rd50 collaboration overview: development of new radiation ... · 28.05.15 rd50 overview:...

Susanne Kuehn, Albert-Ludwigs-University Freiburg

On behalf of the RD50 Collaboration

RD50 Collaboration Overview: Development of New Radiation Hard Detectors

FRONTIER DETECTORS FOR FRONTIER PHYSICS13th Pisa Meeting on Advanced Detectors

28.05.2015

RD50 Overview: Development of new silicon detectors - Susanne Kuehn 228.05.15

Outline

• Introduction

• Results from Research Fields of the RD50 Collaboration aiming for radiation hard detectors for future collider experiments

– Defect Characterization

– Detector Characterization and Full Detector Systems

– Development of New Structures

• Summary

Only a selection on interesting topics, the full variety of RD50 can be found on: http://rd50.web.cern.ch/rd50/


Structure and Research Fields of RD50

Co-Spokespersons Gianluigi Casse and Michael Moll (Liverpool University) (CERN PH-DT)

Defect / Material Characterization

Ioana Pintilie(NIMP Bucharest)

Detector Characterization

Eckhart Fretwurst(Hamburg University)

Full Detector Systems

Gregor Kramberger (Ljubljana University)

● Characterization of microscopic properties of standard-, defect engineered and new materials pre- and post- irradiation• DLTS, TSC, …• SIMS, SR, …• NIEL (calculations)• WODEAN: Workshop

on Defect Analysis in Silicon Detectors(G.Lindstroem & M.Bruzzi)

• Characterization of test structures (IV, CV, CCE, TCT)

• Development and testing of defect engineered silicon devices

• EPI, MCZ and other materials• NIEL (experimental)• Device modeling• Operational conditions• Common irradiations• Devices Simulations (V. Eremin)• Wafer procurement (M.Moll)

• 3D detectors• Thin detectors• Cost effective solutions• Detectors with internal gain

(avalanche detectors)• Slim edges• Other new structures

• 3D (R.Bates)• LGAD (V. Greco)• Slim Edges (Vitaliy Fadeyev)

• LHC-like tests• Links to HEP• Links electronics R&D• Low rho strips• Sensor readout (Alibava)• Comparison:

- pad-mini-full detectors- different producers

• Radiation Damage in HEP detectors

• Test beams (M. Bomben & G.Casse)

New Structures

Giulio Pellegrini (CNM Barcelona)

Collaboration Board Chair & Deputy: G.Kramberger (Ljubljana) & J.Vaitkus (Vilnius), Conference committee: U.Parzefall (Freiburg)CERN contact: M.Moll (PH-DT), Secretary: V.Wedlake (PH-DT), Budget holder & GLIMOS: M.Glaser (PH-DT)

M.Moll 2014


The RD50 Collaboration

41 European institutes Belarus (Minsk), Belgium (Louvain), Czech Republic (Prague (3x)), Finland (Helsinki, Lappeenranta ), France (Paris, Orsay), Germany (DESY, Dortmund, Erfurt, Freiburg, Hamburg, Karlsruhe, Munich(2x)), Italy (Bari, Florence, Perugia, Pisa, Torino), Lithuania (Vilnius), Netherlands (NIKHEF), Poland (Krakow, Warsaw(2x)), Romania (Bucharest (2x)), Russia (Moscow, St.Petersburg), Slovenia (Ljubljana), Spain (Barcelona(2x), Santander, Valencia), Switzerland (CERN, PSI), Ukraine (Kiev), United Kingdom (Glasgow, Liverpool)

6 North-American institutesCanada (Montreal), USA (BNL, Fermilab, New Mexico, Santa Cruz, Syracuse)1 Middle East institute Israel (Tel Aviv)1 Asian institute India (Delhi)

→ 49 institutes and 280 members

+ 22 observers

→ Workshops

→ Irradiation facilities

More details on: http://rd50.web.cern.ch/rd50/

14t h Workshop in Freiburg, 2009

Collaborators from several experiments at the LHC: ATLAS, CMS and LHCb and also from ILC→ Cross-experiment discussions

24t h Workshop in Bucharest, 2014


Challenge: Radiation Damage in the upgrade of LHC

● Planned upgrade of the LHC to HL-LHC (and beyond) For HL-LHC in ~2024: 3000 fb-1 expected integrated luminosity (x6 nominal lumi.)● Expected particle fluences for the ATLAS Inner tracker:

→ RD50 investigates understanding of radiation damage of sensors and aims for development of devices to cope with these requirements

I. Dawson, P. S. Miyagawa, Sheffield University, Atlas Upgrade radiation background simulations

● Pixel damage due to neutrons and pions, strips mainly due to neutrons● Exposure up to 2*101 6 neq/cm2

Further requirements for detectors:- High occupancy → high granularity- Low material budget → thin detectors


Defect Characterization

● Aim: Identify defects causing change of detector properties, namely trapping, leakage current and Ne f f (Vd e p) → use knowledge for device engineering and input to simulations

Defect parameters: cross section, ionization energy, concentration, type

charged defects, Vd e p, Ne f f

capture e, h → trapping

generation e,h → leakage current

● Tools: Defect Analysis on many identical samples performed with the various tools in RD 50 Collaboration

● C-DLTS (Capacitance Deep Level Transient Spectroscopy)

● I-DLTS (Current Deep Level Transient Spectroscopy)

● TCT (Transient Current Technique)● TSC (Thermally Stimulated Current)● CV/IV (Capacity/Voltage vs. Current) ..

● Tests after irradiation with protons, neutrons, electrons and 60Co-gammas and before and after annealing

● Example: Dependence of leakage current on annealing

● Leakage current decreases after annealing, temperature dependent● DLTS result due to defects E4/E5 and E205a

A. Junkes PoS(Vertex2011)035


Defect Characterization Overview

V2 -/0

VO -/0 P 0/+

H152K 0/-H140K 0/-

H116K 0/-CiOi+/0

BD 0/++

Ip 0/-

E30K 0/+

B 0/-

0 charged at RT

+/- charged at RT

Point defects extended defects

Reverse annealing(neg. Charge, contribution increases with ann., cluster related)

leakage current+ neg. charge(current after γ irradiation)

positive charge (higher introduction after proton irradiation than after neutron irradiation)

positive charge (high concentration in oxygen rich material)

● WODEAN (Workshop on Defect Analysis in Silicon Detectors) since 2005

G. Casse, M.Moll, LHCC report 2012, R. Radu 24th RD50 Workshop, June 2014I.Pintilie et al., Appl. Phys. Lett.92 02410, 2008

Defects act as trapping centers and reduce collected charge

Boron: shallow

dopant (neg. Charge)

Phosphorus shallow

dopant (pos. Charge)

Achievements (some):● Consistent set of defects after different irradiations● Defect introduction rates depend on particle type and energy● H152K and E205a indicated to contribute significantly to trapping

E205a -/0 E4 =/-

E5 -/0


Simulation group in RD50

● Goal: development of approach for simulation of performance of irradiated silicon detectors using custom and professional software

TCAD input

Deep Acceptor (-/0)

Deep Donor (0/+)

● Simulations needed to predict electric fields (double junction), trapping● Using effective mid gap levels in simulation (bulk damage using 2 or 3, surface damage by placing fixed charges Q

f at SiO

2/Si interface)

● Large parameter space needs tuning to experimental TCT results (introduction rates, cross sections of defects)

→ Start to have predictive power→ For bulk: I

leak, V

fd, E-field, TCT and CCE,

partially trapping of irradiated sensor → For surface: C

int, R

int, position

dependence of CCE→ Preliminary parametrization of model to

predict CCE→ Tuning to predict E-field profile and compare

with Edge-TCT results

● Aim to prepare common database with cross sections, concentrations

T. Peltola, PSD 2014N-in-p FZ 320 μm and MCz and FZ 200 μm sensors

CCE from simulation vs. testbeam (by CMS Collab.):

Fixed values of Q

f

predict CCE


Detector characterization and full detector systems: Planar FZ detectors

→ n-in-p performs best (brought forward by RD50): ● No space charge inversion● Favourable combination of weighting and electric field after irradiation: maxima at same electrode● Readout at n-type electrodes: collection of electrons (fast), shorter trapping times, enhance amount of charge

Task: Systematic evaluation of strip and pixel sensors connected to fast electronics before and after irradiation with protons, neutrons, pions and gammas→ Selection of geometry and material

N-in-p baseline for upgrade of ATLAS and CMS silicon strip tracking detectors(in current detectors p-in-n)

S. Wonsak, 25th RD50 Workshop Nov. 2014

G.Casse, VERTEX 2008(p/n-FZ, 300μm, (-30°C, 25ns)I.Mandic et al., NIMA 603 (2009) 263(p-FZ, 300μm, -20°C to -40°C, 25ns)

N-in-p FZ after proton, neutron and gamma irradiation, beta source tests after 80 min annealing at 60°C


New structures: Thin FZ detectors

● 100 μm thick sensors show saturation of collected, thicker devices underdepleted● 200 μm collects more charge than 285 μm at moderate voltages (200-300 V) for fluences above 1*101 5 neq/cm2

● 40% CCE for 200 μm thick device● beam tests show 97-99% hit efficiency (100 μm active edge sensor, 300V, 5*101 5 neq/cm2)

Thin detectors – less material● FZ sensors of different thickness and with 450 μm edge, ATLAS FEI4, 25 MeV protons, beta source

S. Terzo, 24rth RD50 Workshop June 2014

● Collected charge of FZ pixel sensors to doses of up to 14*101 5 neq/cm2

● Sensor modules still functional (though inhomogenous irradiation)

B. Paschen, 25rth RD50 Workshop Nov. 2014


Minimize “dead” area of sensors: several techniques

S. Terzo, 23rd RD50 Workshop Nov. 2013

New Structures: Slim/active edge sensors

SCP slim edges● Exploits scribe and cleave technique on planar and 3D devices, passivated edge

VTT/MPI active edges project● Pixel sensors with slim edges, trenches doped by four-quadrant implantation

FE-I3 FZ silicon, 100 μm thick, 125 μm slim edge, threshold: 1500 e-

Hit efficiency (98.9+-3)% at 300 V after 5*1015 neq/cm2

Also under development at HPK

Laser, XeF2 etch, DRIE etch, saw cut

Native Oxide + Radiation or PECVD (n-type), ALD (p-type)V. Fadeyev et al, NIM A 731 (2013) 260

V. Fadeyev, 23rd RD50 Workshop Nov. 2013

Tweezers, new: Dynatex machine

Similar median charge as for other strips

CIS n-in-p, 285 μm thick, 150 μm slim edge, 800 V bias, 4*1015 neq/cm2

Sr90, Alibava, single cluster plot

Overall efficiency, Ileak

and noise unaffected

by edge-cutting

PTI (V. Eremin) & CERN (G. Ruggiero, NIM A604, 2009, 242-245)


sketch of CNM sensor with filled columns

New Structures: 3D sensors

3D sensors:● Doped columns double-sided vertical to surface● Decoupling of depletion voltage and detector thickness (collected charge) but have low-field region● Allows slim edge● Intensively studied in RD50 Collaboration and others

G. Pellegrini, NIM A 592 ( 2008) 38-43

R. Mori, 23rd RD50 Workshop Nov. 2013

Fluence neq/cm2

S. Parker et al. NIMA 395 (1997) 328A. Zoboli et al., IEEE TNS 55(5) (2008) 2775 G. Giacomini, et al., IEEE TNS 60(3) (2013) 2357

Signal efficiency vs. fluence

→ Well performing and detectors from CNM and FBK installed in ATLAS IBL

Efficiency in test beam of CNM sensors: mean 97.5%

ATLAS Collab. JINST 2012, 7 P11010


New Structures: HVCMOS

● Investigations within RD50 started recently ● HVCMOS devices:

● Depleted active pixel detectors implemented in CMOS process

● Sensor element is deep n-well in low resistivity (~10 Ωcm) p-type substrate

● Depletion with 60 V ~ 10 μm → charge collection via drift of ~1000 electrons, short time

● Pixel and strip detectors possible

● Edge-TCT measurements to understand charge collection properties

HVCMOSv3

Drift

Diffusion

Bumps due to amplifier

Edge-TCT

laser beam

scan in y

fast readout amplifier Collection behaviour confirmed

M. Fernandez, 25th RD50 Workshop, Nov. 2014

HVCMOS from I-Peric connected to FEI4 readout chip


New Structures: HVCMOS after irradiation

Several HVCMOS devices tested after neutron irradiation:

C. Weisser, 25th RD50 Workshop, Nov. 2014

● Edge-TCT signal integrated for t < 3 ns

● Edge-TCT signal integrated for 3 ns < t < 25 ns

Drift component contributes before and after irradiation similarly

Collected charge after irradiation lower due to low E-field in bulk

After highest dose reduced collected charge (by 50%) although depletion width similar to unirradiated but trapping

M. Fernandez, 25th RD50 Workshop, Nov. 2014

V=60 V at RT, laser resolution ~8 μm


Full detector systems: Charge Multiplication

Charge multiplication observed after irradiation to 2-5*101 5 neq/cm2

Characterized with different techniques and in different type of devices

G. Casse, NIM A, 624(2011), 401–404

Strip sensors n-in-p

3D sensors n-in-p

Goals: ● Simulation and prediction of charge multiplication● Long term, S/N behaviour● Exploit charge multiplication by junction and device engineering

Charge Collection (Beta source, Alibava readout)

J. Lange, NIM A 622 (2010) 49, 16th RD50 Workshop, June 2010M. Köhler, NIM A, 659 (2011), 272–281,

16th RD50 Workshop, June 2010

- Dedicated R&D in RD50 to understand and optimize multiplication mechanism- Production of new sensors

Diodes

Origin: Irradiation leads to high negative space charge concentration in detector bulk → increase of the electric field close to n-type strips

→ impact ionization


Charge Multiplication: Long term Behaviour and Enhancement

Production of sensors with trenches:● 5, 10, 50 μm deep, 5 μm wide in center on n+ electrode

G. Casse, NIM A 669 (2013) 9-13, P. Fernández-Martínez, NIM A 658 (2011) 98-102

After 5*1015 neq/cm2 neutrons, n-in-p sensor 300 μm thick→ CCE higher for sensors 5 and 50 μm trenches compared to standard sensors

Long term behaviour of multiplication effect:● HPK strip sensor, mixed irradiated to 2.1*1015 n

eq/cm2

and annealed 4200min@RT

● Charge multiplication observed● After long term biasing and subsequent CCE measurements drop in charge seen (observed by several groups)

● Partial recovery after 1 day without bias or temperature treatment (1h at 60°C)● No full recovery of charge

S. Kuehn, 10th Trento Workshop, 2015

HV off1h 60°C

HV off

mailto:4200min@RT


New Structures: Low Gain Avalanche Diodes – LGAD

Diodes with implemented multiplication layer (deep p+ implant): n++-p+-p-p+ to increase S/N with internal gain and readout with std. front-end

G. Kramberger, 24nd RD50 workshop, June 2014

● N-in p detector with p-doped diffusion (Boron) under cathode → enhanced E-field → multiplication layer● Uniform implantion required to avoid aprupt changes in E-field● Edge termination needed: low doping n-well

● Several samples under test:● Gain of up to ~20 before irradiation● Current and noise independent of gain● TCT measurements match simulation and show

dependence of multiplication on Neff

● Thinner substrates (50 μm) enhance time resolution of devices, new devices under test (N. Cartiglia & H. Sadrozinski, 25th RD50 workshop, Nov. 2014)

M. Baselga, 8th Trento Workshop, 2013

H. Sadrozinski, 25th RD50 workshop, Nov. 2014


New Structures: Low Gain Avalanche Diodes – LGAD irradiated

Multiplication effect degrades after irradiation, gain reduces to ~1.5

neutron irradiation proton irradiation (800 MeV p)G. Kramberger,24th RD50 workshop, June 2014

W8: boron implant 2*1013 cm2

Reason for reduced charge and lower gain:● Removal of boron in p-type layer, no trapping effect → Reduced electric field → removal of initial acceptors (more than in std. diodes)● More degradation after proton irradiation (800 MeV p) ● Noise scales with multiplication● Gain dependeds on temperature (high T, low gain)● Additional bulk damage from radiation

→ New technology development required for p-type multiplication layer: Approach to replace Boron with Gallium (heavier, lower penetration depth but higher diffusion coefficient)

→ Potential for fast timing under investigation


Summary

● RD50 is a CERN R&D collaboration: inter-experiment exchange of knowledge, irradiation campaigns, test beams and common wafer and sensor projects, common tools and test systems● Aiming for radiation hard silicon detectors for future collider experiments

● Many topics covered and organised in different research lines● Defect characterization: Detailed understanding of microscopic defects, consistent list● Simulation working group: Simulation results get predictive power, common database ● Full detector systems:

● Plenty of data on n-in-p-type allowing recommendations for silicon tracking detectors at HL-LHC. Slim/active edges deployable option.

● Thin segmented sensors extend fluence range ● Detector Characterization: Charge multiplication effect systematically investigated to allow

its exploitation → new structures (trenches, LGAD, geometry width/pitch, fast detectors)● New Structures developed, produced and tested:

● Slim/active edges: Production controlled and pixel close to edge highly efficient● 3D-detectors: Highly performing and deployed in ATLAS experiment● HVCMOS: Few samples tested, drift signal changes barely after irradiation, diffusion signal

and trapping reduce charge (50% charge after 2*1016 neq/cm2). ● LGAD-sensors: Uniform gain of up to 20 before irradiation, decrease after irradiation due to

boron (acceptor removal). Good electrical performance. New devices with optimized geometry and Ga in preparation

● Thin, low-R strip sensors, ...

Several talks and posters in this session give more details on new structures


Conclusion

Very active community and many projects ongoing!

More on www.cern.ch/rd50

Thank you to all colleagues for material!

http://www.cern.ch/rd50


Backup


Achievements of RD50 in light of LHC experiments

● Observed radiation damage in LHC experiments agrees with predictions developed by RD50● Leakage current increase in ATLAS, depletion voltage evolution in LHCb

● Recommendations for silicon tracking detectors at HL-LHC

● Inner layers with fluences of about 1*101 6 neq/cm2

→ planar sensors collect decent amount of charge, hit efficiency 97%→ n-in-p (or n-in-n) candidate material (important collection of electrons) → thin detectors overcome problem of requirement of high bias voltage, advantageous with doses > 1*101 5 neq/cm2

→ 3D detectors are alternative option and show good performance with lower bias voltage (used now in IBL of ATLAS experiment)

● Outer layer with fluences of about 2*101 5 neq/cm2

→ planar FZ n-in-p sensors baseline for ATLAS and CMS upgrade strip tracker (FZ has reverse annealing after > 12 weeks at room temperature)→ MCz also option, damage is compensated in mixed fluences, long-term beneficial annealing (50 weeks at room temperature).

● Double column 3D detectors developed within RD50 with CNM and FBK option for pixel detectors


Change of Ileak

● Dependence of leakage current for high doses

● Leakage current scales with fluence α = 4.38*10-17A/cm up to ~1*1015 Neq/cm2 for higher doses non-linear

S. Wonsak, 24th RD50 Workshop June 2014

HPK mini strip detectors


Impact of Defects: Change of Neff

● Dependence on particle type: proton vs. neutron irradiation

Epi-DO-silicon

I.Pintilie et al., NIM A 611 (2009) 52-68

● TSC result: ● Donor E(30K) introduces positive space

charge after proton irradiationViolates NIEL hypothesis!

● Introduces more positive space charge in oxygen rich material

● Effect of reverse annealing after irradiation

A. Junkes PoS(Vertex2011)035, I. Pintilie et al., APL 92,024101 (2008)

● TSC result: ● Acceptors H(116K), H(140K), H(152K)

increase with reverse annealing ● H(116K) might depend on oxygen

concentration→ increase of negative space charge

2*101 4 neq/cm2


Defect Characterization

Defect parameters:

I. Pintilie/ R. Radu, 23rd RD50 Workhshop, Nov. 2013

charged defects, V

d e p, N

e f f

capture e, h → trapping


● MCz performs better than FZ● MCz less affected by annealing, stable annealing behaviour ● Improved performance in mixed fields due to compensation of neutron and charged particle damage in oxygen rich MCz

G. Steinbrück, 23rd RD50 Workshop Nov. 2013

New structures: Mcz vs. FZ

● Sensors 200 μm thick, 1.5*101 5 neq/cm2 protonsMCz with [O] ~ 5*1017 cm-3 (introduced by RD50)

FZ

MCz


Detector Characterization: Investigation of Electric Fields with Edge-TCT

N.P

aci

fico

, 2

0th R

D5

0 W

ork

shop

, 2

01

2

● Goal: Measurement of electric field in unirradiated and irradiated devices, usual TCT (Transient Charge Technique) not working due to trapping after irradiation Edge-TCT, G. Kramberger, IEEE TNS, VOL. 57, NO. 4, AUGUST 2010, 2294

● Example: n-on-p strip detector (pitch 80 μm), irradiated to 1*101 6 neq/cm2, with protons, no annealing

MCZ FZ

I(y,t~0) proport. ve+v

h

Different drift velocity in FZ and MCZ silicon

N.Pacifico, 20th RD50 Workshop, 2012G. Kramberger, 5th Trento Workshop, 2010


Full detector systems: Goals and Tools

• Use fast (40 MHz) analogue or binary readout electronics● Determine parameters like collected charge, noise, signal-to-noise by using beta source set-ups, laser set-ups and test beams● Design and realization of pixel/strip detectors in contact with manufacturers

(CiS, CNM, HIP, HPK, Micron, Sintef)

● RD50 test beam setup (additional to other setups in the Collaboration (EUDET, CMS))● Based on ALIBAVA system with analogue fast readout● Device under test and sensors for track reconstruction run with same readout● Allows easy handling and high resolution measurements

Systematic evaluation of strip and pixel sensors connected to fast electronics before and after irradiation with protons, neutrons, pions

ALIBAVA daughter board with detector


Edge-TCT: Lifetime of charges

Estimate and Understand with TCT measurements the charge life time

T. Pöhlsen, 20th RD50 Workshop, 2012

T. Peltola, 23rd RD50 Workshop Nov. 2013


Trenches

P. Fernández-Martínez, NIM A 658 (2011) 98-102

a standard, b poly trench including poly silicon doped with phosphorus, c p-layer with p-type diffusion, d oxide trench


New Structures: Further 3D sensors

E. Vianello, 6th Trento Workshop, 2011

Further development:

A. Montalbano et al., http://dx.doi.org/10.1016/j.nima.2014.03.066

● Overcomes low-field region in 3D detectors● First sample V

FD ~95 V after

1*1016 neq/cm2

● Uniform electric field● Full charge collected by 241Am source test

Next: position-resolved laser tests

3D-Trench Electrode Detector (BNL&CNM)


New Structures: LGAD

Doping :

Distance

DistanceG. Pellegrini, 24th RD50

Workshop, Nov. 2014


Full detector systems: p-type Detectors

● Collected charge reduces at 600 V to 9.0±0.7 ke (~40%)● After 2.8*101 5 neq/cm2: signal-to-noise ratio 12.3±0.1

Example: FZ n-in-p ministrip sensors (HPK 300 μm thick, 80 μm pitch), tested with beta source, readout with ALIBAVA system (40 MHz) and irradiated with pions, protons and neutrons

S. Kuehn, 21rd RD50 Workshop Nov. 2012

Collected charge after 2*1015 Neq/cm2

and annealing

200V

400V

600V

800V

1000V

1100V

● Different steps of annealing visible● Collected charge stable until 320 min (~120 days at room temperature) – no reverse annealing● Enhancement of charge multiplication after 2560 min for voltages above 800 V

p

n

π

π

π

p

pn

rd50 collaboration overview: development of new radiation ... · 28.05.15 rd50 overview:...

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