T owards Sensor Decision for ATLAS IBL

Towards Sensor Decision for ATLAS IBLG. Darbo – INFN / Genova LHCC Upgrade session, 14 June 2011o

Towards Sensor Decision for ATLAS IBL

LHCC Upgrade sessionCERN, June, 14th 2011

G. Darbo – INFN / Genova

Indico agenda:• https://indico.cern.ch/conferenceDisplay.py?confId=141306

https://indico.cern.ch/conferenceDisplay.py?confId=141306

https://indico.cern.ch/conferenceDisplay.py?confId=141306

Towards Sensor Decision for ATLAS IBLG. Darbo – INFN / Genova LHCC Upgrade session, 14 June 20112

Sensors Designs for IBL• Not enough data available to make decision on sensors

Planar: need more measurement with full radiation dose3D: yield and production are the major unknownsBoth: need adequate statistics on irradiated chip-sensor

assemblies

• Following discussion in the IBL community and sensor R&D collaborations, IBL Management and Institute Board decided to restrict the IBL design to two:

• Planar silicon n-in-n, 200µm thickness, slim edge from CiS • 3D silicon, double side, slim edge from CNM + FBK

• To comply with the IBL speedup schedule:• Complete the prototype program while launching

pre-production• Enough sensors (to start module production) will be ready

of the selected technology when decision will be taken

Wafer to be produced (2x good tiles of IBL modules):• CiS: with the measured yield (good statistics available) – 6 batches of

25 wafers satisfy IBL requirements• CNM+FBK: if yield is 50% are necessary 9/10 batches. If yield is 60%

are necessary 8 batches.• Pre-production started: 50 planar (CiS) & 50 3D sensors (FBK + CNM)

CNM/FBK wafer mask8 SC tiles/wafer

CiS wafer mask4 DC tiles/wafer


Sensor Review Sensor review on July 4th and 5th

• Review committee with five ATLAS and two non ATLAS members• The IBL Institute Board with the IBL Management plans to decide on one of the two

sensor technologies based on the reviewers recommendations.• Upon sensor decision, definite IBL MoU and IBL TDR addendum (new schedule) will

be done this summer

Review committee will be asked to evaluate:• Fulfilling the requirements• Look at performance, system issues, production readiness and schedule from

foundries, yield and production quantities, risks and risk mitigation• Give a weighted recommendation based on the information available at the review date

Review Committee:• External reviewers: Gino Bolla (CDF), Petra Riedler (ALICE)• ATLAS internal reviewers: Katsuo Tokushuku (Chair), Craig Buttar, Marko Mikuz, Sally

Seidel, Wladek Dabrowski• ATLAS ex-officio: Beniamino Di Girolamo, Marzio Nessi, Phil Allport,


Sensor RequirementsSensor requirements for IBL (from TDR):

• Radiation Dose: NIEL = 5 x 1015 neq/cm2, TID = 250 MradRequirements from system: The target temperature for operating the IBL sensors is approximately -15 ºC, in order to minimize effects of reverse annealing on the sensors and to avoid thermal runaway

• IBL design uses evaporative CO2 cooling an titanium pipe. • The measured Thermal Figure of Merit (TFoM) is approximately 13 [Kcm2/W], leading

to a sensor temperature of < -20ºC. See simulation in the plot below.

0 5 10 15 20 25-2

0

2

4

6

8

10

12

14

16

IBL temperature and pressure profile. MF=0.8g/s, Tsp=-40ºC, Q=101.8, xend=0.41

Branch length (m)

Del

ta T

(`C

) & D

elta

P(B

ar)

1 2 3 4 56 78 9 10 11 12

Stave TFoM: 13ºC*cm2/W

Pixel maximum temperature:

-24.4ºC

dT Tube wall (ºC)dT Fluid (ºC)dP Fluid (Bar)dT Pixel Chip (ºC)

TFoM Pressure drop ~20%

TFoM Heat transfer ~ 19%

Stave TFoM ~61%

Loaded stave temperature: -24.4°C(0.72 W/cm2)

Unloaded stave temperature: -39°C


Planar Sensor – Slim EdgeIBL selected design the Planar n-in-n technology has→ 200 μm slim edge

Guard rings on p-side are shifted beneath the outermost pixels

→ least possible inactive edge

Less homogeneous electric field, but charge collection after irradiation dominated by region directly beneath the pixel implant

→ only moderate deterioration expected

200µm from pixel to dicing strip~200÷250 µm inactive edge

500µm long pixels~450µm inactive edge

250 µm pixels

Several FE-I4 assemblies made with different thick-nesses (150 & 200µm) and conservative edge (450µm).

No IBL design.


3D Double Side SensorsFBK and CMN have similar process

• FBK full thru columns stopped by membrane. p-spray for pixel isolation

• CNM stop etching before reaching opposite end. p-stop for pixel isolation

• Expected similar performance in IBL, although variations in the two processes.

Same layout and column geometry in both designs• ~10µm column diameter• FBK full through, CNM column tip 15±7µm from

opposite wafer surface.• Production schedule requires aggregate production

700nm DRIE stopping membrane

FBK DRIE:Full thru columns

CNM DRIE:Almost fullthru columns

n+ etched and filled from top

p+ etched and filled from bottom


FE-I4 Assemblies78 FE-I4 single chip assemblies have been bump-bonded at IZM:

• 37 with 700 µm FE-I4 thick chips (no thinning of the wafer)• 36 with 470 µm FE-I4 thick chips (minimum thinning without support wafer)• 5 with 150 µm FE-I4 thick chips + 500 µm glass support (total of 660 µm including ~10

µm glue thickness)Already made assemblies with IBL sensor technologies.

• CiS: 35 of which 10 of IBL design• CNM: 16 of which 16 of IBL design• FBK: 17 of which 9 of IBL design


Irradiation & Test BeamTest beam at DESY (4 GeV electrons) in February and April and at CERN now (180 GeV pions).

• Non irradiated and irradiated samples with proton (Karlsruhe – 25 MeV), and neutron (Ljubljana – nuclear reactor)

• Proton irradiation with devices on PCB – Low proton energy bring high TID (~750Mrad) and ~1÷3 % of pixel dead in the FE-I4

• Bare assemblies irradiated (after test on PCB) in the reactor (activated tantalum by slow neutrons - Ta-182) – reloading on PCB and wirebonding before testing

Quantities we can measure at TB Detection Efficiency

(incl. Edge Efficiency) Charge Collection Efficiency• Spatial Resolution Charge Sharing/Cluster Size• Lorentz Shift

as function of Bias voltage• Threshold setting Incidence angle

measured at DESY

Monitoring available of: Leakage current Sensor temperature

Ref:

J. W

eing

arte

n –

IBL

GM

8 Ju

ne 2

011


Irradiated Samples

Ref: J.Weingarten – IBL GM 8/06/2011IBL General Meeting, CERN 9

Number of samples

Sensor type Design Thickness

(µm)Irrad

FacilityFluence (neq//cm2) Irrad status Status

3x Planar Slim Edge 250 Ljubljana 4.00E+15 irradiated lab- and beam-tested

1x Planar Slim Edge 250 Karlsruhe 3.00E+15 irradiated lab- and beam-tested

1x Planar Slim Edge 150 Karlsruhe 2.00E+15 irradiated lab- and beam-tested

1x 3D FBK-atlas07 230 Karlsruhe 2.00E+15 irradiated lab- and beam-tested

1x Planar Conservative 200 Karlsruhe 5.00E+15 irradiated lab-tested

2x 3D CNM 230 Ljubljana 5.00E+15 irradiated to be wire-bonded and tested

3x 3D CNM 230 Karlsruhe 5.00E+15 irradiated 1x lab-tested2x to be tested

1x 3D FBK-atlas09 230 Karlsruhe 5.00E+15 irradiated to be tested

3x Planar Slim Edge 200 Karlsruhe 5.00E+15 irradiated to be tested

2x Planar Slim Edge 200 Ljubljana 5.00E+15 Irrad planned for today

to be wire-bonded and tested

1x 3D FBK-atlas09 230 Karlsruhe 2.00E+15 irradiated to be tested

1x 3D CNM 230 Karlsruhe 2.00E+15 irradiated to be tested

device irradiated at IBL target fluence AND with IBL design & thickness


Conclusions

Sensor types for IBL reduced to two technologies and designs• Pre-production started for both

Sensor review in place• Decision for sensors in July 2011

Irradiated and non irradiated samples of IBL “designs” available and under test

Definite IBL MoU and TDR addendum this summer after sensor selection


BACKUP SLIDES

Documents

T owards Sensor Decision for ATLAS IBL