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Sensor QA at BNL

2004/09/07

Junkichi Asai (RBRC)

(Kieran Boyle (SBU))

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Contents

1. Previous Evaluation of Stripixel Sensor– Result IV (leakage current –Voltage)

CV (Capacitance-Voltage) (at BNL)

2. Preparation– Semi-automatic probe station– IV measurement with comb type– Effect of grounding other strips on IV measurement

3. Schedule of sensor QA– Development/production

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Setup for IV/CV measurement

picture

Bias Voltage

chuck

Micro Scope

Grounded Needle to guard ring

Measured Needle to sensor pad

wafer

Micro Scope

chuck

Measured Needle

Grounded Needle

Dark Box

There are in the Instrumentation Division.

Because the pad size so small, the probe needle is contacted the pad of the wafer by watching through the microscope.

Vacuum hole

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Result : IV/CV measurements

We found leakage current in the range of 100’s nA and capacitance in the 10s of pF range.

400um strip sensor

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• For these measurements, an adjacent channel was grounded. The leakage current decreases by around 1/3.

Effect of grounding other strip

Bias Voltage

chuck

Micro Scope

Grounded Needle to neighbor pad

Measured Needle to sensor pad

wafer

decrease current

Lea

kage

cur

rent

(uA

)

Grounded Needle to guard ring

10-1

10-1

10-2

100

10-1 100 101 102 103

Bias Voltage (V)

With Grounded Needle to neighbor pad

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Why Semi-Automatic Probe station

• With the present manual probe station, measuring one entire wafer (200 measurements) takes ~ 2 weeks.

• To speed up, We use the Semi-Automatic Probe Station

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Ribbon Cable

GPIB Cable

Setup Semi-Automatic Probe station

Probe station

HV/AmmeterKeithley 6487

Switch systemKeithley 7002

LCR MeterAgilent 4263B

Windows LabView

Windows LabView controlled All device through GPIB cable.

Dark BoxMicroscope

Movable stage

chuck

Probe posit

ioner

for Guard

Ring

Probe card

sensorProbe stag

e

Early Oct., they will be moved to the RIKEN Lab room in physics building at BNL. In the room, the clean tent will be set up. Then we can start measurement.

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Probe Card64 x strip needles

330um

80um

64 u strip needles

150um

80um

By RUCKER & KOLLS, INC.

•One needle is used to measure, the other127 are grounded

•Measurement all 384 pad of strip with overlap step by step

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It was pictured by the Imaging card. We can check without looking through the microscope.

64 u needles of probe card

COMB type sensor

u padsThe needles contacted with the u pads

Maximum zoom

Semi-Automatic Probe station with Imaging card

Check the contacting

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IV/CV measurement schematic

Keithley 6487 HV/Ammeter

Agilent 4263B LCR Meter

GND Ring

IV MeasurementCV Measurement

Keithley 7002,7011,7153 switch system

Chuck

measured

n

n-1

CV Measurement (Between strip-strip) IV Measurement (Between strip-strip)

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Result of IV measurement with Semi-Automatic Probe station

Using COMB design for practice

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Effect of grounding other stripsIV Measurement depending on # grounded

400um cutted comb type sensor

1.E+00

1.E+01

1.E+02

1.E+03

0.1 1 10 100 1000

Voltage [V]

Lea

kag

e C

urr

ent

[nA

] GND:0

GND:1

GND:2

GND:4

GND:6

GND:10

GND:14

Mea

sure

dG

ND nee

dle:

0

GND n

eedl

e: 1

GND n

eedl

e: 2

GND n

eedl

e: 4

GND n

eedl

e: 6

GND n

eedl

e: 1

0

GND n

eedl

e: 1

4

Needles of Probe Card

400um

Electric Field

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Schedule of silicon sensor•Preproduction Sensor Soon SINTEF 17 wafers are supposed to arrive at RIKEN, yesterday (9/6)

(500um, STD design, 2 type : sintering process deference)They will be shipped to BNL and UNM, when clean room ready(?)

End of Sep. 20 sensors from Hamamatsu(4 type : thickness=(500um, 625um) , design=(STD, New))

•Clean Room Early Oct. build at RIKEN Lab room in BNL•QA test Now Programing Semi-Automatic station with LabView

Wiring (probe card, Scanner, HV/Am, LCR…) should decide how to measurement Sep. IV/CV measurement at UNM (with probe positoner)

Continue studying sensor response with probe card at BNL Oct. IV/CV measurement at BNL

All wafers are expected to complete QA in Dec. 2004 or earlier