QA Workshop at CERN 3-4 November 2011 2011.11.3 Hamamatsu silicon detectors for high energy physics experiments Kazuhisa Yamamura*, Shintaro Kamada

QA Workshop at CERN 3-4 November 2011

2011.11.3

Hamamatsu silicon detectors for high energy physics experiments

Kazuhisa Yamamura* , 　 Shintaro Kamada


Outline

1. Development and production history of Hamamatsu SSD ( Silicon Strip Detector )

2. Production flow of SSD

3. Failure analysis

4. New dicing technology

5. Design examination of SSD for HL-LHC


Hamamatsu　Si　detectors　for　HEP

Direct detector

Silicon Strip Detector(SSD)

Silicon Pixel Detector

Photo detector

Silicon Photo Diode(PD)

Silicon Avalance Diode(APD)

Multi Pixel Photon Counter(MPPC)


Development　and　production　history　of　SSDｓ at　Hamamatsu

1980 1990 2000 2010

1984～ 1987～

SSSD　production　on　4inch

MarkⅡ ,　 DELPHI　 ,　 ZEUS　,　　ATLAS　,　　etc

1998～

SSD　production　on　6inch

GLAST　,　CMS　,　　etc

1995　～

N　in　N　　on　4inch

ATLAS　prot　,　LHCb　prot

1992～

DSSD　production　on　4inch

DELPHI　,　CLEOⅡ ,　Belle　,　CDF　,　etc

SSSD　 R&D

1989～

on　3inch

DSSD　 R&D DSSD　on　6inch

2009～

prot　,　S-Belle

2inch　⇒ 　3inch


Review　of　　main　SSDs　made　by　Hamamatsu　for　HEP　projectsPROJECT DETECTOR TYPE size QTY. period

MARKⅡ DC-SSSD 3type 3chip/4inch 44 1987

AC-DSSD 3type 1chip/4inch

Pside: punch-through , Nside: poly-Si & DML 2chip/4inch

AC-DSSD 2type

both-side: poly-Si , Nside: DML

DELPHI up grade AC-SSSD , FOXFET 2chip/4inch 330 1994

NOMAD AC-SSSD , FOXFET 2chip/4inch 650 1996～1997

CLEOⅢ DC-DSSD , Pside: DML 2chip/4inch 550 1997～1999

AC-DSSD 3type 1chip/4inch

both-side: poly-Si , Nside: DML 2chip/4inch

AC-DSSD

both-side: poly-Si , Pside: stereo

AC-DSSD

Pside: punch-through , Nside: poly-Si & DML

AC-DSSD

both-side: poly-Si , Nside: DML

ZEUS AC-SSSD 3type , poly-Si 1chip/4inch 950 1999

AGILE AC-SSSD , poly-Si 1chip/6inch 500 2000

PAMELA DC-SSSD 1chip/6inch 300 2000

BELLE up grade AC-DSSD , both-side: poly-Si 2chip/4inch 250 2000～2002

ATLAS AC-SSSD 6type , poly-Si 1chip/4inch 16000 2001～2003

GLAST AC-SSSD , poly-Si 1chip/6inch 11500 2001～2003

CMS AC-SSSD 14type , poly-Si 1chip/6inch 24000 2003～2006

180 1998

CDF-ISL

PAMELA

KEK-B(BELLE) 2chip/4inch

2chip/4inch 60 1997

360

1chip/4inch 550 1998～1999

CLEOⅡ

1997～1999

122 1993～1994

2chip/4inch 130 1993～1994DELPHI

CDF-SVXⅡ


Production　flow　of　SSDs

1) Design of Photo masks

2) Wafer process

3) Wafer inspection

4) Dicing

5) Chip proving

6) Visual inspection

7) Packing

8) Test of long time stability


Design　of　Photo　masks

CAD soft on PC is mainly used for Si detectors.

Each coordinates of figures can be inputted by macro program

made by EXCEL etc.

Photo-mask design of complicated shape like

any angle or rounded strips pattern are acceptable.


Wafer　process

About 10,000 of 6 inch wafers are processed per month.

We have kinds of process ( PDs , Bipolar photo IC , CCDs, C-MOS ).

For SSDs

2,000 wafers per month were processed for LHC mass production.

Available type : SSSD or DSSD, AC or DC-coupling ,

Single or Double-metal

Available thickness : 150 to 650um for SSSD , 320um for DSSD

• Oxidation• Photolithography• Ion Implantation• Poly-Si process• Metal Evaporation• Passivation


CMS-std Cut-off ( on all CMS wafers) contains

Std-Baby detector , Test structures designed by CMS ,

Mos diode , CMS-Monitor diode ( CMS-MD ) , etc.

ALL cut-offs are kept in envelop and delivered with main detector　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

HPK test structure

contains

test structures of poly-Si resistance ,

implant resistance , coupling capacitance , etc.

W6A main detector

W6A-baby detector ( the same design of W6A main detector )

HPK-Monitor diode ( HPK-MD )

CMS-W6A　chip　&　Cut-offs　from　6inch　wafer


Wafer　proving

1) Lot check using TEG

by manual or auto prober

・ implant resistance

・ poly-Si resistance

・ Flat-band voltage

・ capacitance of Cc

・ IV & CV of Monitor PD

2) IV curve of main chips

Chose good wafers

3) Put chip serial number Binary notation at

Scratch PADs on chip

< Auto prober system >


Vfd　and　Leakage　current　for　CMS-thick　type　SSSDs VR

minmaxavespec

CMS- thick　Vfd

0 0 1 4

193

698

998

1676

1932

1407

383

18 0 00

500

1000

1500

2000

2500

60

～

80

～ 100

～

120

～

140

～

160

～

180

～

200

～

220

～

240

～

260

～

280

～

300

～ 300

～

Vfd　[V]

Number　of　Detectors

total　7310min　90Vmax　280Vave　203Vσ 　29V

CMS- thick　ID VR=600V)（

0 0 0 0 7

305

1298

1895

1578

1002

495

270

151766741262315 6

55

0

500

1000

1500

2000

50

～ 150

～

250

～

350

～

450

～

550

～

650

～

750

～

850

～

950

～

1000

～

ID　[nA]


total　7310min　238nAmax　2367nAave　430nAσ 　134nA

Vfd distribution is due to

the resistance variation of wafer

Relatively small leakage current

though big and 500um thickness


Bad　channel　rate　for　CMS-SSDs

CMS- 768ch　type　Bad　ch.

6360

23680 28 8 4 3 2

0

1000

2000

3000

4000

5000

6000

7000

0 1 2 3 4 5 6 7

Number　of　bad　channel


total　6721min　0max　7ave　0.084　　　　　0.011%

CMS- 512ch　type　Bad　ch.

189 40 24 3 4

6471

0

1000

2000

3000

4000

5000

6000

7000

0 1 2 3 4 5

Number　of　bad　channel


total　6731min　0max　5ave　0.055　　　　　　0.010%

Breakdown　of　937　Bad　channels　of　all13452　detectors

42.2%

19.0%

6.7%

0.0%

4.2%

28.0%

0% 10% 20% 30% 40% 50%

Cc　short

ACALshort

ACAL　open

Poly- Siopen

badisolation

Implantopen

DC

AC

More than 95% of detector have no bad channels.

The average of bad channel rate is around 0.01%.

Short of Cc, Open of strip implant, short of AC AL are main factors of bad channel.


Leakage　current　and　bad　channel　rate　for　Belle-L5-DSSDs

Vfd distribution is due to

the resistance variation of wafer

Relatively small leakage current

though DSSD

Id(nA　Vr=100V)

0

5

53

38

27

23

96

24 3 2

0 0 1 0 0 0 0 00

10

20

30

40

50

60

-100

-300

-500

-700

-900

-1100

-1300

-1500

-1700

-1900

total　173min　150max　1481ave　434σ 　218

number　of　bad　ch

0

6

12

17

26

18

10

15

989

11

2 2

4

1

3 32 2

1212 2

32

0 0 0 00

5

10

15

20

25

30

0 2 4 6 810

1214

1618

202224

2628

30

total　173min　1max　26ave　8.06　　　　　0.52%

The average of bad channel rate is 0.52% and larger than SSSD


Long　time　stability　of　ATLAS　proto-type　SSSD

・ Long time stability of dark current under operating at 600V.

・ For 13 days biasing, no abnormalities have been identified.

< 4 probers for checking long time stability>


Failure　Analysis

・ A picture of delivered sensor, whose voltage tolerancecame to be bad during the evaluation at the customer. ・ Hot electron emission was observed at the edge of guard ring. （ reported by customer ）

・ We will check whether there are some weak points at the structure of guard ring.

Hamamatsu PHEMOS200


New　Dicing　TechnologyWe also have Stealth dicer in addition to the traditional blade dicer.

Cut as narrow as 1μm width without chipping.

Baby detectors, Test structures, Mos diodes , Monitor diodes can be cut by stealth dicer in one set and one program.

［ from Hamamatsu homepage］


Comparison　between　cut　edge　and　leakage　current

IV　curve　after　dicing

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

0.01 0.1 1 10 100VR(V)

ID(A

)

28-128-229-129-230-130-230-333-133-2

Leakage current of stealth diced sample

are smaller than that of blade diced one.

Blade 30um

Stealth 30um

Stealth 50um


Requirement of Silicon detector for HL-LHC 　■ 　 HL-LHC radiation environment SSDs (R=30cm)> 1E15 【 1MeVn-eq/cm2 】 PIXELs (R=10cm) > 4E15 【 1MeVn-eq/cm2 】

■ Radiation damages ・ Increase in leakage current ・ Change of the full depletion voltage(Vdep) N type Si : decrease Vdep invert ⇒to P type ⇒increase Vdep P type Si : increase Vdep

・ Decrease in charge collection efficiency■ Higher bias tolerance to use in HL-LHC condition for long time.

■ Small dead space

We are now doing experiment for edge design of slim edge and GR on 320um thickness P type Si material ( initial Vfd is around 200V)


N+ N+ P+

GR

Field width

Distance to edgeP-sub

Sample No Field width Distance to edge

Q 160 280

R 200 320

S 240 360

T 240 400

U 240 450

V 240 600

W 240 750

X 240 1011

■ 　 Sample No. Q to S N+GR width & P+ width are the same Distance to edge are changed ■ Sample No. T to X Field width are the same Distance to edge are changed

Experiment for Slim Edge design


Experiment for Slim Edge design

Onset Voltage vs Edge Distance (70MeV Proton irradiation)

0

200

400

600

800

1000

1200

1400

1600

1800

0 200 400 600 800 1000Edge distance (um)

Ons

et V

olta

ge(V

)

1.0E+141.0E+155.0E+15

Slim Edge I-V (non irradiation)

1.E- 11

1.E- 10

1.E- 09

1.E- 08

1.E- 07

1.E- 06

0 200 400 600 800 1000Vr (V)

I (A)

Q280R320S360T400U450V600W750X1011

［ data from Mitsui et al 2011］

（※ annealed for 80min@60℃）

・ Before irradiation, the sensor of edge distance lager than 450um hold over 1000V tolerance.

・ After irradiation, the voltage tolerance tends to rise.

・ So, if the sensor meets high voltage tolerance before irradiation, It also meets high voltage tolerance after irradiation.


1GR-Narrow

3GR-Wide2GR-Wide2GR-Middle

1GR-Wide1GR-Middle

Experiment for Guard Ring design

■ Distance to edge are the same, field width are the same

■ Number of GR and total width of GR are changed. 1GR ( Narrow , Middle , Wide ) 2GR ( Middle , Wide ) 3GR ( Wide )


Experiment for Guard Ring （ GR ） design

Various GuardRing Onset Volatge(70MeV Proton irraditaion)

800900

100011001200130014001500160017001800

1.0E+13 1.0E+14 1.0E+15 1.0E+16Fluence [neq/ cm2]

Ons

et V

olta

ge [V]

1GR- N 1GR- M1GR- W 2GR- M2GR- W 3GR- W

Various GuardRing I-V(non irradiation)

1.E-11

1.E-10

1.E-09

1.E-08

1.E-07

1.E-06

0 500 1000 1500 2000Vr (V)

I (A)

1GR- N 1GR- M

1GR- W 2GR- M

2GR- W 3GR- W

1GR 2GR

3GR

（※ annealed for 80min@60℃）

・ Before irradiation, multi GR （ 2GR,3GR ） holds higher voltage tolerance than single GR.

・ Width of single GR doesn't influence I-V characteristic.

・ After irradiation, the difference between single GR and multi GR tends to disappear.

・ As mentioned before, GR problem (degradation of voltage tolerance) is reported. So, we must consider from viewpoint of both slim edge design and reliability.

［ data from Mitsui et al 2011］


Summary

1. The history of Hamamatsu SSD is more than 25 years, and have been used for many HEP experiment.

2. We have enough capability to design, process, inspection and check reliability for Si detector for HEP.

3. We have a stealth dicer and will be useful for Si detectors.

4. Now we are studying the experiment to design Si detector for the next HEP experiment. And we got following results.

・ In design of edge distance of over 450um, 　　　　　　　　　　　　 the detector can hold over 1000V tolerance, both before and after irradiation.

・ Before irradiation, multi GR （ 2GR,3GR ） holds higher voltage tolerance than single GR

　　　 but after irradiation, the difference between single GR and multi GR tends to disappear.

　　　　　　　　　・ As for GR design, we must consider from viewpoint of both slim edge design and reliability.


We Hamamatsu are proud of the fact that our Si-detectors are being used in many physics experiments.

We are continuously making efforts to provide a better Si detectors.

Thank you for your attention !

Documents

QA Workshop at CERN 3-4 November 2011 2011.11.3 Hamamatsu silicon detectors for high energy physics experiments Kazuhisa Yamamura*, Shintaro Kamada