Test of One ALICE Pixel Test of One ALICE Pixel Assembly in the NA48 Assembly in the NA48

BeamlineBeamlineWednesday, June 16 - Thursday, June 17, 2004

Chip and Sensor CharacteristicsChip and Sensor Characteristics

P. Riedler/CERNALICE

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ALICE Pixel - Test Beam SetupALICE Pixel - Test Beam Setup

One plane installed for NA48:

• 1 ALICE assembly• 1 DAQ adapter card• 30 m DAQ cables• 30 m JTAG control cables• LV and HV power supplies• VME crate with r.o. module (Pilot) and JTAG controller• JTAG multiplexer• MXI interface to PC• ALICE PTS software (LabView)

PC remotely controlled from NA48 control room

ALICE SPD carried out test beams in 2001, 2002, 2003 in proton and heavy ion beams at the SPS using a specially developed DAQ system:

ALICE TB 2002 setup with 3 DAQ planes and 5 assemblies

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Giorgio StefaniniFadmar OsmicDOCT

Petra RiedlerPJAS

Alex Kluge Michel MorelMike BurnsPeter Chochula

ALICE pixel team members helping with the preparations and the test:

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Schematic of a Hybrid Silicon Pixel Detector

Readout Chip

Sensor

Bump Bonds

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13.5 mm

15

.8 m

m

• 0.25µm CMOS process• radiation tolerant design

• clocked at 10MHz• 8192 pixel cells with digital output

• ~100 µW/channel

• ~1000 e- mean threshold (~200 e- RMS•~13 mio. transistors

1200 ALICE Pixel Chips will be used in the SPD (Silicon Pixel Detector)

ALICE Pixel ChipALICE Pixel Chip

50 µm x 425 µm pixel cell

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ALICE chip waferNative thickness 725 µmProduced by IBM

Each chip needs to be tested before the wafer is sent for bump bonding.According to a KGD (Known Good Die) map only those chips that fulfill all test criteria are used for bump bonding.

KGD yield on ALICE chip wafer: ~55% (86 chips per wafer in total)

Wafer material:

“electronics grade” 8 in. silicon wafers

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ALICE SensorALICE Sensor

1 ALICE silicon sensor is connected to 5 ALICE readout chips via 40960 bump bonds

Sensor thickness: 200 µm

Wafer material:

High resistivity FZ 5 in. wafer

Pixel size: 50µm x 425µm

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Pb-Sn Bump Bond

Bump BondsBump Bonds

25µm

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Material Budget

Presentation at BOND’03 workshop, CERN, June 2003

J. Salmi/VTT

Requirements for ALICE:<1 % X0 total per pixel layer

e.g.200 µm thick sensorsChip wafers thinned to 150µm after bumpingMultilayer kapton bus with Al

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QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

P. Mikulik et al, http://www.xray.cz/xray/csca/kol2002/doc/petr_mikulik.htm

Thinned Chip Wafers (10-30 µm)Thinned Chip Wafers (10-30 µm)

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Radiation Effects in Silicon

Surface Damage Bulk Damage

Detectors

Sensitive components are located close to the surface

Full bulk is sensitive to passing charged particles

Electronics

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Estimation of the Radiation Effects for Future NA48

VERY PRELIMINARY!Fluence:

Assuming 5000 spills/day, 50MHz particles/cm2/spill and a spill length of 4.8s:

1.2E12 particles/cm2 per day

Assuming pion beam:eq= …hardness factor (9GeV pions:3.6, flat dist.)eq=4.32E12 (1 MeV neutrons)/cm2 per day

Assuming 100 days of running:eq= 4.32E14 (1 MeV neutrons)/cm2 per run

>> Leakage current, depletion voltage, signal, operating conditions,….

Dose: 4.32E14/(6.24E9/(1.66 MeV g-1 cm2))=114kGy=11.4Mrad

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Single Chip ALICE Assembly tested in NA48

•150µm thick ALICE chip•200µm thick sensor

Mounted on a thin test-PCB

Vfd=15VVop=30V, 50V

8192 pixels

Produced 2003, tested inALICE p-TB 2003

Sensor

Chip

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Preparations:May/June 2004: Installation of one ALICE SPD testbeam plane in the NA48 lab

Beam:Wednesday, June 16:

Installation in the beamline at the position of KABES2Begin of data taking

Thursday, June 17:End of beam at about 14.00, reinstallation of KABES2

~140 MB data taken (SPD TB 2003, HI run, 3 weeks: 3GB)

Timeline of the Test in NA48Timeline of the Test in NA48

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More on the tests:see talk by M. Martini