ep-dt thin film and glass service (tfg)

•Thin film coating

•Glass & ceramic machining

•Optics Quality Control lab

•Apprentices training (~3*3months)

•General support to DT detector projectsSee link=> https://ep-dep-dt.web.cern.ch/thin-film-glass-service

EP-DT Thin Film and Glass Service (TFG)

Jerome NoelThomas SchneiderMiranda van Stenis Laura Funder (technical student)

More than 50 years growing experience

1DT training seminar T. Schneider 8/4/2020

Florian Jenny(apprentice)

ProductionStandard service

R&D

EP-DT-TFG Location


Optical QC lab(optical spectrometer)

Optical QC lab(Microscopes)

Clean room with 7 coating devices

Offices

Entrance area with ovensand gluing

facility

Building 3 R

Glass and Ceramic

workshop

Entry

Building 108

EP-DT-TFG Infrastructure


Building 3 R

Glass and Ceramic

workshop

Entry

CNC machineBasic glass ceramics cutting facilities

Entrance area

Gluing area ( Fibre beam monitor)

Chemistry and cleaning

Ovens

Turning and milling machine



Clean room preparation areas open for EP-DT and other detector groups

3 laminar flow cabinets for assembly activities (ISO class 7)

Dry nitrogen glove box

Cleanroom assembly area (NA62)

Several Ultra sonic baths

Visual inspection LHCb Muon



Optical Quality Control equipment

Keyence VR3000 3D measurement system

OGP 3D metrology

Different microscopes

UV spectrometer

Perkin Elmer spectrometer for spectral/diffuse reflection and

transmission (200-900nm)HPD/PM QE measurement



PVD thin film coating devices

WLS/Zinc coater

HPD coating plant Small CSI coater Big production coater (1m diameter)

Big CsI coating unit

Generic coating unit (Balzers 1957!)

New state of the art coating unit

EP-DT-TFG infrastructure


List of detector groups or users profiting of our infrastructure (~last 2 years):

• NA62 Giga Tracker (assembly, cleaning and metrology in cleanroom)

• LHCb SciFi (close collaboration)

• SPACAL RD (fibre machining/prototype assembly)

• LHCb Velo (component cleaning/surface metrology)

• LHCb Muon (microscopic chamber inspection)

• CMS HGCal (large silicon sensor cleaning)

• TE-VSC (ceramic machining/spectroscopy)

• CAST –CAPP (repair of turning mechanism for cavity)

• Student workshop (Optics lab of TFG)

• Neutrino platform (PM QE measurements)

• BE-BI (Fibre detector production)

• ATLAS ITk (cleaning/surface metrology)

• DT µ-channel cooling (cleaning/surface metrology)

• DT µ-fabrication facilities (cleaning/surface metrology)• Picosec project with RD51 (machining/handling of photocathodes)

The Perkin Elmer spectrometer (UV-VIS) is used by various CERN users

Open lab?!

EP-DT-TFG PVD coating technology


Motivation for vacuum thin film coating:

• High purity thin layers <=vacuum environment• Low cost of material <=thin layers with same performance as bulk material• Good reproducibility <=precise control of process parameters

Different kind of technologies available:

Physical Vapour Deposition (PVD):Resistive

• Thermal Evaporation (30th)

E-beam

Cathodic• Sputtering (70th)

Magnetron

Chemical Vapour Deposition (CVD)

Thermal vs sputtering

“Thermal evaporation is the more mature technology...it allows coating almost all materials needed for “standard” coating applications”+high flexibility in substrate material andgeometry+Also exotic material can be coated (lowtemp)=>Best candidate for R&D device in TFG lab

-need high vacuum level ( ~10-7mbar)-lower energy coating (packingdensity/adherence)

EP-DT-TFG PVD schematics


concept for uniform large area coating:• Increase distance source –substrate• Rotate substrate • Position source most excentric

Uniformity of layer thickness is key issue

EP-DT-TFG PVD coating application


Optical coatings

• Enhanced reflective coatings• Anti reflective coatings

NA62 RICH UV mirror system

Mylar foil coating for NA62 RICH optical feed trough AR quartz window for LHCb RICH1

Geometer target

Fiber beam monitor



Other light related coatings

• Wavelength shifter coatings (WLS)• Photocathode layers (PC)

Compass Thick-gem PC coating (CsI)

PM wavelength shifter coating (TPB)

Pico-sec (GDD)



Functional layers

• Pre-coating of conductive layers • Transparent conductive layers• De-moulding layers• Zinc layer for isotropic radicals Micro buses de-molding layer (Au)

Conductive layer (Cu) on ceramics

Zinc layer on gold plates for MEDICIS (Medical Isotopes Collection ISOLDE)

Titanium (conductive) spirals on CLOUD UV sabre

EP-DT-TFG Fiber light guide activities


• Construction and installation of ATLAS ALFA detector (initially started with lateral fibre coating)

• Demonstrator construction for AX-PET• Strongly involved in LHCb SciFi development and • Development and construction of 15 Fibre beam

monitors for Neutino Platform (collaboration with BE-BI)

• Contribution to prototype of E-cal LHCb• Individual fibre polishing for various detector

groups (fibre–fin)

Competencies:• Individual fibre polishing• Fibre gluing• Fibre detector construction• Reflective (Al) lateral fibre coating• Fibre end coating

EP-DT-TFG Anti Reflective coating


Improve Transmission of LHCb RICH1 quartz

exit window

A thin transparent layer of MgF2 (n2 different to n1

substrate) is applied via thin film coating to reduce

Fresnel reflection . By setting the thickness of the

coating to a quarter wavelength, the second

reflection R2is delayed by λ

2. This opposite light

wave reduces (cancelation) the initial reflection.

Refractive index n2

Refractive index n1

i r

r’

FRESNELReflection(R)

Refraction

I0

2

12

12

nn

nnR

λ/2

EP-DT-TFG Enhanced reflective coating


λ delay

Enhanced reflective coating

Aluminum as very uniform metallic

reflector is deposited on a polished

substrate. On top a dielectric

transparent layer is applied to enhance

the reflectance of the Aluminum layer.

In this case the layer thickness (~ λ/2)

is adjusted such that the 2nd reflection

is delayed by λ. That way the 2

waveforms overlap and add up.

In addition this dielectric layer act as

protection layer for the Aluminum.

(oxidation and mechanical handling)

EP-DT-TFG LHCb RICH1 upgrade


R&D for LHCb RICH1 optics system (status mid 2019)

• Defined recipe for enhanced protected coating according to given requirements (sensitivity of photo detector 250-500nm)

• Test coating on real size flat mirror (Cr, Al, SiO2, HfO2)

• Overcome intrinsic problem of big spherical mirrors (thinner layers @ borders)

• Test coatings on composite samples

16 flat glass mirrors(370mm*440mm) 4 spherical composite mirrors, (740mm*650mm)

Quartz window QC


The dimensions of the spherical composite substrates have been adapted to the geometrical limits of the coater.These will be the largest mirror substrates ever treated in the TFG lab.

4 spherical composite mirrors, Diagonal 965mm

17DT training seminar J. Nôel 8/4/2020


Big Coater “clean” room B108

Vacuum Tankinner space Ø970 mm

18

E beamPower rack

Process protocolLab view softwareData Acquisition

Cryo pump :Vacuum : 10E-8 mbar

Inficon module :Thickness measurementThermal source processingRotation 60 rpm

DT training seminar J. Nôel 8/4/2020


Rotating substrate holder

X-talThicknessmeasurement

T° sensors

19

Electron Beam source4 crucibles

Thermal sources2 slots :

spring or crucible

Big Coater “clean” room B108


20


LHCB spherical composite mirrors thin film recipe

Adherence layerCr

1st

Metallic reflexionAl

2ndSiO2

3rd

HfO2

4th

Ther

mal

Ther

mal

E B

eam

E B

eam

Enhancement of the reflectivity+ protecting the Al


Dielectric layers with ~30% of thickness variationAt the corners of the big spherical composite mirrors.

Big Coater 108 E beam : relative thickness distribution on a turning substrate

Dielectric layers with 10% of thickness variationAt the corners of the small rich mirror



Big Coater E beam : Thickness variation = reflective variation

Working range of the optical chain is within a wavelength of 275nm - 390nm


22

Small mirrors

Big mirrors

Agreed requirements for Work Package TFG -LHCb RICH1 (EDMS 2060758) 2017Big spherical mirrors:Reflectivity >90% in the range 280nm-380nmSmall flat mirrors: Reflectivity >90% in the range 280nm-500nm


Simulation of the thickness variation on the 4 RICH spherical composite mirrors

10% < Thickness variation < 30%

LHCB Beam pipe center


23

Coater center

Thickness variation < 10%


1- Mask the over exposed areas :Adding a mask in between the E beam and the substrate

Big coater upgrade to make dielectric layers uniform with the E beam on the big substrate


Shaping and sizing the mask.


Precise positioning of the shadow mask for the reproducibility

LED projector Mask Shadow of the Mask


Substrate target

Chrome evaporation's mapping with a fix substrate


2- Electron Beam upgrade for big substrate :


26

Our standard :Small spot

Reducing the border effect and stabilize the beam rate deposition :- Software improvement to position the beam spot with higher accuracy.- Beam spot size optimisation to keep angle distribution most constant during the process.

The walls of the deep groove acts as a mask

To achieve the thickness with the mask we need to do two deep grooves.

Two stepsSpot beam

One stepNEW square beam

Two stepsSpot beam

One stepNEW square beam



Reflectivity measured on samples with all the upgrades

27

Working range of the optical chain is nowwithin a wavelength of 260nm - 500nm

Small mirrors

Big mirrors


Reflectivity > 90% in the range of 270nm to 500nmup to Ø965mm substrate.


As good uniformity results on big spherical as on small flat mirrors!!!

28

Thickness variation < 10%

Achievements of 2019 upgrade with mask and E-beam optimisation:

Small mirrors are ongoing 4 out of 22 are done.We are ready to do the 4 big mirrors


EP-DT-TFG NA62 GTK manufacturing

29

Since 4 years, a part of the TFG Lab is dedicated to the manufacturing of the GTK NA62.



30ar

ou

nd

10

0 s

tep

sDT training seminar J. Nôel 8/4/2020


Example 1 : Sensor assembly gluing on micro channel silicon cooling plate.

Ex 2 : TDCpix and GTK Carrier alignment – Pads 70 µm wide



Operation since 2014 with 3 GTK stations – A 4th station will be added in NA62 on 2021

23 GTK detectors manufactured out of 35 needed by NA62.


EP-DT-TFG Replacement of 2 obsolete generic mid size coater


New state of the art Box-coater

• 2018 EP-DT Budget with some financial support of BE-BI Thanks a lot

• Delivery December 2018• Site Acceptance Test (SAT) march 2019• Commissioning started in summer 2019

EP-DT-TFG new state of the art Box-Coater


Specifications:• Box type process chamber (PC) able to

fit substrates up to 0.5m • Base pressure 10-7mbar• Dry pre-pump (no oil contamination)• Mag Turbo-pump (valve to PC)• Close-loop cooling system• Motor driven rotation (magnetic

coupling) max 8kg and 0-60rpm • Viewport at front door• Exchangeable wall protection liners• Shutters for all material sources• 2 quartz monitor (Inficon) readings• 6 pocket E-gun with sweep option, HV

supply and Controller• 2 Thermal evaporators (2*6KW)• Quartz lamp for substrate heating

Custom build control software for automatic and manual mode

• Automatic pump and vent cycle• Remote software service• PLC controlled installation• PC user interfaceUpgrade 2020• Ion source for in-sito

substrate cleaning

rotation

Turbo pump

pre-pumpcooling

Thermals sources

Inficon

E-gun with shutter

User interface

Viewport

Thickness sensor

EP-DT-TFG Laura

35DT training seminar L. Funder 8/4/2020

EP-DT-TFG Manual Mode


Manual Mode

• Getting to know the machine• The controls• The software• How to start up• How to close down• E-gun

• What is the power of the e-beam?

• Getting to know the materials

EP-DT-TFG Manual Mode


Manual Mode

• Preparation of material• Aluminium• Chrome• Copper• Gold• Quartz• Titanium

• Premelting• Filling up crucibles

little by little• Uniform, melted

material w/o gas enclosures

EP-DT-TFG Premelt


Gold1 – After first meltdown 2 – Refill material

3 – Second meltdown, not successful

4 – Third meltdown, successful

• Boiling point: 2800 ᵒC• Density: 19.32 g/cm3

• Thermal conductivity: 319 W/m*K• %-power: 25%• Graphite crucible• Small e-beam pattern

EP-DT-TFG Premelt


Copper1 – Before meltdown 2 – After first meltdown

3 – After second meltdown 4 – After third meltdown


• Thermal conductivity: 413 W/m*K

• %-power: 22%• Molybdenum crucible• Small e-beam pattern

EP-DT-TFG Premelt


Aluminium 1 – Before meltdown

2 - After meltdown


• Thermal conductivity: 237 W/m*K• %-power: 45%• Wettens easily• Fabmate crucible• Small e-beam pattern

EP-DT-TFG Premelt


Titanium1 – After initial meltdown 2 – Refill material

3 – After first meltdown after refill

4 – After second meltdown after refill


• Thermal conductivity: 24,5 W/m*K• %-power: 60%• Molybdenum crucible• Small e-beam pattern

EP-DT-TFG Premelt


Chrome1 – First fill up of crucible 2 – After first coating

3 – Material grounded and refilled


• Thermal conductivity: 111 W/m*K• %-power: 8%• Sublimation – no liquid phase• Copper crucible• Big e-beam pattern

EP-DT-TFG Initial tests


First Coatings and Initial tests• Inficon thickness monitor• Thickness tests

• Weight tests (EP-DT-EF-TFG)• FIB/SEM tests (EN-MME)• Interferometer (EN-MME-MM)• Veeco Dektak Mechanical

profiler (TE-VSC-SCC)• Bruker Dektak Mechanical

profiler (EPFL - CMI facility)FIB/SEM (EN/MME)

Bruker Dektak (EPFL – CMI) Interferometer (TE-VSC-SCC)

EP-DT-TFG Initial tests


First Coatings and Initial tests• Adhesion tests

• Cross hatch scratch test• Tape test• Pull-off test (TE-VSC)

EP-DT-TFG Automatic Mode


Automatic Mode

• Combine data from manual coatings• Analyze data to find parameters• Test parameters

• Create test recipes• Conduct test coatings• Transmission tests of samples• Analyze results and tune recipe• Repeat until we reach best recipe

View of e-gun during coating

EP-DT-TFG Automatic Mode


Automatic Mode• Safer• More user-friendly• High precision, even for very

thin coatings <2nm• High repeatability• New process

• Stable• Much thinner• Improved uniformity

EP-DT-TFG Study of Cr for RD51-PICOSEC


Study of Cr coating for RD51-PICOSEC

• Study for RD51-PICOSEC

• Aim:

• As transparent as possible

• A level of resistance in the MOhms

• More transmission = more data

• Previous results – 50% transparency

• New results – improve on old results

EP-DT-TFG Conclusion


Conclusion

• Tests in manual mode• Automatic mode

• Study of Cr

• New process• Controlled environment• Highly stable and

repeatable processes• Better precision• Thinner layers

• Future projects

EP-DT-TFG Questions


Questions?

ep-dt thin film and glass service (tfg)

Documents