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

Tk

EATTI

B

g

2exp)( 2

::::

B

g

kEAT Temperature

sensor constant Energy gap =1.2 boltzmann constant

VI

::::

V

I Increase dark current damage constant [A/cm] sensor Volume [cm3] radiation flux [/cm2]

• Silicon breaks by Radiation damage:

dark current increases

• Main part of dark current is leakage current depending on temperature:

Setup

• Silicon strip sensor : 1st prototype detector

(2002 Nov : Test beam at KEK)

Currents

Voltage

Thickness: 400um

Channel: 384x384 (sum : 768 strips)

Front

Back

SensorAmmeter Voltage

Setup• device :

Senso

r

•Model 6487 Picoammeter/Voltage Source(Keithley Instruments) Voltage : as high as 500V Currents : 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 85oC (%RH : 0 to 95%)

Curren

ts

Voltag

e

PC

Front Back

Chamber

Ammeter Voltage

ChamberPCSensor 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 ~ 500VCurrent : max 2mATemperature : -10 ~ 30 oCHumidity : 15% , 30%

Result (temperature dependence)

1.E- 10

1.E- 09

1.E- 08

1.E- 07

1.E- 06

1.E- 05

1.E- 04

1.E- 03

1.E- 02

1 10 100 1000

30℃25℃20℃15℃10℃5℃0℃-5℃-10℃

Bias Voltage [V]

Lea

kage

cur

rent

[A

]

Humidity : 30%

1.0E- 10

1.0E- 09

1.0E- 08

1.0E- 07

1.0E- 06

1.0E- 05

1.0E- 04

1.0E- 03

1.0E- 02

260 270 280 290 300

500V400V320V250V200V160V100V50V25V1V

Result (temperature dependence)L

eaka

ge c

urre

nt [

A]

[k]

Temperature

Bias Voltage

Humidity : 30%

-10 -5 0 5 10 15 20 25 30 [oC]

100Vconstant

Test beam @KEK : 80~90 V

@100V

T[oC]

I[uA]

30 70

25 51

20 32

15 20

10 15

5 10

0 8

-5 9

-10 9

Result (humidity dependence)

Bias Voltage [V]

[A]

1.0E-09

1.0E-08

1.0E-07

1.0E-06

1.0E-05

1.0E-04

1.0E-03

0 50 100 150 200

20℃ 30%20℃ 15%10℃ 30%10℃ 15%L

eaka

ge c

urre

nt

[A]

Summary

• RIKEN facility activity• Study temperature dependence of silicon leakage current• Silicon strip sensor : 1st prototype detector

thickness 400um, 768 strips

• Measurement : Bias Voltage 0~500 [V]temperature -10~30 [oC]

Humidity 15, 30 [%]

• Best operating temperature : 10oC, 15uA@100V