Sensors for CDF RunIIb silicon upgrade LayerR min (cm)1 MeV eq-n cm * * * * * *10 13 Outer AxialSmall Angle Stereo (1.2  ) L0 Active area (mm 2 )40.5 X X X 78.5 Strip Pitch (  m) Readout Pitch (  m) Number of strips1024> Number of RO strips Production quantity SpecificationsValueMeasured value (OUT0 60) Total Leak. Curr. at 20º at 500V< 50 nA/cm nA/cm 2 Bad Channels< 1 %0% V dep 120  250 V117 V Bias Resistance> 1.5 M  1.5 M  Coupling Capacitance> 10 pF/cm13.7 pF/cm Coupling Cap. breakdown100 V> 100 V Total Interstrip Cap.< 1.2 pF/cm0.71 pF/cn Prototype sensors Sensors are manufactured by Hamamatsu Photonics on 6” wafers 60 Outer-Axial and 53 Outer-SAS prototypes have already been produced and delivered to the Testing Institutions Full characterization has been performed at Tsukuba, Purdue and UNM Depletion Voltage f = 10kHz & AC signal=1V Vdep = 117V Interstrip Capacitance f = 1MHz & AC signal=1V Cint(1000V)=3.2 pF 114/116 sensors do not show micro-discharge up to 1kV. Other electrical and mechanical performances are also excellent. Radiation hardness of sensors Radiation hard design:  Single guard ring  3  m overhanging metal (1  m for inner axial)  High resistivity (   26 k  cm) bulk Testing of performances of irradiated sensors:  Neutron irradiation performed on 5 sensors at UC Davis Irradiation Facility (up 1.4* MeV eq-n cm -2 )  Testing performed at Tsukuba University and Purdue University As a result of irradiation, sensors are subjected to: increase in leakage current (linearly scaled with the dose)  increase in shot noise substrate-type inversion (increase of depletion voltage)  increase in operational bias voltage Good S/N ratio provided by: Single strip leakage current I leak  0.98  A at T  -5C Interstrip capacitance  3pF for V fd =130V Interstrip resistance 1G  at V bias =300V Run IIb, up to 15 fb -1 : high luminosity environment The primary goal of the CDF RunIIb Project is to enable the detector to fully exploit the physics opportunities available during Tevatron operation through To fulfill this goal a replacement for the Silicon Micro-Vertex detector is required. Predicted dose for RunIIb silicon from RunIa and IIa Radiation environment in the CDF tracking volume The new Si sensors for SVXIIb Single sided p + n sensors optimized for High Voltage operation  Minimal R&D necessary  High yield  Easy to handle and test Active sensor cooling in the module design  As cold as –5  C at the innermost radii Requirements on the sensors:  n-type silicon bulk  AC coupled (SiO 2 passivation 1  m thick)  Poly-silicon biased  320  15  m thick wafer  Intermediate readout strip design Motivations for a new Si detector The current silicon detector lifetime is limited by: Double sided silicon sensors  Limited (<200 V) applicable Bias Voltage Cooling capabilities  Sensor temperature > ~5  C FE Chip in Honeywell rad-hard 0.8  m bulk CMOS  Acceptable noise up to 5-6 Mrad DOIM (laser diodes in the optical driver)  Acceptable light output up to 800 krad On overall the SVXII & L00 are supposed to last up to an integrated luminosity of  4 fb -1. New silicon sensors Production Sensor delivery will start mid June The three Procurement Institutions (Tsukuba, Fermilab and Kyungpook) will accept the sensors and perform visual inspection and IV test Fermilab will distribute a sub-sample of sensors to the Testing Institutions (Purdue University & UNM) to perform extensive testing Purdue University will carry on the testing on a subsample of irradiated sensors Conclusions Prototypes performances are satisfactory and fulfill the specifications  Leakage current as small as expected  Excellent AC coupling capacitors with no pin-holes  Interstrip capacitance values as expected  Bias resistor as expected Hamamatsu sensors for RunIIb are rad.hard up to  =1.4* MeV eq-n cm -2  Full Depletion Voltage after Irradiation as Expected Anadi Canepa, Purdue University for the CDF RUN2 Silicon Group 9 th Pisa Meeting, La Biodola, Elba Italy, May 25-31