Thin Film Coating Using

Cathodic Arc

Irfan Irfan Alameda Applied Sciences Corp. San Leandro (the SF Bay Area), California

`

This research is supported at AASC by DOE SBIR Grants DOE Grants: #DE-SC0011371, DE-SC0011294,

DE-SC0007678, DE-SC0004994 and DE-SC0009581

At Department of Chemistry IIT-Delhi on 10 February 2015

Small R&D firm, started in

1994 by Dr. Mahadevan

Krishnan.

Since inception main focus

has been the application of

Pulsed Plasma Technology.

Funded substantially by

different government

contracts.

Alameda Applied Sciences Corporation:

Limited success in past

commercialization

attempts.

Currently more focused on

SRF coatings and fast gas

valves for LPA.

Alameda Applied Sciences Corp. Contd.:

Cathodic Arc Coating (Ion Energy):

Comparison of Stress build-up in low energy deposition, energetic condensation, and energetic condensation plus high voltage bias

[*] M. M. Bilek, R N. Tarrant, D. R. McKenzie, S H. N. Lim, and D G. McCulloch “Control of Stress and Microstructure in Cathodic Arc Deposited Films” IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 31, NO. 5, OCTOBER 2003

(A. Bendavid, CSIRO)

(M.M. Bilek)

* A. BENDAVID, P. J. MARTIN, R. P. NETTERFIELD, G. J.

SLOGGETT, T. J. KINDER, C., ANDRIKIDIS, JOURNAL OF

MATERIALS SCIENCE LETTERS 12 (1993) 322-323

Ion energy, eV

f(e)

Nb

Energetic Condensation (Crystal Growth):

In Energetic Condensation, the ions deposit energy in a sub-surface layer (≈3-5 atomic

layers deep for ~100eV Nb ions), shaking up the lattice, causing adatom mobility and

promoting epitaxial crystal growth

Energetic Condensation, when combined with substrate heating, promotes lower-defect

crystal growth

J.A. Thornton, "Influence of substrate temperature and deposition rate on the structure of thick sputtered Cu coatings”, J. Vac. Sci.

Technol. Vol. 12, 4 Jul/Aug 1975

Andre Anders, A structure zone diagram including plasma-based deposition and ion etching, Thin Solid Films 518 (2010) 4087–4090

~30-100 V applied between a desired cathode and an anode mesh.

A triggering event at one side initiates one pulse of coating.

Averaged over many pulses it creates a uniform ~1 monolayer/pulse coating.

Coaxial Energetic Deposition:

Coaxial Energetic Deposition (CEDTM)

SRF Coating Requirements:

Test Why

Film ADHESION with frequent cooling

and heating: Thermal Shocks

For operation at 2-4 oK

Film ADHESION with >500 psi water

rinse: Mechanical Shocks

To remove particulates and secondary

ion emission sites

Film ADHESION with: Mechanical

Flex

For connecting RF cavities/cells

(stainless steel bellows)

High Crystalline growth: High RRR For acceleration gradient in >1010

eV/m (no quenching) => Low

resistance (BCS limit and low defects)

Compatibility with Complex

Geometries

For coating real accelerator hardware,

RF cells, Power Couplers

In Liquid nitrogen bath multiple times.

Tested at AASC

Thermal Shock:

In Liquid nitrogen bath multiple times.

Tested at Brookhaven National Lab by J C Brutus, B. Ping, and Y. Huang.

Thermal Shock on Bellows:

CERN Resonator Plate-1:

The film came off at

~8 bars (~60psi)

High pressure water rinse (HPWR) on ~3 mm thick12 mm x 50 mm bars.

All survived well beyond 500 psi.

Tested at Fermi Lab by Curtis Crawford

Mechanical Shock:

CERN Resonator Plate-II:

5 min. in a 20g/l sulfamic acid -> 20 min. rinse in distilled water -> in IPA bath till mounting.

3.4 micron film at center and ~2 around edges.

Survived ~80 psi at CERN, tested by Sarah Aull.

The Nb film survived repeated cycles of HPWR at up to (80Bar) 500psi.

Tested at Los Alamos N Lab by T. Tajima

Nb Coated Cu 1.3 GHz Cell:

KEK-06 Cu cavity before Nb coating KEK-06 Cu cavity after Nb coating

Mechanical Flex on Bellows:

Starts in Expanded position 3.5”

Compressed to 2.6” in 1 sec,

stays 0.5 sec

Back to expanded position in 1

sec, stays 0.5 sec

24,000 times (~20 Hrs)

Rinsed, filtered and analyzed for

particles that may come off

during the mechanical flex test

Tested at BNL by Bin Ping et al

High RRR films:

HPWR 500 psi at FNAL, RRR≈52 in our Cu films

Temple Univ. measured AASC Cu on SS strips RRR~42 – 64

XFEL Germany requirements >30

Stainless steel tube coated with a ~28µm

Cu film using the AASC CED process

Copper surface after 86Bar HPWR test

(courtesy of Curtis Crawford/FNAL)

High RRR on coupons motivates coating accelerator structures

RRR-585 measured on 5µm

film on MgO

RRR-330 measured on a-

sapphire

M Krishnan, E Valderrama, B Bures, K Wilson-Elliott, X Zhao, L Phillips, A-M Valente-Feliciano, J Spradlin, C

Reece and K Seo, “Very high residual-resistivity ratios of heteroepitaxial superconducting niobium films on MgO

substrates,” Superconductor Science and Technology , vol. 24, p. 115002, November 2011

M. Krishnan, E. Valderrama, C. James, X. Zhao, J. Spradlin, A-M Valente Feliciano, L. Phillips, and C. E. Reece,

K. Seo, Z. H. Sung, “Energetic condensation growth of Nb thin films”, PHYSICAL REVIEW SPECIAL TOPICS -

ACCELERATORS AND BEAMS 15, 032001 (2012).

110 & 200 200 110

Polycrystalline

Monocrystal

with two

orientations

Monocrystal

with 100

orientation

RRR=7, 150/150 RRR=181, 500/500 RRR=316, 700/700

Change in crystal

orientation from 110 to 200

at higher temperature

RR

R

RR

R

Compatibility with Complex Geometries:

Coating inner surface of bellows.

Coating outer surface of tubes.

Coating inner surface of long tubes.

HPWR 500 psi at FNAL all survived except the

tube coated outside.

RF test of Nb Film:

Nb coating on 2” Cu single crystal.

RF measurement by Paul Welander at SLAC-Stanford.

Current State of the Art Bulk Nb:

N doped bulk Nb cavities from FNAL.

AASC Nb coating on KEK06, RF measurements by T. Tajima at LANL.

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

0 2 4 6 8 10

Q0

Eacc(MV/m)

4K

<2K

Thank You AASC

Mahadevan Krishnan,

Steven Chapman,

Katherine Velas Los Alamos N. Lab

Tsuyoshi Tajima.. CERN

Sarah Aull..

Fermi Lab

Curtis Crawford,

Lance Cooley..

Brookhaven N. Lab

Sergey, Bin Ping..

Jefferson Lab

Rong Li, C. Reece…

Argonne N. Lab

Thomas Prolier..

SLAC (Stanford)

Paul Welander..

SLAC (Stanford)

Xiaoxing Xi..