Atomic Layer Deposition: An innovative approach for next ......Excellent conformality complex geometrical structure, aspect ratio up 1:10 000. Large Palette of available materials
Post on 13-Mar-2021
1 Views
Preview:
Transcript
Atomic Layer Deposition: An innovative
approach for next generation particle
accelerators
Thomas Proslier
15/06/2018
CMSDouble Chooz HESSEdelweiss HerschelALICE
Déchiffrer les rayons de l’Univers
IRFU/Service Page 2
Particle acceleratorsCERN ILC = 17 miles
0
10,000
20,000
30,000
40,000
50,000
1960 1970 1980 1990 2000 2010 2020
Do
llars
per
met
ric
ton
Year
ARIES – PoC 15/06/2018
IRFU/Service Page 3
Atomic Layer Deposition (ALD)
ALD is a thin film synthesis technic based on sequential, self limiting surface chemical reactions between
precursor in the gas phase. It is a layer by layer deposition method.
Pros:
Control at the atomic level of thickness and chemicalcomposition
Films are smooth , continuous, and pinhole free on large surfaces
Excellent conformality complex geometrical structure, aspect ratio up 1:10 000.
Large Palette of available materials
Limits:
Slow growth ~ 1 Å/cy
New materials require new chemistries.
Al2O3 = TMA(Al(CH3)3) + H2O
ARIES – PoC 15/06/2018
IRFU/Service Page 4
Systèmes de dépôts ALD
Cluster tool ~1 M€ Small ALD~ 75k€
Home made ~ 100-150 k€ Temperature ~ TA et 450-500°C
Pression ~ 1 mbar – laminar flow
Neutral gas N2 ou Ar
Précursors: solid, gas or liquid
Substrats: porous, powders, flats…
In-Situ Characterisation:
Thickness (quartz microbalance)
Gas analysis (mass spectrometer)
ARIES – PoC 15/06/2018
IRFU/Service Page 5
In-situ Measurements – ALD Al2O3
Quartz Microbalance
Mass Spectrometry
Discret step growth
1 cycle = Quantum of ALD
Reaction product:
Méthane CH4
Séminaire IRFU – 14/06/2018
Al(OH)*x + Al(CH3)3 -> AlOxAl(CH3)*3-x + x CH4
AlOxAl(CH3)*3-x + 1,5 H2O -> AlO1,5Al(OH)*x + (3-x) CH4
Surface reactions x= 1,5
IRFU/Service Page 6
ALD Al2O3
Séminaire IRFU – 14/06/2018
IRFU/Service Page 7
ALD broad Palette of Materials
See: Miikulainen et al., J. Appl. Phys. 113, 021301 (2013).
Puurunen, J. Appl. Phys. 97, 121301 (2005).
ARIES – PoC 15/06/2018
IRFU/Service Page 8
(LUMINEQ, Beneq Oy, Finland)
R.W. Johnson et al., Materials Today 17, 236 (2014).
ALD - Applications
Microelectronic (high κ thin films): HfO2, Ta2O5, La2O5, Al2O3
Photovoltaïc (Transparent Conducting Oxide): ZnO:Al, InSnO, PbS
Biomedical: TiN, ZrN, CrN, AlTiN
Photonic Crystals: ZnO, ZnS:Mn, TiO2, Ta2N5
Batteries: Al2O3, LaF3, SnF2…
Electroluminescence: SrS:Cu, ZnS:Mn, ZnS:Tb, SrS:Ce
Détectors (MCP’s, gases…)
Catalysis: Pt, Ir, Co, TiO2, V2O5
Thermoelectric: Bi2Se3, Bi2Te3…
Diffusion barrier/anti-corrosion: ZrO2, TiN…
Supraconductors: MoN, NbTiN, TiN…
LED: AlGaN/GaN
Electronique flexible Films diélectrique haut κ
Passivation OLED
ARIES – PoC 15/06/2018
IRFU/Service Page 9
ALD – Applications – Structures
Coating ALD (ZnO) on porous structures: mitigation of charging + enhanced contrast
Electronic microscopy (TEM, SEM)
Tomography (synchrotron) Scientific reports, 7, 5879 (2017)
Self organisation (Block Copolymer)
Advanced Functional Materials, 22, 5129 (2010)
ALD
ALD
JVSTA, 36, 02D403 (2018)
ARIES – PoC 15/06/2018
IRFU/Service Page 10
ALD – Applications – Supraconducteurs
MultiLayers: screening magnetic field for SRF cavities – increase current density JC
Bolometers:
Qubits & quantum computing:
- New superconducting alloys: Nitrides.
- New applications: quantum phase jump junctions,
charge interference junctions, cinetic
inductance…
- Thin superconducting films. Control Tc et de ΔTc
- Cosmological Background Radiation (CMB), dark matter
ARIES – PoC 15/06/2018
IRFU/Service Page 11
Approach 1: Multilayers
A. Gurevich, APL 88, 012511
Fields in bulk Nb cavities approaching dc depairing limit for Nb, Hc(0) ≈ 200 mT
Superconductor-Insulator multilayer [Gurevich, Appl. Phys. Lett. 88, 012511 (2006)] Increase performance
– Move beyond limits of Nb Decrease cost
– Higher operating temperature (reduce cryogen costs)– Replace bulk Nb with cheaper material (Cu/Al)
Coat inside Nb SRF cavity with precise, layered structure → ALD
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 12
ALD – Applications – Supraconducteurs
Niobium Carbide: NbC 1.7 K
Niobium Carbo-Nitride: NbC1-xNx 3.8 K
Niobium Silicide: NbSi 3.1 K
Titanium Nitride: TiN 3.9 K
Molybdenum Nitride: MoN 12 K
Niobium Titanium Nitride: Nb1-xTixN 14 K
NbSi - épaisseur
NbTixN - Composition
MoN - épaisseur
ARIES – PoC 15/06/2018
IRFU/Service Page 13
MoNx ALD: Tc vs. thickness
Tc = 9.25 KΔNb = 1.55 meV
15nm
18 nm
20 nm
30 nm
60 nm
Thickness > 50 nm
ARIES – PoC 15/06/2018
IRFU/Service Page 14
MoNx ALD: MoCl5 and NH3 – Epitaxy ?
Al2O3
MgO
MoN
TEM: C. Alvarez (ANL/NU)
ARIES – PoC 15/06/2018
IRFU/Service Page 15
60 nm MoN
Klug, Becker, et al., Appl. Phys. Lett. 103, 211602 (2013).
Electrical Properties
ARIES – PoC 15/06/2018
IRFU/Service Page 16
ALD on Nb cavity - superconductors
Deposition at temp. > 250°C for10 hr to 48 hr on Nb metal require an UHV environment
HV Oven : 10-8T a 500 0C
Automatic growth process
4 solid precuror lines HT (250°C)
1 precursor line UHT (500°C)
4 precursor lines gases/liquids
RGA analysis
ARIES – PoC 15/06/2018
IRFU/Service Page 17
Eacc [MV/m]
NbTiN/AlN
ALD multilayer NbTiN(50 nm)/AlN(10 nm) 450°C – 10 hrs
ALD
ALD multilayer MoN(80 nm)/AlN(10 nm) 450°C – 10 hrs
1,00E+08
1,00E+09
1,00E+10
0 2 4 6 8
2…3…
Eacc [MV/m]
2 K
3.5K
MoN/AlN
ALD on Nb cavity - superconductors
ARIES – PoC 15/06/2018
IRFU/Service Page 18
Approach 2: Doping + protection
Dissociate influences: doping vs. oxide
Gases:
- Nitrogen < 300°C et PN2 ~ 10-2 mbar
- oxide growth: O2, NO2, CO2
à T ~ 100-150°C et PX ~ 10-2 mbar
Other dopants (?)
- Layer deposition: NbN, TiN, MgO,
Al2O3, Y2O3 … thickness ~ 5 nm
- Annealing (diffuse O far into bulk butkeep metal cations within λ: Al, Mg, Y, Ti, …)
ARIES – PoC 15/06/2018
IRFU/Service Page 19
ALD on Nb cavity: Dielectrics
10 nm Al2O3 (90°C – 1 hr) 2 nm Al2O3 / 15 nm Nb2O5(250°C – 2 hr)
15 nm Al2O3(250°C – 2 hr) + 450 °C/20 hrs
Remplace Nb2O5 by another more stable oxide: l’Al2O3
Diffusion/decomposition of Nb2O5 into bulk Nb to create a clean
interface.
ARIES – PoC 15/06/2018
IRFU/Service Page 20
Hc2(0) → x(0) = 5.7 ± 0.1 nm
ALD applications for particle accelerators: Superconducting Magnets
Assume λ ~ 200 nm, estimate JD(0)~1×108 A/cm2; Jc(0) ~ 107 A/cm2
For MoN (d = 60 nm) on 50 µm Cu wire, IMAX ~ 1,5 A; IMAX(2K) ~ 1,3 A
H
𝑗𝑐 = 𝐻𝜋 𝑟
𝐿𝑛( 8 𝑟 𝑑 − 0.5)𝑤. 𝑑
ARIES – PoC 15/06/2018
IRFU/Service Page 21
Copper magnet
Cu/MoN(1000cy)/AlN(300cy) at 450°C : 200 wires/ 50 µm diameter
Conformal Deposition
– Multilayer SIS
JC EXP ~ 10% de JD,
IMAX ~ 260 A per layer at 2 K
ARIES – PoC 15/06/2018
ALD applications for particle accelerators: Superconducting Magnets
IRFU/Service Page 22
ALD Other applications for Particle accelerators
ARIES – PoC 15/06/2018
3D printing + ALD: beamlines optics (Fresnell, kinoform Lenses and capillaries):
W ALD + PMMA
Charging of ceramics: mitigation by TiN thin film (2-5 nm) on ceramic windows (coupler)
Detectors (MCP’s): controlling resistivity by doping W:Al2O3 + high SEE layer MgO
Diffusion barriers or adhesive layers: Nb3Sn/Cu or Nb/Cu > 400°C – TiN/AlN on Cu.
Low secondary electron emission film ~ nm thick of carbide, nitrides…amorphous Carbon?
IRFU/Service Page 23
Where are we?
Laboratory set up (gases…).
ALD system: Setting up, Chemistry part is ready, Funding for Oven approved (85 k€) and ordered,
reception in 4 months. Missing: RGA, turbo pump + small dry pump + conn cavity – ALD.
ALD Doping: Oven for post-annealing up to 1200°C – qualified for cavity use.
Transport + Tunneling spectroscopy connected…proposal submitted for a Faraday cage (75 k€).
Magnetometry of C. Antoine working full speed. Upgrade to reach higher fields completed – 150 mT.
PANAMA: characterisation platform for particle accelerators.(SIMS, X-Ray). Need for better SIMS.
2 Nb cavities with good performance (Q = 1.5 1010 at 35 MV/m Quench at 37 MV/m) – EP ninja.
Missing: 1 more for doping.
Effort-Support: C. Antoine, Technician Aurelien Four + 1 PhD student. RF tests – cavity prep.
ARIES – PoC 15/06/2018
IRFU/Service Page 24
Timetable-Deliverable
WP\T T1 T2 T3 T4 T5 T6
WP1-D1
WP2-D2
WP2-D3
WP2-D4
WP3-D5
WP3- D6
WP3-D7
WP1:
D1 – ALD system commissioning
WP2:
D2 – Deposition High Quality superconducting film on Nb samples
D3 – Optimization of screening efficiency on Nb samples
D4 – Deposition of optimized mutlilayers (MoN and NbTiN) on two Nb cavities
WP3:
D5 – Deposition of MgO, Y2O3 and Al2O3 films on Nb samples
D6 – Optimization of dopant concentration profile for MgO, Y2O3, Al2O3 films
D7 – Deposition of selected film and post annealing treatment on Nb cavity
ARIES – PoC 15/06/2018
IRFU/Service Page 25
Budget
Items Description Cost (k€)
1 Niobium cavity 1.3 GHz Tesla Design 10
2 TOF-SIMS: Depth profile O + metal cations – 12 samples 6
3 ALD System oil pump (Neyco) 6
4 ALD System RGA 15
5 Adaptation flanges cavity – ALD system 3
6 ALD gas purifiers 4
7 Precursors 5
8 Shipping samples/cavity CERN – CEA 1
Total 50
ARIES – PoC 15/06/2018
IRFU/Service Page 26
Partnership
Industry - ALD:
- CEA and AirLiquide Non-Disclosure Agreement (NDA) on new precursor synthesis
and 3D printing of Cu, Ti, Nb, Al pure metals.
- AirLiquide agreed to provide ~ 200 gr of new precursors of Nb, Mo and Mg.
-> first prove that ALD is working prior to more investment.
- Talk scheduled in September at AirLiquide
-> prepare for next round of AirLiquide internal funding decision
- CEA-Tech: Start up Incubator. + Paris-Saclay: IncubAlliance.
Collaborations:
CERN
- Transport, magnetometry,Tunneling spectroscopy for Nb/Cu or Nb3Sn/Nb and Nb3Sn/Cu
- Cavity tests …
DESY:
- Tunneling spectroscopy and X-Ray diffraction, SEM…
IPNO-LAL
ARIES – PoC 15/06/2018
Direction de la Recherche Fondamentale
Institut de recherche
sur les lois fondamentales de l’Univers
Commissariat à l’énergie atomique et aux énergies alternatives
Centre de Saclay | 91191 Gif-sur-Yvette Cedex
Etablissement public à caractère industriel et commercial | R.C.S Paris B 775 685 019 Service
THANKS !
IRFU/Service Page 28
Summary - Epitaxy
High quality epitaxial IV-VI nitrides synthesized by atomic layer deposition at modest temperatures
(450°C).
Films on a-Al2O3 show superior electrical and superconducting properties compared to those grown
concurrently on amorphous SiO2.
Klug, Becker, et al., Appl. Phys. Lett. 103, 211602 (2013).
ARIES – PoC 15/06/2018
IRFU/Service Page 29
Molybdenum nitride
d-MoN (P63mc) g-Mo2N (Fm3m)_
Crystal structures: Bull, et al., J. Solid State Chem. 177, 1488 (2004); Bull, et al., J. Solid State Chem. 179, 1762 (2006)
Tc = 12 K Tc = 5.2 K
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 30
Linear, well controlled growth with fine thickness control
Bulk-like density, roughness 25-35 Å
Growth temperature: 450 0C
MoCl5 + NH3 - AlN : AlCl3 + NH3
Molybdenum Nitride (MoN)
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 31
MoNx ALD: Tc vs. thickness
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 32
HALL MEASUREMENT
Carrier concentration
𝑘𝐹 = (3𝑛𝜋2) 1 3
𝑙 =𝑘𝐹 . ℏ
(𝑛 𝑒2 𝜌)
𝐷 = −4𝑘𝐵 𝑑𝑇𝑐 𝑑𝐻
𝜋 𝑒
𝜏 =𝑙2
3 𝐷
𝑚𝑒𝑓𝑓 = 𝑚𝑒
ℏ. 𝑘𝐹𝑉𝐹
𝑉𝐹 =𝑙
𝜏Dirty limit: ξ > l
Transition:
Strong disorder kF.l~1 to kF.l >> 1
meff = 6.4 me
MoNx ALD: Hall effect vs. Thickness
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 33
MoNx ALD : XPS - Composition vs. thickness
Composition: MoN 1:1 + Nucleation as Mo2N
Sputtering change stoichiometry from MoN to Mo2N
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 34
MoN (0001) Mo2N (111) Al2O3 (0001)
MoNx Density Functional Theory
MoN/Al2O3 Mo2N/Al2O3 MoN,int – Mo2N,int
m(N,NH3) @ 298K,0.1MPa m(N,NH3) @ 673K,0.1MPaDFT shows that: Mo2N is more favorable on C-Plan and MoN is preferred on R-Plan
Confirm the trend seen experimentally
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 35
Summary
Tune Tc and transport properties by controlling film thickness
Tune Tc and transport properties by controlling composition: Nb1-xTixN, TiN, MoN,
NbSi, NbC, NbCN ...
Growth temperature : lower Temp for High quality nitrides
Fundamental interest for Quasi 2D limits + applications: Bolometers, High
energy physics accelerators, magnets…
Future work: MgB2 (40K), FeSeTe (15K), K(FeSe)2 (31K) etc… More cavity
coating/Testing
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 36
Synchrotron tools
Synchrotron techniques offer a suite of probes sensitive to atomic-scale structural and chemical
information.
By applying synchrotron measurements in situ to study ALD processes, we can investigate the evolution of
crystallinity, microstructure, morphology, and chemical composition in the crucial early stages of film
growth.
ALDALD
Crystallinity
Microstructure
Morphology
Composition
Séminaire LMGP-Grenoble 24/11/2016
IRFU/Service Page 37
MoNx ALD: Application ?
TiN(7.5 nm)/MoN(50nm) at 450°C
SQUID
ARIES – PoC 15/06/2018
38
Nb1-xTixN: Superconducting Tc
Achieved superconducting Tc=14 K 4:1
– 40% higher than previously reported value for ALD NbN
[Hiltunen et al., Thin Solid Films 166, 149 (1988)]
Δ = 2.3 meV +- 0.1
T= 1.8K
50 nm NbTiN film
top related