusters 2D efficiency at 40 V for Q>2fC  Device from FBK: p-type strip sensor, 50  m column overlap  Test-beam at CERN: 225 GeV/c muons and APV25 analogue readout (40 MHz) Strip structure is clearly visible only when clustering is not applied.

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Test equipment: ALIBAVA  ALIBAVA – A LIverpool BArcelona VAlencia collaboration  System supported by RD50: Will enable more RD50 groups to investigate strip sensors with ‘LHC-like’ electronics [ R.Marco-Hernández, 13 th RD50 Workshop, Nov.2008 ]  Plug and Play System: Software part (PC) and hardware part connected by USB.  Hardware part: a dual board based system connected by flat cable.  Mother board intended: To process the analogue data that comes from the readout chips. To process the trigger input signal in case of radioactive source setup or to generate a trigger signal if a laser setup is used. To control the hardware part. To communicate with a PC via USB.  Daughter board It contains two Beetle readout chips It has fan-ins and detector support to interface the sensors.  Software part:  It controls the whole system (configuration, calibration and acquisition).  It generates an output file for further data processing.

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September RD50 achievements & links to LHC Experiments Some important contributions of RD50 towards the SLHC detectors:  p-type silicon (brought forward by RD50 community) is now considered to be the base line option for the ATLAS Strip Tracker upgrade  n- MCZ (introduced by RD50 community) has improved performance in mixed fields due to compensation of neutron and proton damage: MCZ is under investigation in ATLAS, CMS and LHCb  RD50 results on very highly irradiated silicon strip sensors have shown that planar pixel sensors are a promising option also for the upgrade of the Experiments.  Charge multiplication effect observed for heavily irradiated sensors (diodes and strips). A dedicated R&D effort will be launched in RD50 to understand the underlying multiplication mechanism and optimize the CCE performances.

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September Spares

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September FZ, DOFZ, Cz and MCz Silicon 24 GeV/c proton irradiation (n-type silicon)  Strong differences in V dep  Standard FZ silicon  Oxygenated FZ (DOFZ)  CZ silicon and MCZ silicon  Strong differences in internal electric field shape (type inversion, double junction,…)  Different impact on pad and strip detector operation!  e.g.: a lower V dep or |N eff | does not necessarily correspond to a higher CCE for strip detectors (see later)!  Common to all materials (after hadron irradiation):  reverse current increase  increase of trapping (electrons and holes) within ~ 20%

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September n-in-p microstrip detectors  n-in-p microstrip p-type FZ detectors (Micron, 280 or 300  m thick, 80  m pitch, 18  m implant )  Detectors read-out with 40MHz (SCT 128A)  CCE: ~7300e (~30%) after ~ 1  cm V  n-in-p sensors are strongly considered for ATLAS upgrade (previously p-in-n used) Signal(10 3 electrons) [G.Casse, RD50 Workshop, June 2008] Fluence(10 14 n eq /cm 2 )  no reverse annealing in CCE measurements for neutron and proton irradiated detectors

RD50 Charge Multiplication –FZ strip sensors  CCE increases at SLHC fluences over the expectations at high fluences  CCE>100%  charge multiplication!  Micron n-on-p FZ strip detectors  Read-out with SCT128A, 25 ns shaping  Multiplication effect more relevant for thin (140  m) FZ structures at higher fluences: after heavy irradiation it is possible to recover the full ionized charge  For pixel layers this has the potential benefit of reducing the radiation length of the detector and yield a safer S/N [I. Mandic et al., NIM A603 (2009) 263 ] [G. Casse, 14th RD50 Workshop, June 2009] 300  m

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September CNM Barcelona ( 2 wafers fabricated in Nov. 2007)  Double side processing with holes not all the way through  n-type bulk  bump bond 1 wafer to Medipix2 chips  Further production (n and p-type) Processing of Double-Column 3D detectors 10  m p+p+ n-n- TEOS Poly Junction 2. FBK (IRST-Trento)  very similar design to CNM  2 batches produced (n-type and p-type )  First tests on irradiated devices performed ( CNM devices, strip sensors, 90 Sr, Beetle chip, 5x10 15 n eq /cm 2 with reactor neutrons) : electrons

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September test beam with 3D sensors  Two microstrip 3D DDTC detectors tested in testbeam (CMS/RD50) One produced by CNM (Barcelona), studied by Glasgow One produced by FBK-IRST (Trento), studied by Freiburg [M.Koehler 13 th RD50 Workshop, Nov.2008]

RD50 A. Macchiolo – Max-Planck-Institut für Physik VERTEX 2009 Workshop- Putten (NL) 14 th September D-DTC sensors –Test-beam data