18.7.2003General Tracker meetingA. Furgeri 1 Irradiation results and Annealing scenarios for HPK IEKP – University of Karlsruhe Alexander Furgeri [email protected]

18.7.2003 General Tracker meeting A. Furgeri 1

Irradiation resultsIrradiation resultsand and

Annealing scenarios for HPKAnnealing scenarios for HPKIEKP – University of Karlsruhe

Alexander Furgeri

[email protected]


OutlineOutline

• Overview of relevant sensor parameters

• Main results from p-irradiation

• prequalification W1TID-, IB1- and W3-Wafers for irradiation in Louvain

• Results from irradiation in Louvain

• Scenarios of Udep for inner Barrel sensors

• Conclusions


Parameters of sensorsParameters of sensors

Resistivity: expected to be <2kΩcm>varying from 1.25 to 3.25kΩcmµeNeff

1

Full depletion voltage:

Effect of thickness: 320µm 290µm (30µm n+-layer) ~19% less depletion voltage !

22 dNU effe

dep

Higher resistivity lower depletion voltage

For allowed range of resistivity: 130V < Udep <350V

ADeff NNN


Differences diodesDifferences diodessensorssensorsThe depletion voltage for sensors are also depending from geometrie factors.

pw

dp

diodesensor fUU 21* 316.0pwf

The lowest is : ~1.16 (IB1)The highest is : ~1.31 (W3) Only HPK!


Changes of Rpoly after irradChanges of Rpoly after irrad

0 10 20 30 40 501,0

1,2

1,4

1,6

1,8

2,0

2,2

before irrad after irrad

Rp

oly

[M]

strip number0 10 20 30 40 50

1,0

1,2

1,4

1,6

1,8

2,0

2,2


Rp

oly

[M]

strip number

+ 0.35 MΩ+ 0.15 MΩ

n-doped poly-Si Increase of Rpoly due to donor removal

HPK with high fluence ST with low fluence


Changes of CC after irradChanges of CC after irrad

0 1 2 3 4 5 6 7 8 93,20E-010

3,30E-010

3,40E-010

3,50E-010

3,60E-010

3,70E-010

3,80E-010

3,90E-010

4,00E-010

4,10E-010


Co

up

ling

ca

pa

cita

nce

[F]

strip number

- 15pF

HPK –sensor with high fluence

For minis ~ -1pF,Difficult to see due to fluctuations of measurements with100Hz.


Results from proton irradiationResults from proton irradiation

• Small increase of Rpoly• small decrease of CaC• small increase of Cint (for allowed flatband voltage range! Defined from studies in KA)• Rint above limit (introduced measurement signal below noise)• NO PINHOLES !!! • NO LEAKY STRIPS !


Development of UDevelopment of Udepdep

Changes of Neff:

– short term annealing

– stable Damage

– long term reverse annealing

),()(),(),( tNNtNtN eqyeqceqaeqeff

iaieqeqa

it

egtN ),(

eqcc

effceqc geNrN eq )1()( 0,

)1(),(1

1,

ytyeqy NtN

1 Depeff UN

1 10 100 1000 10000 100000 1000000

-4

-2

0

2

4

6

8

10

12

14

16

18

Annealing @ 60°C and =2.5e14n/cm2

Nef

f [1

012cm

-3]

Time [min]


Experimental data for donor Experimental data for donor removal in Hamburg modelremoval in Hamburg model

0,0 0,5 1,0 1,5 2,0 2,5 3,00

50

100

150

200

250

300

350

400

Fit parameters:g

c=1.49e-2 /cm

rc=0.65

c=10.9e-2/N0g

a=1.81e-2 /cm

ta=19 min

gY=5.16e-2 /cm

tY=1260 min

320µm minisensors: r

c=0.65

rc=0.8

rc=0.5

Ful

l dep

letio

n vo

ltage

in V

Fluence in 1014 n1MeV

/cm2

HPK with high fluence

rC=NC,0/Neff,0

Describes complete or partial donor removal

rC <1 !

Results from KAp-irradiation


Special n-irradiation (high res.)Special n-irradiation (high res.)

• Irradiation in Louvain of IB1,W3 & W1TID– Check for resistivity profile across wafer,

(before irradiation)– Check if sensors follow the Hamburg model !– Adjusting parameters and taking into account

for scenarios– Check of new measurement methods of

Louvain (Rpoly!) and cross check with Karlsruhe


Resistivity explained by HPKResistivity explained by HPKHPK delivered sensors withto high resistivity.Explanation from HPK:Wafers have a large variationof resistivity across waferprofile! But also sensors with a resistivity of >5kΩcm (70V)appeared in the community.

Question: where does

the depletion voltage end?


Prequalification W1TIDPrequalification W1TID• Diodes 2-5 and 10-13 not measurable• breakdown for diodes between 460V and 530V• depletion voltage for diodes: 50V (for all !)• depletion voltage for minis: 80V (~1.3*Udep of diodes ?!)• Depletion voltage for sensor 105V (profile of HPK seems to be right)• Same profile for W3


0,00E+000 1,00E+014 2,00E+014 3,00E+0140

50

100

150

200

250

300Diodes for all geometries

rc=0.3 for init. Udep

=50V rc=0.3 for init. U

dep=64V

rc=1 for init. Udep

=64V rc=1 for init. U

dep=50V

rc=0 for init. Udep

=64V rc=0 for init. U

dep=50V

exp. data

de

ple

tion

vo

ltag

e [V

]

fluence [1MeV-n/cm²]

Irradiation in LouvainIrradiation in Louvain

rc~ 0,3 (0.65)gc~ 1,2e-2 (1.49e-2)

Only diodes choosen foradjusting the hamburg model!Reason: variation in correctionFactors diodes↔Sensors due to resistivity profile!



0,00E+000 5,00E+013 1,00E+014 1,50E+014 2,00E+014 2,50E+014 3,00E+0140

50

100

150

200

250

300Minisensors (divided by corr. factor)

model for 62V model for 99V exp. data for 62V exp. data for 65V and 73V exp. data for 99V

de

ple

tion

vo

ltag

e [V

]


Check if minisensorsfollow the HamburgModel with the new exp. data!



0,00E+000 1,00E+014 2,00E+014 3,00E+0140

50

100

150

200

250

300Real sensors (divided by calculated correction factors)

exp. data model for diode values (63V) model for diode values (72V) model through exp. data (63V) model through exp. data (72V)

de

ple

tion

vo

ltag

e [V

]


Check if sensors followthe Hamburg model!gc~1.1e-2 ? rc~0.3 !


Cross check LouvainCross check Louvain KA KA

Sensor IDbefore after before after before after before after

fluence (n/cm 2̂)Vdep (V) 93,44 28 93 99 81,91 230 110,57 360

leakage current (nA) 10924 9,47 20410 16,68 45684 983800<Rpoly> (Mohm) 1,52 1,77 1,53 1,82 1,51 1,71 1,61 /

<Cint> (pF) 0,62 0,62 0,64 0,67 0,64 0,61 1,27 2,78<Rint> (Mohm) >2000 >2000 >2000 >2000 >2000 >2000 >2000 83

<Cac> (pF) 69,4 64,74 70,6 69,5 69 68,6 368 259,2Pinholes? 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10

Bad strips ? 0/10 0/10 0/10 0/10 0/10 0/10 0/10 0/10

Qualified?

30221525000101_baby

OK

30221525000101_sensor

OK

2,41E+14 3,10E+14

30221525000110_baby

OK

30221525000127_baby

OK

5,87E+13 1,41E+14

Very good agreement for minisensors !For sensors discrepances in Cint and CC!


Batches with high resistivityBatches with high resistivity

• HPK delivers sensors with high resistivity– higher depletion voltage in the end of CMS expected– Luminosity in the tracker

• 1. year 10%• 2. year 33%• 3. year 67%• 4.-10. year 100%

– Sensor fluence in reality depending from the location in the tracker

• Radial location (especially for charged Hadron fluence)• Z-location (especially for neutron fluence in the endcaps)


Fluence distribution in the Fluence distribution in the trackertracker

Low variation in fluence formost geometries.

geometry Fluence [10e14-1MeV]

Charged Hadrons / neutrons

IB1 – 1. Layer IB1 – 2. Layer 1.26 / 0.33 0.67 / 0.32

IB2 0.4 / 0.2

W1TID 1.02 / 0.35

W1 1.02 / 0.35

W2 0.65 / 0.4

W3 0.4 / 0.6 - 0.22 / 0.6

W4 0.3 / 0.32 - 0.2 / 0.6

Uncertanties in fluences: 50%


Calculation of the scenarioCalculation of the scenario

• Local Distribution of fluence in the Tracker– Tracker-TDR

– comparison with E. Migliore (same source ?!)

• Fluences for different geometries• Per year:

1. Irradiation (at once)

2. Beneficial annealing (10°C & 20°C)

3. Reverse annealing (10°C & 20°C)

• Scenario for 10 years• time without beam and annealing not shown


Time constants for HHTime constants for HH

For +20°C: τA=2.3 daysτy=475 days

For +10°C: τA=10 days τy=2920 days

For –10°C: no significant change for 10 years

To avoid reverse annealing keep temperature as low as possible!


Differences Differences A. FurgeriA. Furgeri E. Migliore E. Migliore

• A. Furgeri– 28 days per year @ 20°C

• 5 Times higher time constant for beneficial annealing

– Donor removal (rC) from experimental data in Karlsruhe and Louvain (better for low resistivities, less uncertainties)

– gc from exp. data– Geom. factors for sensors,

confirm with exp. Data– Factor of 1.5 for fluences

• E. Migliore– 28 days per year @ 10°C

• 26 times reduced time constant for reverse annealing

– Complete donor removal for hadron fluences (worse for low resistivity, but not confirm with exp. data)

– gc from literature– No correction factor (diodes

instead of sensors)– No factor for uncertainties

in fluences


What‘s the allowed maximum What‘s the allowed maximum for depletion voltage?for depletion voltage?

• Max. 600V from power supplies• Factor of 1.5 for over depletion neededMaximum for depletion voltage of 400V ?!

Let‘s look where we are !


Description for following plotsDescription for following plotsIrra d ia tio n

Anne a ling

Irra d ia tio nAnne a ling

Irra d ia tio n


Anne a ling

Before type inversion After type inversion


N o run (-1 0°C )


N o run (-1 0°C )

Real scenario


Scenarios IB1 – 1. LayerScenarios IB1 – 1. Layer

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800

Maximum voltage of power supply

Limit for sensors

ch. Hadrons

=1.5*1.26e14

neutrons =1.5*0.33e14

1.25 kOhmcm 2kOhmcm 3.25kOhmcm 4kOhmcm 5kOhmcm

dep

leti

on

vo

ltag

e [V

]

years [y]

Worst case for IB1,thickness 320µm,Annealing @20°C 14 days,Maximum 440V

With actual thickness of 290µm: 360VRemember Udep~ d²Effect of higher resistivity: ~30V


Scenarios IB1 – 1. LayerScenarios IB1 – 1. Layer

Worst case for IB1,with thickness 320µm,28 days @20°C per yearMaximum 530V

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.26e14



dep

leti

on

vo

ltag

e [V

]

years [y]

With actual thickness of 290µm: 435V


Scenarios IB1 – 1.LayerScenarios IB1 – 1.Layer

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.26e14



dep

leti

on

vo

ltag

e [V

]

years [y]

Worst case for IB1,with thickness 320µm,28 days @ 10°C per year

d= 290µm 320V


Scenarios W1 TEC & TIDScenarios W1 TEC & TID

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.02e14



depl

etio

n vo

ltage

[V]

years [y]

14 days @ 20°CMaximum 400V


0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.02e14



dep

leti

on

vo

ltag

e [V

]

years [y]

d= 290µm 380Vd= 290µm 320V


Scenarios IB1 – 2.LayerScenarios IB1 – 2.Layer

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*0.67e14



dep

leti

on

vo

ltag

e [V

]

years [y]



0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*0.67e14



dep

leti

on

vo

ltag

e [V

]

years [y]


Scenarios W2Scenarios W2

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*0.65e14



dep

leti

on

vo

ltag

e [V

]

years [y]



0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*0.65e14



dep

leti

on

vo

ltag

e [V

]

years [y]

d= 290µm 315V


Sceanrios W3Sceanrios W3



0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*0.4e14



dep

leti

on

vo

ltag

e [V

]

years [y]

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*0.4e14



dep

leti

on

vo

ltag

e [V

]

years [y]

d= 290µm 250V


Different donor removalDifferent donor removalin worst case scenarioin worst case scenario

Donor removal of 65% for ch. Hadrons and 30% for neutrons, due to exp. data

Complete donor removal for ch. Hadrons and 65% for neutronsNot confirm with exp. data

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.26e14



dep

leti

on

vo

ltag

e [V

]

years [y]

Effect of 40V for high res. 100v for low res.

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.26e14



dep

leti

on

vo

ltag

e [V

]

years [y]


DiscrepancesDiscrepancesIQC and ScenariosIQC and Scenarios

Result after IQC (no exp. data!) No reverse annealing!

0 1 2 3 4 5 6 7 8 9 100

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.26e14



dep

leti

on

vo

ltag

e [V

]

years [y]

0 1 2 3 4 5 6 7 8 9 10 11 12 13 140

100

200

300

400

500

600

700

800


Limit for sensors

ch. Hadrons

=1.5*1.26e14



dep

leti

on

vo

ltag

e [V

]

annealing time [d]

Scenario for IB1- 1.LayerEffect of reverse annealing ~200V!


Summary of uncertaintiesSummary of uncertainties• Donor removal ? Irradiation in Lubljana in progress (9

minis) for different fluences. (higher statistic)

• Temperature during shutdown and repair periods ?

– CONDITIONS CONTROLLED ?!

– Avoid reverse annealing ! Try to keep temperature below 20°C ! max. of +10°C for 4 weeks?!

• Time of shutdown and repair periods ?

– Open (warm up) the Tracker as late as possible !

• Fluences in different running periods ?

• Effectiv thickness of sensors ? Changes in production?

• … Ask me again after 10 years!


ConclusionsConclusions• Worst case for IB1,(W1TEC & W1TID?) needs

~700V bias voltage, but expected to be better• Separation of sensors with different resistivities

possible for IB1 (1. & 2. Layer) • No separation possible for W1 and W1TID• IB2,W2,W3 & W4 not critical (high res.

accepted)• Question of high resistivity: Sensors accepted,

with compromise, that the next sensors of IB1 will have a lower resistivity (1.25-2 kOhmcm)

Documents

18.7.2003General Tracker meetingA. Furgeri 1 Irradiation results and Annealing scenarios for HPK IEKP – University of Karlsruhe Alexander Furgeri [email protected]