January 22, Run IIB Silicon workshop Purdue University Bortoletto Daniela, Bolla Gino, Canepa Anadi Hamamatsu testing I-V characteristics up to 1000V Depletion Voltage Coupling Capacitance short at 100V Leaky strip Polysilicon Resistor Sensors received at Purdue: SWA SWA SWA SWA

January 22, Run IIB Silicon workshop Purdue Testing results at sensor characterization I-V characteristics up to 1000V Depletion Voltage Coupling Capacitance & Oxide Leakage Current Polysilicon Resistor Interstrip Capacitance Radiation Hardness Test sensor SWA sensor SWA sensor SWA have been irradiated at U.C.Davies Irradiation Facility on Sept 27th 2002 fluence = MeV eq-n cm -2 fully characterizated

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Sensor 61 I (V=150) =120nA hamamatsu I(150V)=71 nA Sensor 60 I (120V) =62.6nA hamamatsu I(120V)=77.3nA Sensor 69 I (140V) =76.8nA hamamatsu I(140V)=81.3nA Sensor 63 I (V=140)=71nA hamamatsu I(140V)=74.3nA

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Measurement repeated every 30 min sensor biased at V bias =200V except when tested Sensor stabilizes in time

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Neutron irradiation fluence MeV n-eq cm^ -2 Layer 0 Operating temperature T = -5C (TDR 3-16) Leakage current per strip module I strip (V > V d )  95 nA

January 22, Run IIB Siliconworkshop November 25th, 2002 Run IIB Silicon workshop November 25th, 2002 Annealing procedure T=80C sensor 69 Both sensor 60 and sensor 69 I(plateau)  50 m A (T = -25C) sensor 60: 1400 min T=20C sensor 69: 800 minT = 20C & annealing Assuming  =4  A/cm  I(V dep )  7mA Measured value  I(V dep )  5.5mA Estimated Fluence = MeV n-eq Set-up problem

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Sensor at T=-7C except when testing a) Room T -sensor min -sensor min -sensor min b) annealing sensor 69 c) measurements taken one month later than previous slide Leakage current decreases in time NO breakdown observed

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Sensor is biased at V bias =300V No instability is observed

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Sensor 60 Vdep=117 V hamamatsu V dep =140V Sensor 61 Vdep=141 V hamamatsu V dep =160V Sensor 63 Vdep=133 V hamamatsu V dep =160V Sensor 69 Vdep=132 V hamamatsu V dep =150V Hamamatsu values are higher than Purdue measurements

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop ROSE/TN/ Version 1/14.12/2000 V d (20C)=V d (T)*1.0526/[1+A·exp(T/  )] A=  = V d (f)=V d (1kHz)[1-D·log(f/1kHz)] D=0.11+/ After irradiation Sensor 60 T=-25C,f=1kHz V dep =137 V T=20C,f=10kHz V dep =128 V

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop After irradiation & after annealing Sensor 69 to be understood After irradiation Sensor 69 T=20C,f=100kHz: V dep =136 V T=20C,f=10kHz: V dep =119 V

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop After irradiation & after annealing Sensor 69 T=4C,f=1kHz: V dep =197 V T=20C,f=10kHz: V dep =176 V measurement performed after 4 months (2800 min at room T)

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop At f=100Hz Sensor 60 Coupling Capacitance CC= /-0.48pF Sensor 63 Coupling Capacitance CC= /-1.99pF Sensor 69 Coupling Capacitance CC= /-0.97pF Open in the metal ? No evidence after visual inspection

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Sensor 60 Coupling Capacitance CC= /-1.17pF Sensor 69 Coupling Capacitance CC= /-5.34pF

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Sensor 60 Interstrip Capacitance C int = 3.46+/-1.68pF Sensor 63 Interstrip Capacitance C int = 3.17+/-0.01pF Sensor 69 Interstrip Capacitance C int = 3.53+/-0.18pF Trend to be understood ? Cint vs bias voltage as expected

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Sensor 63 Interstrip Capacitance C int = 3.39+/-0.07pF Sensor 69 Interstrip Capacitance C int = 3.43+/-0.08pF No trend is observed high bias voltage

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop C int vs bias voltage in the region at irregular behavior before irradiation Three different set-up 1. Chuck room T 2. Cold chuck T=12C 3. Environmental chamber T=-25C Oxigen-vacancy generation?

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Surface charge decays in time Measurements one month later than results shown in previous slide

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Before Irradiation Sensor 60 R=1.72 +/- 0.2 MOhm Sensor 63 R=1.84 +/- 0.8 Mohm drop due to positive charge trapped inside SiO 2 After Irradiation Sensor 63 R=1.64 +/ MOhm Sensor 63 R=1.7 +/- 0.8 Mohm positive charge decay due to thermal annealing tunnel annealing

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Before Irradiation R=1.86 MOhm After Irradiation R=1.71 Mohm measurements affected by high leakage current

January 22, Run IIB Siliconworkshop Run IIB Silicon workshop Conclusions We have evaluated the performance of Axial Outer Layer: sensors fulfill the specifications: 1.Leakage Current as Small as expected 2.Bad channel Not found 3.Capacitance Values as Expected 4.Bias Resistor as Expected 5.Full Depletion Voltage after Irradiation as Expected sensor appear easy to charge up bias resistance is affected by positive charge trappped inside SiO 2 before irradiation; the effect decreases after irradiation due to positive charge decay (thermal annealing; tunnel annealing) interstrip capacitance is affected by dioxide defects generated during irradiation; these defects decay in time Hamamatsu sensors are radiation hard up to F =1.4* MeV eq-n cm -2