SSD Development for the ATLAS Upgrade Tracker Meeting Mo., Feb. 26, 2007. 2-6 pm; CERN Rm. 13-3-005 ATL-P-MN-0006 v.1 Development of non-inverting Silicon strip detectors for the ATLAS ID Upgrade 1) DC coupled detectors (Hartmut) 10 2) New results on MCz (Hartmut) 15 3) Irradiation Studies in Japan (Mutsumu) 20 3) Module Plans (Nobu) 20 4) Need for prototype sensors (Phil) 15 5) Manufacturing plans, including financing (Nobu) 20 6) Inactive area due to biasing resistors (Gianluigi) 10 7) Sensor Specs (Nobu) 20 8) Testing program (Hartmut) 10 9) Radiation campaign (Marko) 15 10) Contact to pixels? 1
SSD Development for ATLAS Upgrade Tracker Review by M. Tyndel and C. Goessling ATL-P-MN-0006 v.1 Development of non-inverting Silicon strip detectors for the ATLAS ID Upgrade (draft 30/10/2006 updated after a phone meeting with H. Sadrozinski, P. Allport, G. Casse, N. Unno). The goal of the program is the industrial pre-production of SSD optimized for slhc operation and includes both short and long strips. In addition, the RD activity should take into account the needs of the module development program and plan to have sensors available on the required time-scale. Option to produce prototypes of pixel sensors? HG Moser (MPI) communicated his proposal on thinned sensors The option of DC-coupled sensors should be investigated. The strategy for Czochralski should be elaborated. 2
Coupling DC vs. AC Pro DC: Cost savings Supplier 1: cost difference 10% if poly is used under bond pads, 20% if no ply is used Supplier 2: cost difference 20-30%. Con DC: AC allows very simple biasing of detectors which helps in testing. (In n-on-n pixels, this was accomplished with a bias-dot, which is a punch-through biasing just for testing. This has not been implemented in p-type detectors, and would require a special investigation.) Strip leakage current has to be sinked in the front-end amplifier. This has been discussed by W. Dabrowski and J. Kaplon in Remarks on feasibility of using DC-coupled silicon strip detectors in an Upgraded ATLAS Inner Detector (4 September, 2006). They point out that the sinked leakage current needs to be compensated by the same amount, which leads to an increase in the leakage current noise contribution by a factor 2. Much of the thermal management of the Upgrade SCT is concerned with reducing this noise contribution. Proposed Action: Adopt AC coupled SSD for Upgrade 3
Wafer: MCz vs. FZ MCz Advantages: Better annealing behavior? Especially n-type! 800 700 SFZ ----- MCz Vdepletion (V) 600 500 400 300 200 100 0 M. Bruzzi, STD6, C-V p-type n-type M. Bruzzi, STD6, Carmel Sep. 2006 (100 min @ 80C 500 days @ RT) 0 100 200 300 400 500 600 700 800 900 Time @ 80 deg SFZ 6e14 MCz 6e14 MCz 6e14 SFz 8e14 MCz 8e14 MCz 8e14 SFZ 8e14 4
Wafer: MCz vs. FZ Potential Problem with MCz: Non-uniformity of depletion voltage Due to high-temperature processing? FZ does not have this problem! Irst SMART Diodes N.. Zorzi et al, Trento Meeting Careful temperature treatment required Can dial in desired depletion voltage due to activation of thermal donors Helsinki U.J. Haerkoenen et al, STD6, Carmel Sept 2006 5
Wafer: MCz vs. FZ Non-uniform doping density in MCz: Simple simulation of parallel capacitors with different depletion voltages reproduces the 1/C 2 curves. 2.5E-04 1/C^2 W044-4 10kHz Vdep: 46.0 -> 77.6 V 2.3E-04 1.C^2 [pf -2 ] 2.1E-04 1.9E-04 10kHz sim2 1.7E-04 1.5E-04 40 50 60 70 80 Bias Voltage [V] 6
Wafer: MCz vs. FZ MCz Wafer Non-uniformity shows up in CCE: Irst wafer p-type W044 in C-V and CEE 3.5 3 2.5 Median Q W044 90 110 90 100 90 50 65 90 35 50 45 50 50 80 65 50 10 30 20-20 20 45 40 35 25 med Q [fc] efficiency 2 1.5 1 0.5 0 1.2 1 0.8 0.6 0.4 detector end detector middle detector front 0 50 100 150 Bias Voltage [V] Efficiency at 1fC detector end detector middle 0.2 detector front 0 0 50 100 150 Bias Voltage [V] 7
Wafer: MCz vs. FZ New data: CCE annealing for n-type and p-type MCz similar time structure as C-V M. Petterson et al Irradiated with 26 MeV p to ~2*10 14 cm -2 Binary readout 100ns, 90 Sr beta source 1000min @60 o C = 514 days @RT Bias voltage [V] 180 160 140 120 100 80 60 40 20 0 Bias voltage for 90% efficiency p MCz 253-4 1 10 100 1000 10000 100000 Anneal time @60C [min] Bias voltage [V] 200 180 160 140 120 100 80 60 40 20 0 Bias Voltage for 90% effiency n MCz 187-4 1 10 100 1000 10000 100000 Anneal time @60C [min] 8
Wafer: MCz New data: RD50 6 Micron fabrication ~1-2 kω-cm MCz, expect Depletion Voltage 500-1000V Observe very uniform depletion at about 550V: 1.4E+23 ~1.7 kω-cm 1.2E+23 1E+23 No thermal donor activation 8E+22 No non-uniformity M. Petterson et al 6E+22 4E+22?? 1/C^2 2E+22 0 1/C^2 2552-7 MCz diodes strip of 4 Series1 Series2 Series3 Series4 0 100 200 300 400 500 600 700 Voltage?? 1.4E+23 1.2E+23 1E+23 2552-7 diodes, strip of 5 1/c^2 8E+22 6E+22 4E+22 2E+22 0 Series1 Series2 Series3 Series4 Series6 0 100 200 300 400 500 600 700 Voltage 9
MCz vs. FZ Previous data: Liverpool FZ allows low initial depletion voltage (<100V) >10 kω-cm FZ Good uniformity, Annealing affects under control 100 DETECTOR No 255 FZ 6 Micron M. Petterson et al 10 G. Casse et al VCI 04 1 1 10 100 1000 Proposed Action: Adopt p-type FZ as Baseline continue to investigate high-resistivity p-type MCz 10
Test Program RD50 Strips/ Test diodes Electrical CCE i-v C-V Cint Rint R(Al) Beta source Laser TSC Irradiations n p 11
Irradiation Program: Neutrons Lubljana: (Marko Micuz) Brief summary of neutron availability: - available all year upon short notice (week) - flux > 1012 n_eq/(cm2.s) (full fluence two hours), downgradeable by reactor power - TID ~ 100 krad for 1014 n_eq/cm2 (> krad/s) - sample width ~60 mm, length ~150 mm - bias & cooling - difficult - dosimetry (RADFET, Si diodes, activation foils, exposure time) ~10 % Suitable for irradiations of bare sensors, a bit depending on the design we adopt (width!). For modules need to be careful, activation issues might be serious at the target fluences. The sensors (Si, Al) cool down quite efficiently (days), so mounting on evaluation boards/modules could be done post-irradiation. 12
Irradiation Program: Neutrons Louvain: (Otilia Militaru) UC Santa Cruz had two runs in late 2006 (2*10 14 and 2*10 15 ). Damage coefficients about 2x larger than at 1 MeV. Good dosimetry possible TID ~1%? Cooling possible Future re-charge not cleared yet 13
Irradiation Program: Pions Submitted proposal to PSI in January 2007 with RD50, CMS Contact: Tilman Rohe, PSI Target fluence about 2*10 15 Limited number of small devices ~40?) Irradiation Program: Protons Rd50 Runs in 2007: May, July, September Contact: Michael Moll, Maurice Glasser 14