report pixel2000

Pixel 2000 Genova – june 5-8, 2000http://www.ge.infn.it/Pix2000/slides.html Internal report : 

Pixel 2000 Genova – june 5-8, 2000 http://www.ge.infn.it/Pix2000/slides.html Internal report Pixel meeting June 12, 2000 G. Chiodini – Fermilab Overview Rad-hard Sensors (Marina) Rad-hard electronics Hybridization Pixel Module Mechanics and cooling Test beam results Monolithic pixels and 3D pixels X-ray imaging (…, HPD) Miscellanea

Rad-hard electronics: 

Rad-hard electronics All speakers and experimental results validate the Abder’s conclusion: “Deep SubMicron CMOS process is the right way to go” ALICE2Test chip irradiated with X, g, and p survives up to 30 Mrad: W. Snoeys (ALICE beam test) and F.Meddi (ALICE review talk) Review talks of P.F. Manfredi (FE) and P. Jarron (RH-FE) discussed about DSM: Likely high yield and low cost. Total Irradiated Dose Effect: outstanding performance with enclosed geometry and guard ring for n-channel Mosfets. Single Event Latch-up: good immunity (DMILL is immune to it) Single Event Gate Rupture: no evidence in ALICE2Test chip up to 9×1014 p/cm2. Single Event Upset: is an issue (true for all technologies) solved only by circuit design techniques and became worse going to 0.18 or 0.15 micron. Electrostatic Discharge Sensitive worse going to 0.18 or 0.15 micron.

Hybridizations (1/3): 

Hybridizations (1/3) Talk review given by M. Caccia Delphi experience 106 pixels and 150 module Final yield 36 % (not acceptable for ATLAS) Real solutions are: Indium bump-bonding (industrial standard, room temperature, UBM is not complicate). Solder -above all flux less- (not industrial standard, UBM is complicate). R. Horisberg: Development of indium bumping at PSI (some secret recipes) Mass production (400 modules 2004-2005) UBM made by companies Reflow oven (for indium!) and Flip-chip for ATLAS pixel module Spherical 20 mm diameter bumps after reflow Bumps deposited only on the read out chip (for indium!) Larger strength achieved In (273psi) , In-Ag (800psi) , and In-Sn(1720psi)

Hybridizations (2/3): 

Hybridizations (2/3) Round table discussion on bump-bonding Industrial partners AMS (Rome, indium) IZM (Berlin, MCM-D module, solder, electroplating, reflow, 120minute/wafer all bumps inspection) VTT electronics (Finland, solder, electroplating, reflow, no flux) AIT (Usa) sent out an email (I am trying to have it) Discussed topics 8” wafer for 50 mm pitch (A. Mekkaui’s question) Needed for DSM No one is ready now Module reworkability (M. Caccia’s question) Homogeneous detachment and re-bonding Cleaning the surfaces Not a problem for indium but for solder (thermal shock at high T for the chip) Mechanical stress of the sensor (M. Caccia’s talk: no problem for the indium) Companies don’t like that: a reworkability line parallel to the production line Large dead area probability (P. Delpierre’s question) Opposite to random 10-5 failure rate quoted up to now Impact on final yield

Hybridizations (3/3): 

Hybridizations (3/3) Alenia Marconi System (Rome) Very simple process T<500 C and no reflow for indium Thinner chip bonded (lower T and lower P is enough to succeed) Same evaporation system for every step Wafer protected by photo resist in every step High yield, but problems with dies Wafer up to 6” They are thinking about to go to 8’’ wafers Investment in the deposition chamber to increase the size (several hundreds K$) Other equipments are ready C. Gemme: Study of indium bumping for the ATLAS pixel detector 2pixels/Fechip failure rare Threshold from 2000e to 4000e after bonding (7mm+7mm=8mm)

Pixel module (1/2): 

Pixel module (1/2) P.Netchaeva: results on 0.7% X0 thick pixel modules for the Atlas detector 0.7% X0 Material budget (Two metal layer?) Silicon glue, thermo-camera test of T uniformity One tested module from Boeing (150 mm thinned ROC by GDSI after bumping) Two test module from AMS (156 mm thinned ROC by Okamoto after bumping) P.Skubic: Flex Circuit designs for the Atlas pixel detector Design rules, simulation with Maxwell-Spice link, and comparison with test bench Wire bonding experience Vendor experience a lot of companies, only one produced non working sample Cleo III experience with GE (General Electric Corporate Research and Development NY) Flex hybrid Atlas module (LBL) beam test at CERN in May ’99 (SnPb bumps, good results) C.Grah: Pixel-detector modules using MCM-D technology Good bench test and beam test results presented Personal informal discussion suggest to me that it is not reliable up to now

Pixel module (2/2): 

Pixel module (2/2) I. Gregor: Optical links for the ATLAS SCT and Pixel detector Test on Rad-Hardness for SCT optical link (for Pixel optical link in the near future) SEU can be fixed sending more light

Beam Test: 

Beam Test L.Perera: Diamond pixel detectors W. Snoeys: OMEGA3 (ALICE+LHCb) chip in DSM process irradiated with 9×1014 p/cm2 the threshold is changed but not dramatically M.Aleppo: A measurement of Lorentz angle of rad-hard pixel sensors Model Agreement test beam results and model T. lari: A measurement of spatial resolution of Atlas pixel sensors 6 mm telescope resolution Large multiple scattering Error prediction subtracted from the residual distribution gaussian sigma Pixel module beam test already discussed

Mechanics and cooling: 

Mechanics and cooling M. Olcese: Mechanics and cooling for pixel detectors Fluorocarbon coolants are the best choice for pixel (stable, good thermal properties, relatively low viscosity at low temperature) Glue chip-support is an issue Phone conversation about BTeV design

Miscellanea: 

Miscellanea G. Bolla: Measurements of prototype pixel sensors for CMS Analog data optical driver Readout architecture bypassing bad chip or bad column or bad pixel in the token readout. Controlling the single chip average rate to see if there are runaway in the system The reset must be local SEU about 1Hz S. Seidel: Capacitance of Silicon pixels Test bench for Atlas sensors Cback plane = 10-20 fF about 15% total C Cpspray =128 fF and Cpstop = 80 fF CSeiko < CCiS (Why?) Contribution to total C from first neighbors 11%, from after first neighbors 7%