Development of Double-sided Silcon microstrip Detector. D.H. Kah*, H. Park, H.J. Kim (BAERI JikLee (SNU) E. Won (Korea U)

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1 Development of Double-sided Silcon microstrip Detector D.H. Kah*, H. Park, H.J. Kim (BAERI JikLee (SNU) E. Won (Korea U), KNU) 2005 APPI 1

2 1. Motivation 2. Introduction Contents 1. Working principle 2. DSSD (Double-sided Silicon Strip Detector) 3. Electrical Test of DSSD 4. Source Test 5. Radiation Damage Test 6. Summary and Plan 2005 APPI 2

3 Motivation Design Philosophy Intermediate/Front Tracker (LD) Large/Huge View maximize BL 2 - relatively moderate magnetic field - large inner length of ECAL - plays as intermediate trackers - provide de/dx measurement Main/Front Tracker (SD) SiD View compensate for a smaller measurement length with - improved spatial resolution and - higher magnetic field 2005 APPI dhkah@belle.knu.ac.kr 3

4 Motivation Numbers of Silicon Sensor Based on this concept, a total of silicon area is about 56m 2 This means we need about 6000 wafers for the silicon sensor based on 4 inch wafer Wafer size: 10 x 10 cm 2 (4 inch) Number of Wafers:6000(incl.spares) Main/Front Tracker (SD) 2005 APPI dhkah@belle.knu.ac.kr 4

$Diffraction Sensor for$ science Technology Sensor

5 Motivation Applications of Silicon Sensor Medical Imaging Non-destructive Sensor Specialized Sensor Diffraction Sensor for Bio-Structure Space science Technology Sensor 2005 APPI 5

6 Introduction Working Principle (Carrier Generation & Transport) al al [ Carrier(e/h pair) Generation in Semiconductors ] 1.Thermal 2. EM-Radiation (Photon) 3. Charged Particles Reverse Bias [ Carrier Transport ] Carrier (e/h pair) split by E-field :Drift Current 2005 APPI dhkah@belle.knu.ac.kr 6

7 Introduction Working Principle (Why do apply Reverse bias?) [Space charge region for Bias ] Zero Bias : Thermal equilibrium Reverse Bias : depletion region is induce potential barrier lager than zero bias no current Forward Bias : depletion region is reduce flow current To increase the width of the depletion layer to make silicon bulk as sensitive detector volume, [ Glossary ] Space charge region : net charge density due to ionized donors in n-region and ionized acceptors in the p-region Depletion region : another term for space charge region 2005 APPI dhkah@belle.knu.ac.kr 7

8 Introduction Working Principle of DSSD Advantage of Double-sided microstirp Detector Two Dimensional position information Good sensitivity and High speed of response High resolution: Larger signal current than ionization chamber 2005 APPI 8

Introduction DSSD (Double-sided Silicon Strip Detector) Structure DSSD cross-sectional view N + P + High Resistive n-type substrate P + Initial Oxide Passivation oxide The sensor has the double metal

9 Introduction DSSD (Double-sided Silicon Strip Detector) Structure DSSD cross-sectional view N + P + High Resistive n-type substrate P + Initial Oxide Passivation oxide The sensor has the double metal structure for readout signal to reduce the multiple coulomb scattering due to material budget. Double Metal Structure n+ ohmic side 1 st metal 2 nd metal readout line Metal 1 and metal 2 contact (VIA) p+ junction side 2005 APPI dhkah@belle.knu.ac.kr 9

10 Introduction DSSD Parameters L I S T Sensor size Wafer thickness pitch readout trace pitch implant strip # number of readout strip length strip width D C T Y P E p+ side n+ side X (include sawing line) unit µm µm µm µm sensor sensor µm µm The pitches of the sensors are 50 um and 100um for n-side and p-side. But the readout pitches are the same for the n-side and p-side. Sensors have 511 readout channels on each side APPI dhkah@belle.knu.ac.kr 10

11 Introduction Fabrication of DSSD n+ side p+ implant (F1, B1) n+ implant (F2) p+ side via and 2nd metal (B4,B5) 1st metallization (B3) metal contact (B2) metal contact and metal (F3,F4) pad open (F5,B6) F# n+ side B# p+ side n-side : 5 Mask p-side : 6 Mask 2005 APPI dhkah@belle.knu.ac.kr 11

12 Introduction n+ implanted p-stop in atoll DSSD Prototype p+ implanted readout strip readout pad in staggering via in hourglass guard ring contact of the double metal structure has hour-glass form to reduce the capacitance N side P side 2005 APPI dhkah@belle.knu.ac.kr 12

13 Introduction P-Stop Structure Problem : electrical shortening SiO 2 has Positive Charge, so make electron accumulation layer P-Stop Solution : P-Stop structure N-Strip 2005 APPI dhkah@belle.knu.ac.kr 13

Electrical Test of DSSD Method for Sensor Mesurement These drawings and photo

This measurement will provide us information of the bulk characteristics of

+High voltage p-strip p-guard-ring LCZ meter Current meter 380 um High

14 Electrical Test of DSSD Method for Sensor Mesurement These drawings and photo shows the way how we measure electrical properties of our fabricated sensor. This measurement will provide us information of the bulk characteristics of the sensor p+ guard-ring pad N-side Silver paste p+ strip pad n bulk pad +High voltage p-strip p-guard-ring LCZ meter Current meter 380 um High Voltage n-strip p-stop n-guard-ring n-bulk for test GND 2005 APPI dhkah@belle.knu.ac.kr 14

Electrical Test of DSSD Sensor Measurement Devices

is also used as the high voltage power supply source

this probe station LCZ meter is used for capacitance

measurement device and all of results are stored in

15 Electrical Test of DSSD Sensor Measurement Devices Picoammeter for leakage current measurement and it is also used as the high voltage power supply source Probe station sensor can be moved in um scale by this probe station LCZ meter is used for capacitance measurement The Auto Test System controls this measurement device and all of results are stored in computer Scope Wafer Posionor 2005 APPI 15

16 Electrical Test of DSSD Cleaning room All of measurement are done in a cleaning room and fabricated silicon sensor are stored In the desiccator Wedge bonder is used for the connection between sensor and hybrid board 2005 APPI dhkah@belle.knu.ac.kr 16

17 i Electrical Test of DSSD 1. 1st Run Fab Out Sensor Result I-V Test 1E-3 Guardring Current Leakage current(a) 1E-4 1E-5 1E-6 1E-7 1E-8 1E-9 1E-10 A a 1 B b 2 C c 3 D d 4 F E e f 5 6 G g 7 I H h l j R Q P O N M L K J af ag ah ai aj ak al am an k m 14 n 15 o p16 q17 r Ss Tt U 18 u V W v X 19 w x Y Z y AA AB z aa AC 20 ab AD AE ac ad AF AG AH AI AJ AK AL AM AN 21 ae Several failed strips P-strip Leakage ~ P-strip Guard Ring Reverse bias voltage(v) The leakage currents of many silicon strip are about 1nA up to 100 V but leakage current level of silicon bulk (sensor) is about 1mA due to several failed strips which draw high leakage current. This tells us how hard to make all of strips have small leakage current of about 1nA APPI dhkah@belle.knu.ac.kr 17

18 Electrical Test of DSSD 2. Test Run for Optimization of Fabrication To protect sensor, we added nitride in the fabrication process. (a) Oxide Only I-V Test (b) Oxide +Nitride I-V Test 1.E-02 1.E-03 1.E-04 Guardring Current 1.E-02 1.E-03 1.E-04 Leakage Current [A] 1.E-05 1.E-06 1.E-07 1.E-08 Fail Strip Leakage Current [A] 1.E-05 1.E-06 1.E-07 1.E-08 1.E-09 1.E-09 1.E-10 1.E-10 1.E Voltage [V] Oxide Only - Several failed strips - P-strip Leakage : 3 ~ 1.E Voltage [V] Oxide + Nitride - P-strip Fail : Nothing - P-strip Leakage Variation 2005 APPI dhkah@belle.knu.ac.kr 18

19 Electrical Test of DSSD 3. 3rd Run Fab-Out Sensor Result 1.E-03 1.E-04 1.E-05 (a). I-V Test Optimize Fabrication for DSSD Oxidation / Nitride Leakage Current [A] 1.E-06 1.E-07 1.E-08 1.E-09 1.E-10 1.E Reverse Voltage [V] (b). C-V Test LOT3_E_CV_Guard-ring E2T1_CV_G E2T2_CV_G E2T3_CV_G E3T1_CV_G E3T2_CV_G E3T3_CV_G E4T1_CV_G E4T2_CV_G E4T3_CV_G E5T1_CV_G E5T2_CV_G E5T3_CV_G E6T1_CV_G E6T2_CV_G E6T3_CV_G IV test Result P-strip Fail : NOTHING P-strip Leakage : 8 ~ P-Guard-ring Current ~ 100V CV test Result Fully Depletion Voltage : ~100V Operating Voltage : 120V 250 Capcitance(pF) Total leakage current is about 1uA level by adding Nitride process and we are under investigation for current increases around 85V region Reverse Bias(V) 2005 APPI dhkah@belle.knu.ac.kr 19

20 Source Test of DSSD We used Sr-90 beta source for our source test. At this time we did not use any electric hybrid board for this test since we are still developing hybrid board. After we applied bias voltage to sensor, we tried to see sensor response to beta source on the oscilloscope. Schematic of Source Test HV Pre-amp Osilloscope A N P E-field Beta Source High Voltage Pre-amp Osilloscope 2005 APPI dhkah@belle.knu.ac.kr 20

Source Test of DSSD Dark Box No Source Noise

level is worse than Hamamatsu s We are planning

21 Source Test of DSSD Dark Box No Source Noise Test 90 Sr Source?Signal Test Our result shows that peak itself is better than Hamamatsu photo diode but noise level is worse than Hamamatsu s We are planning to do signal-to-noise (S/N) test in this month APPI dhkah@belle.knu.ac.kr 21

22 Radiation Damage Test - introduction 35MeV Proton Beam Test for Radiation Hardness of DSSD 10 12,10 13,10 14,10 15 [number of proton/cm 2 ] DSSD Beam pipe DSSD Sensor holder monitor 2005 APPI dhkah@belle.knu.ac.kr 22

23 Radiation Damage Test - introduction Displacement damage function D(E) / (95 MeV mb) The de values of the proton is the almost same as that of the neutron for this beam energy range For Silicon 100 MeVmb=2.14keVcm 2 /g Particle energy [MeV] 2005 APPI dhkah@belle.knu.ac.kr 23

24 Radiation Damage Test - introduction 1.Log table Target (number of proton/cm 2 ) Sensor Average Current Number of Proton C3T na, 63sec 1.08X G5T na, 125sec 8X C3T na, 250sec 8.88X E3T na,250sec 9.02X E3T na, 42min 8.91X Test Schematic Al Window (2mm) Sensor Monitor colliminator f =1cm 35 Mev DSSD A 1 Beam current A 2 Beam current 2005 APPI dhkah@belle.knu.ac.kr 24

25 Radiation Damage Test : Result of electrical test I-V Test of irradiation DSSD BEAM TEST_C3T3_IV_Pside_10^12 BEAM TEST_G5T2_IV_Pside_10^ Leakage Current (na) Rerverse Bias (V) #of proton/cm 2 C3T3 1st_ nd_ Leakage Current (na) G5T2 1st_ nd_ Rerverse Bias (V) #of proton/cm 2 BEAM TEST_E3T2_IV_Pside_10^14 BEAM TEST_E3T3_IV_Pside_10^ Leakage Current (na) E3T2 1st_ nd_ Rerverse Bias (V) #of proton/cm 2 Leakage Current (na) Rerverse Bias (V) E3T3 1st_ nd_ #of proton/cm 2 Our results show that leakage currents do not have radiation effect up to p/cm 2 But radiation damages are clearly shown above APPI dhkah@belle.knu.ac.kr 25

VA chip will receive analog signal and this will move to ADC for signal readout.

26 Schematics of Readout and DAQ for DSSD DSSD Our sensor is DC-type and RC chip has to be located in the hybrid board. Sensor will be bonded to RC chips by wire bonding. VA chip will receive analog signal and this will move to ADC for signal readout. RC chip HV Wire bonding VA1(-TA) USB2 DAQ FPGA FADC Control Signal H Hybrid Board 2005 APPI dhkah@belle.knu.ac.kr 26

27 Hybrid Board Layout DSSD RC chip VA1(-TA) Hybrid Board P-side biasing line N-side biasing DSSD RC VA biasing line 2005 APPI 27

28 Hybrid Board Design DSSD RC chip VA1(-TA) Hybrid Board As both side of the sensor Biasing RC VA1TA Bias(GND) DSSD Bias(HV) mechanical design for sensor with hybrid board 2005 APPI 28

29 SUMMARY and Plan 1 st Design Sensor - 1 st,2 nd,3 rd Run done we optimize the double-sided silicon sensor and fabricated sensors New Fabrication(2 nd Design) of sensor with feedback from 1st fabricated sensor test measurements just started. one lot takes 3 months Source Test We clearly saw signal peak with the beta source and we will do signal-to-noise test soon. Radiation Damage Test Radiation damage test again with different temperatures and conditions. Extract damage parameters from these measurements Making Hybrid Board Prototype DSSD(DC-type) + RC chip + VA Chip END Thanks (ARIGATO) 2005 APPI dhkah@belle.knu.ac.kr 29

30 EXTRA PAGE 2005 APPI 30

31 Electrical Test of DSSD Sensor Mesurement Method :N side Test (Surface Character) EXTRA PAGE P Stop pad GND N side pad HV P I N HV 2005 APPI dhkah@belle.knu.ac.kr 31

32 Wire bonding EXTRA PAGE Wedge Bonder bias-ring wedge (tip) VA chip adaptor sensor 2005 APPI 32

Review of Silicon Inner Tracker

Review of Silicon Inner Tracker H.J.Kim (KyungPook National U.) Talk Outline Configuration optimization of BIT and FIT Silicon Sensor R&D Electronics R&D Summary and Plan Detail study will be presented