1. Michael Moll CERN, Geneva, Switzerland .
… DT brainstorming
Future RD Focus on radiation hard semiconductor devices … in perspective of DT role
Michael Moll CERN, Geneva, Switzerland .
OUTLINE:
RD50 Collaboration
…brainstorming (personal view)

2. The RD50 Collaboration RD50: 55 institutes and 327 members
46 European institutes Belarus (Minsk), Belgium (Louvain), Czech Republic (Prague (3x)), Finland (Helsinki, Lappeenranta ), France (Paris, Orsay), Germany (Dortmund, Erfurt, Freiburg, Hamburg (2x), Karlsruhe, Munich(2x)), Italy (Bari, Perugia, Pisa, Trento, Torino), Kroatia (Zagreb) Lithuania (Vilnius), Netherlands (NIKHEF), Poland (Krakow, Warsaw(2x)), Romania (Bucharest (2x)), Russia (Moscow, St.Petersburg), Slovenia (Ljubljana), Spain (Barcelona(3x), Santander, Valencia), Switzerland (CERN, PSI), United Kingdom (Birmingham, Glasgow, Lancaster, Liverpool, Oxford, RAL)
7 North-American institutes Canada (Montreal), USA (BNL, Brown Uni, Fermilab, New Mexico, Santa Cruz, Syracuse) 1 Middle East institute Israel (Tel Aviv) 1 Asian institute India (Delhi)
Detailed member list:
G.Casse and M.Moll, RD50 Status Report, May 2017

3. RD50 Organizational Structure
Co-Spokespersons Gianluigi Casse and Michael Moll (Liverpool University, UK (CERN EP-DT)
& FBK-CMM, Trento, Italy)
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)
Cluster and Point defects
Boron related defects
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
Wafer procurement (M.Moll)
Acceptor removal (Kramberger)
3D detectors
Thin detectors
Cost effective solutions
Other new structures
Detectors with internal gain
LGAD: Low Gain Avalanche Det.
Deep depleted Avalanche Det.
Slim Edges
HVCMOS
LGAD (S.Hidalgo)
HVCMOS (E. Vilella)
Slim Edges (V.Fadeyev)
LHC-like tests
Links to HEP(LHC upgrade, FCC)
Links electronics R&D
Low rho strips
Sensor readout (Alibava)
Comparison: - pad-mini-full detectors - different producers
Radiation Damage in HEP detectors
Timing 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 (EP-DT), Secretary: V.Wedlake (EP-DT), Budget holder & GLIMOS: M.Moll & M.Glaser (EP-DT)
G.Casse and M.Moll, RD50 Status Report, May 2017

4. RD50 main achievements & links to LHC Experiments
Some important contributions of RD50 towards the LHC upgrade detectors:
p-type silicon (brought forward by RD50 community) and now used for the ATLAS and CMS Strip Tracker upgrades
n- MCZ and oxygenated Silicon (introduced by RD50 community) might improve performance in mixed fields due to compensation of neutron and proton damage: MCZ is under investigation in ATLAS, CMS and LHCb
Double column 3D detectors developed within RD50 with CNM and FBK. Development was picked up by ATLAS and further developed for ATLAS IBL needs, followed by AFP and TOTEM and now also within CMS/ATLAS upgrades.
RD50 results on highly irradiated planar segmented sensors demonstrated: devices are a feasible option for LHC upgrade
RD50 data and damage models are essential input parameters for operation scenarios of LHC experiments and their upgrades (evolution of leakage current, CCE, power consumption, noise,….) and sensor design (TCAD parameters).
Charge multiplication effect observed for heavily irradiated sensors (diodes, 3D, pixels and strips). Dedicated R&D launched in RD50 to understand underlying multiplication mechanisms, simulate them and optimize the CCE performances. Evaluating possibility to produce fast segmented sensors?
Fast timing sensors: LGAD (Low Gain Avalanche Detectors) were developed within the RD50 community
New characterization techniques and simulation tools for the community: Edge-TCT, Alivaba readout, TPA-TCT, … partly available through spin-off companies. Signal simulation and TCAD tools.
Close links to the LHC Experiments:
Only few RD50 groups are not involved in ATLAS, CMS and LHCb upgrade activities (natural close contact).
Common projects with Experiments: Detector developments; Irradiation campaigns, test beams, wafer procurement and common sensor projects.
Close collaboration with LHC Experiments on radiation damage issues of present detectors.
G.Casse and M.Moll, RD50 Status Report, May 2017

5. Why and how to work in R&D collaborations?
International R&D collaborations
Allow for a good balance between generic and applied R&D
Note that RD performed in the Experiments is usually applied R&D
Allow for common projects involving several (e.g. all LHC) Experiments
Allow CERN Research Board to steer R&D from the highest level
Allow CERN to save resources: RD community providing vast majority of resources
Allow to collaborate on generic RD with Institutions outside the HEP community (e.g. theoretical and experimental solid state physics)
Need close links to Experiments (both in design and operation phase)
Need to participate in applied R&D within the Experiments (most fruitful: collaborators working in the RD Collaboration and in the Experiment)
Need an international committee (i.e. entity accepted by Funding Agencies and Research Community) to be monitored
Example: Fast timing detectors (next 3 slides)
Ongoing example for the benefit of (generic) developments inside a R&D collaboration keeping strong links to (applied) developments in the LHC Experiments
G.Casse and M.Moll, RD50 Status Report, May 2017

6. Sensors with intrinsic gain
Exploit impact ionization (charge multiplication in high field regions) to achieve faster ( improve timing performance) and radiation harderer ( mitigate trapping) sensors.
Main focus: LGAD (Low Gain Avalanche Detectors) gain O(10)
Use of LGAD proposed & developed at CNM within RD50; 3 suppliers (CNM,FBK,HPK) today
Some work on DD-APD’s gain O(500) at 1800V, 1 supplier (RMD USA)
LGAD structure:
Core Region: Uniform electric field, high enough to activate impact ionization
Termination: Confining the high electric field of the core region
Optimization: TCAD simulations and studies on prototype devices
Considerations for optimization:
Gain versus Vbreakdown trade-off, timing performance
Thin detector integration, radiation hardness
Proportional Response (linear mode operation)
Better S/N ratio (small cell volumes and fast shaping times)
[G. Pellegrini et. al., NIM A 765, 2014, 12–16]
G.Casse and M.Moll, RD50 Status Report, May 2017

7. LGAD within RD50 Collaboration
2010: LGAD activities started with CNM project
2012: First 4 inch wafer, 300 µm thick, LGAD
2014: First 200 µm thick LGAD. First Gallium Process
2015: First PiN on 6 inch wafer. First Inverse LGAD
2016: First 50 µm thick LGAD for Timing applications (ATLAS HGTD and CMS CT-PPS. SOI and SOS, 4 inch wafer). Gallium and Carbon Processes
2017: First LGAD on 6 inch wafer
25 Fabrication processes. 200 Wafers processed at CNM
FBK, Trento: 1st batch of LGAD in 2016, 2nd in 2017 (processed, being characterized)
Today: CNM Spain, FBK Italy and HPK Japan produced LGAD’s (3 suppliers) + Micron
LGAD
iLGAD
HGTD/CTPPS
CTPPS
[G. Pellegrini et al., “Low Gain Avalanche Detectors (LGAD)”, Vertex 2016
G.Casse and M.Moll, RD50 Status Report, May 2017

8. LGAD for Timing Applications
6 x 12 mm2
LHC experiments starting to implement/plan on Si based timing detectors with RD50 technology
CTPPS – CMS-TOTEM Precision Proton Spectrometer
Installed in 2016 YETS in two Roman pots two planes of segmented LGAD
Time resolution measured by CTPPS (at high voltage!)
45 mm LGAD on SOI – 1.7 mm2
27ps single device; 16 ps with 3 layers 230 V )
ATLAS AFP - Forward Proton
30 ps up to 3x1014 neq/cm2
57 ps at 1015 neq/cm2 620 V)
ATLAS HGTD - High Granularity Timing Detector
CMS Timing layer
Planning for hermetic timing detector for phase II;
CB approved a full coverage eta 0 – 3 timing layer for MIPs, using crystals in the barrel and LGAD as baseline in the endcap;
Expect:1014 neq/cm2 to 1015neq/cm2; 9m2 silicon sensor surface; (tentative: 40-50mm thick , 1x3mm2 pads, >95% fill factor)
CTPPS: 45mm thick LGAD (SOI)
HGTD LGAD on 50 mm SOI
CMS Timing layer
G.Casse and M.Moll, RD50 Status Report, May 2017

9. Future work on FCC tracking
VERTEX Conference September 2017: Status & Challenges of Tracker Design for FCC-hh, Zbyněk Drásal on behalf of FCC-hh detector working group
Sensor/Frontend Electronics point of view: Showstoppers!!
Need for radhard precise timing detectors 5ps:
 Not existing! …so far 30ps seems feasible.
Need for ultra-radhard detectors
– Present detectors will not work at 6e17 neq/cm2  Not existing! Note: We not even understand the solid state physics in devices irradiated to this level of fluence.
Exploit new technologies, reduce radiation length, reduce complexity (i.e. increase integration) … go monolithic.
….note that RD50 is already working on many of the challenges (next slides)
G.Casse and M.Moll, RD50 Status Report, May 2017

10. RD50 Workplan for 2017/2018 (1/2)
Understand the Physics of radiation damage
Defect and Material Characterization (Convener: Ioana Pintilie, Bucharest)
Consolidate list of defects and their impact on sensor properties (Input to simulation group) including introduction rates & annealing for different type of irradiations and materials
Extend work on p-type silicon including low resistivity material
Understand boron removal in lower resistivity p-type silicon: Performance of MAPS, CMOS sensors, LGAD … adding new macroscopic measurements
Working group on acceptor removal formed!
Characterization of Nitrogen enriched silicon (starting project, wafers ready)
Detector Characterization (Convener: E.Fretwurst, University of Hamburg, Germany)
TCAD sensor simulations
Cross-calibration of different simulation tools (ongoing) and comparison of “TCAD models”
Refine defect parameters used for modeling (from effective to measured defects)
Extend modeling on charge multiplication processes
Surface damage working group
Extend use of signal simulation tools towards fitting of measured data
Extend experimental capacities on e-TCT equipment
Parameterization of electric field (fluence, annealing time, etc.)
Exploit full potential of Two Photon Absorption for sensor characterization; build setup at CERN
Continue parameterization of radiation damage (performance degradation) of LHC like sensors !
Explore fluence range to1017cm-2and beyond (to prepare for future needs in forward physics and FCC)
Provide the tools to characterize and predict damage and optimize devices for performance
G.Casse and M.Moll, RD50 Status Report, May 2017

11. Provide precision timing detectors
RD50 Workplan for 2017/2018 (2/2)
New structures (Convener: Giulio Pellegrini, CNM Barcelona, Spain)
Continue work on thin and 3D sensors (especially in combination with high fluence)
Continue characterization of dedicated avalanche test structures (LGAD, DD-APD)
Understand impact of implant shape and other geometrical parameters on avalanche processes
Study of Gallium based amplification layers and impact of Carbon co-implantation
LGAD, DD-APD: intensify evaluation of timing performance and radiation degradation (Where are the limits? How to overcome radiation damage? How much gain is optimum?)
HVCMOS
Continue characterization of existing devices (close collaboration with ATLAS HVCMOS group)
End of year: submission of first RD50 devices in an engineering run
Full detector systems (Convener: G.Kramberger, Ljubljana University, Slovenia)
Further studies of thin (low mass) segmented silicon devices
Study performance of thin and avalanche sensors in the time domain (Fast sensors!)
Long term annealing of segmented sensors (parameterize temperature scaling)
Continue study on “mixed” irradiations (segmented detectors)
Continue RD50 program on slim edges, edge passivation and active edges
Merging of RD39 into RD50
Cryogenic operation at high fluences?
Links with LHC experiments and their upgrade working groups
Continue collaboration on evaluation of radiation damage in LHC detectors
Continue common projects with LHC experiments on detector developments
Provide precision timing detectors
Go monolithic
Keep close link with the Experiments (both: in planning/preparation and in operation)
G.Casse and M.Moll, RD50 Status Report, May 2017

12. Future RD Comment on RD50/RD51 On the community level CERN EP level DT
Many developments with focus on HL-LHC but already pointing beyond (HE-LHC/FCC)
On the community level
Channel expertise and well functioning network of existing RD (RD50/51/..) into new (LHCC like?) structures to guarantee continuity in RD
Sensors: Merge Electronics and Sensor RD communities together (Monolithic!)
CERN EP level
Keep core expertise and lab infrastructure. Steering RD communities needs credibility which mostly arises out of expertise and significant contribution to the RD program. DT
Excellent service arises out of expertise and knowledge of forefront technologies. Participation in R&D is motivating staff and improving service quality.
Keep and extend our (partly unique) infrastructure to serve both: Service and RD (e.g. semiconductor/gaseous detector characterization/development labs)
G.Casse and M.Moll, RD50 Status Report, May 2017

13. Workpackages with DT involvement?
..again, my interests,need to add cooling/gas/mechanics/integration/DAQ/Controls/….
Monolithic sensors
….follow the CMOS road
Precision timing detectors
Develop detectors with 5ps time resolution
Radiation hardness/Radiation Physics/Radiation damage modelling
Understand/Model/Predict/Mitigate radiation damage on materials and devices
Leave some room for generic RD
Large area silicon detectors (Calorimeters) …
G.Casse and M.Moll, RD50 Status Report, May 2017