Temperature dependence of sensor leakage current Contents Introduction Measurement Result Summary Junkichi Asai (RIKEN BNL Research Center) (Hiroki kanoh (Tokyo Institute of Technology)) VTX Meeting 6/1/2004

Introduction Temperature sensor constant Energy gap =1.2 boltzmann constant Increase dark current damage constant [A/cm] sensor Volume [cm 3 ] radiation flux [/cm 2 ] Silicon breaks by Radiation damage: dark current increases Main part of dark current is leakage current depending on temperature:

Setup Silicon strip sensor : 1 st prototype detector ( 2002 Nov : Test beam at KEK) Currents Voltage Thickness: 400um Channel: 384x384 (sum : 768 strips) Front Back Sensor Ammeter Voltage

Setup device : Sensor Model 6487 Picoammeter/Voltage Source( Keithley Instruments) Voltage : as high as 500VCurrents : as low as 20fA DAQ controlled by LabVIEW7 ( programming by H. Kanoh ) PC : Windows Connect : PCI-GPIB Temperature and Humidity controlled chamber (ESPEC LHU-113) T: -20 to 85 o C (%RH : 0 to 95%) Currents Voltage PC FrontBack Chamber Ammeter Voltage Chamber PC Sensor Box

Measuring condition Sensor : In the chamber dark room keeping over 1day (for light sensitive) IV measurement : bulk=768 strips (not channel by channel) Bias Voltage : 0 ~ 500V Current : max 2mA Temperature: -10 ~ 30 o C Humidity: 15%, 30%

Result (temperature dependence) Bias Voltage [V] Leakage current [A] Humidity : 30%

Result (temperature dependence) Leakage current [A] [k ] Temperature Bias Voltage Humidity : 30% [ o C] 100V constant Test : 80~90 T[ o C ] I[uA ]

Result (humidity dependence) Bias Voltage [V] [A ] Leakage current [A]

Summary RIKEN facility activity Study temperature dependence of silicon leakage current Silicon strip sensor : 1 st prototype detector thickness 400um, 768 strips Measurement : Bias Voltage 0~500 [V] temperature-10~30 [ o C] Humidity 15, 30 [%] Best operating temperature : 10 o C,