Status report on the SiLC ongoing activities Frédéric Kapusta, LPNHE-Université Paris 6 & CNRS/IN2P3 On behalf of Aurore Savoy-Navarro SiLC R&D in Europe: Latest since LCWS’04 ALCPG Workshop, Victoria (British Columbia), July 28th to 31st, 2004 Main Topics: Introductory remarks R&D on sensors and test bench results R&D on Mechanics Advances towards transparency Developing techniques to build long ladders Integration issues and simulations studies Concluding remarks ECFA 2004 @ Durham

Introductory remarks: The SiLC international Collaboration (PRC-DESY May 03) Helsinki U. (Fin) Obninsk St. U. (Ru) IEKP Karlsruhe (Ge) Charles U. Prague (CZ) Ac. Sciences.Wien (Au) LPNHE-Paris (F) U. de Genève (CH) Torino U. (I) INFN-Pisa (I) La Sapienza-Rome (I) CNM-Barcelona (Es) Cantabria U. (Es) Valencia IFIC (Es) Europe: BNL Wayne St.U. U. Of Michigan SLAC UCSanta Cruz -SCIPP USA: Korean Institutes Tokyo U. HAMAMATSU Asia: The collaborative effort is developing (regular audio/video confs). Collaboration between several teams on various R&D topics: sensors, electronics, tests, mechanics & simulations. Santander, Valencia and Hamamatsu recently joined SiLC.

R&D sensors Main R&D objectives: Long microstrips (long ladders) Si Drift Keeping an eye on new Si-tech (pixelisation, VFE on detector etc…) Main requests: TRANSPARENCY, PRECISION & BETTER YIELD increased wafers from 6’’ to possibly 12’’ thinner and smaller pitch Expressed interest: Hamamatsu (Now officially part of SiLC) ST Microelectronics/Catania (tbc) CNM-Barcelona as R&D center Others ? New comers are welcome For Si-drift several European teams in STAR, ALICE have good connections with various firms (Canberra …) Lot of expertise from LEP, CDF, and now LHC (ATLAS, CMS and ALICE) Vienna responsible for coordinating the R&D on sensors & contacts with industry (also presently in charge in CMS). Main actions: collaboration with industry based on established connections & test quality procedures for LHC to monitor the R&D & production on sensors.

Sensor Test Quality: set-up in HEPHY-Vienna Semi-automatic sensor probe station for quality Control: system overview Process control scheme: Test structure Test set-up for CMS Silicon tracking; used for tes- ting the sensors mounted on long ladder prototypes for SiLC (similar set-up in Karlsruhe; another one fully automated in Pisa) Self-made chuck and probe card support

R&D on sensors (cont’d) QUALITY TESTS on SENSORS: Ten new GLAST sensors delivered by Hamamatsu for the construction of the second long ladder prototype in Paris were tested at the Test Quality Center (TQC) in HEPHY Vienna (end of June 04): Type S8743, chip size: 8.9500±20 x 8.9500±20 µm, thickness: 410 ± 10 µm strip pitch: 228 µm number of strips: 384 Total C sensor as f (reverse bias), measured between backplane and bias line allows to extract the V depletion of the sensor & to check its thickness Total leakage current as f (reverse bias), measured between backplane and bias line Capacitance = f(V) Total leakage current = f(V) 16 µA 3.5 pF Capacitance (F) Current (A) 0.5 pF o 50 100 150 200 Voltage (V) Voltage (V)

Test Quality on sensors (cont’d) Strip-by-strip tests are performed at a constant bias voltage, and are aimed to identify defective strips ( < 1%). All four tests are performed in the same scan, by contacting DC & AC pads simultaneously and by switching between different measurements. Leakage current of each strip → to identify leaky = noisy strips I_diel measurement identify pinholes. Polysilicon resistor connecting strips to the bias line. The nominal value is required as well as uniformity. Coupling capacitor for each strip is measured to check pinholes and monitor the uniformity of the oxide layer. Tests at TQC in HEPHY-Vienna gives the 10 sensors are OK

1) Detector design and fabrication R&D on sensors cont’d CNM-Barcelona: Centro Nacional de Microelectronica offers interesting expertise's that are of great interest for SiLC, in the following topics: 1) Detector design and fabrication Technologies: P-on-N, N-on-P, N-on-N Pad, strip and pixels detectors High resistivity poly, capacitive coupling, two metal layers, two side processing Limited to 4 inches wafers Radiation hard devices: Oxygenated FZ and magnetic Czochralski silicon (RD50)

2) Device simulation R&D on sensors cont’d ISE-TCAD, TMA, Silvaco Technology simulation Electrical simulation Charge collection charge sharing in 3D

3) Pitch adapter technology R&D on sensors cont’d 3) Pitch adapter technology Aluminum in glass Radiation hard Production for ATLAS forward Semiconductor Tracker Fan-in’s for ATLAS Forward Silicon Tracker Pitch adapters are important in reducing material budget & in providing the best connection with the electronics on detector

4) Packaging Possibilities at CNM Equipment Dek248 Screen printer R&D on sensors cont’d Equipment Dek248 Screen printer ATV reflow oven with vacuum Manual Pick&Place machine Datacon 2200 PPS for fine pitch Techniques SMD Wirebonding Flipchip Standard Temperatures High temperatures: 280ºC Multichip Modules Standard pitch: 400µm. Screen printing Fine pitch: 50µm. Solder electroplating Packaging plays an important role to help reducing material budget (%X0). {Sensor, pitch adapter, packaging, Electronics} = Si-DETECTOR

R& D on sensors: test benches Long ladder read out by VA LabView- based DAQ Signal from LD1060nm Faraday cage 14bits A/D Electronic card: Alims + FPGA Automated test bench in Paris Motorized 3D-table ( ± 10 μ) Most of the SiLC Institutes have well equipped test benches: key tool for detector & electronics R&D Consumer PC: DB, monitoring programs & Bookkeeping From remote: user

Preliminary results on the first long ladder prototype Built by Geneva U/ETH Zurich &LPNHE-Paris Average pedestal per strip using AMS long ladder technique Sensors are 4’’ , 300 µ thick, double-sided, 70 × 40.1 mm2, 110 µ/208µ readout pitch (p: junction side/n: ohmic side). A set of strips are connected in serpentine; thus strips with following length: 28 cm, 56 cm, 112 cm and 224 cm are tested. The long ladder is presently read out with VA64_hdr chip, with 3.7 µs shaping time. The ENC varies from 180 e- at C=0 to 1010 e- for the longest strip (note this is with 3.7µs) 18 Noise in mV 10 Shaping time: 3.7 µs 4 2 50 100 150 200 250 300 350 Capacitance in pF

L=28cm 1.146v L=56cm 0.861v L=112cm L=224cm 0.771v 0.422v In progress now: varying shaping time up to 10 µs to improve results for strip length above 1 m, and focalizing laser beam. Next step: calibration in MIP’s S/N > 10 is achievable even for long strips Signal from LD1060 on strips 28 cm long

R&D on Mechanics CAD design of the architecture of the various elements of the Silicon Envelop, but can be easily translated to the All-Silicon Tracking case Design and construction of the ladder prototype Thermal mechanical studies Alignment techniques are under development at U. of Michigan (FSI) and starting at U. of Cantabria (based on interferometer & LHC expertise) Main R&D aims: Transparency, high precision, simplicity, and easy to build

Ex: CAD design of for- ward tracker structure Ex: detailed CAD (CATIA) of the Si-FCH gives 4 XUV points, from : X, UV, UV, UV, UV, X plans Total width: 127 mm Details of the alveolar structure where false double-sided UV plans are located Similar alveolar CAD design achieved for the SET and idem for the SIT Next step: collaboration with Industry to check feasibility /cost of designed structure and fabrication of a mechanical prototype for further mechanical studies Needed: inputs from full simulation studies (occupancy) on long ladders versus “tiling” with respect to the location of the detector component.

Long ladder construction: 2nd prototype in construction with GLAST sensors Sensors are positioned one by one on assembly frame Gluing of the ladder The long ladder structure is positioned on the 10 sensors with 4 locatings Ready for bonding

Thermal Mechanical Studies 2.5 m long drawer proto Based on tests on a mechanical prototype: Long drawer made of 5 ladders located in its alveolar structure At one end of the drawer: cooling water → cooled air convection by wind turbine + conduction In the alveolar structure Hypotheses of work: External temperature maintained at 35°C. Power dissipation per channel: 400 μW and no power cycling taken into account. The goal is to maintain the temperature on the detector ≤ 30°C, in order to avoid intrinsic noise increase. Prototype results are used to model the CAD thermal software (SAMCEF)

Results obtained in function of time and with water temperature cool down to 6.5°C: encouraging! Conduction + convection by air cooling at 6.5°C at one end of the drawer, maintains the temperature at ~ 31.5°C max even at the other end (2 meter away)

New thermal mechanical studies in Paris Q (conv), F (surface of heat exchange in m2) Calorific power from outside, F(system temperature) Q (convection), F (air flow in Kg/s) From previous studies: 3 parameters must be taken into account to optimize the cooling system: The calorific power Q (convection) The air flow: must be optimised The surface of heat exchange: must be increased

New thermal prototype, built to comply these observations Isolation Thermal hermiticity External T=35o C Higher air flow Instrumented & empty alveolas New alveolar prototype 10x larger exchange surface heat New prototype

New thermal mechanical results Note: water temperature at 19°C ! No need to cool down the water temperature, thus simplified cooling system. Next step: to design and build a mechanical prototype of the C-fiber structure and to design an overall integrated cooling system

Integration studies: on Mechanical side SET Si-FCH In the case of a Large Detector (i.e. with TPC) Silicon-Envelope components are in strategic positions: SIT links μvertex (σ~2-3μm) with TPC (σ~100μm) SET links TPC with calorimeter Similarly in the FW region: FTD and Silicon -FCH. Questions to be answered: In the case of SET & Silicon-FCH especially: One point? What precision? One segment? One track? (requested length of tracking level arm?) How this design compares with SiD in central & FW? SET FTD SIT μvertex

TESLA geometry and Full Simulation of the h0 Z0 → b b m+ m- Integration issues: the full simulation = essential tool BRAHMS(G3) Full Simulation TESLA LC V. Saveliev (Obninsk U.) TESLA geometry and Full Simulation of the h0 Z0 → b b m+ m-

RERECO (G3) Reconstruction: Display TESLA LC Obninsk U. External (SET) & internal (SIT) Silicon tracking layers Event Display of Full Simulation of the h0 Z0 → b b m m and Particle Flow Objects

Mokka(G4) Silicon Tracker Envelope (if TPC central tracker) Obninsk U. Silicon Tracker Envelope for TESLA geometry in Mokka (G4) Monte Carlo

Future plans on simulation studies To pursue the full implementation of the SiLC tracking system within BRAHMS (G3) and GEANT 4 frameworks, in the case of both: The TPC as central tracker Inserting the detailed: SIT + FTD SET Si-FCH (this is well in progress) The All Silicon tracking And have the possibility to study all the related issues, performing comparisons and detailed studies. Collaboration is developing well between European and US teams to perform these studies. Fully G4 simulated H → bb, Z → e+ e- event including SET (detector in white) (Obninsk U.)

Concluding remarks and prospects: Lot of progresses made since this last spring. The collaborative effort is developing well, as a generic R&D, studying BOTH a all-Silicon-tracking system (SiD) and a TPC + Silicon tracking (GLC/TESLA/LD). New comers among which teams also contributing to the LHC Silicon trackers. They bring a unique expertise & available facilities, essential to go ahead in developing the next generation of silicon tracking detectors, that are needed. SiLC = NICE EXAMPLE of LHC x LC POSITIVE SYNERGY Getting slimmer (material budget) will be THE focus. New technologies are/will be helping. GEANT-based simulation inputs are now strongly and even desperately needed to go ahead. SiLC R&D collaboration is really taking speed but a lot of work still ahead of us!!