Plasma, electron and ion beams surface patterning of metals

T. Czerwiec, G. Marcos

Institut Jean Lamour (IJL), Ecole des Mines de Nancy, Parc de Saurupt, CS 14234, 54 042 Nancy, France.

Plasma, electron and ion beams surface patterning of metals

Stanislas place in Nancy

Jacques Callot (c. 1592 – 1635) was a draftsman that was working in Nancy and important figure in the development of the old master print (engraving,

etching…)

http://www.ijl.nancy-universite.fr/

Introduction what is patterning and why surface patterning?

Strategies for creating surface patterns

Photolithography

Advanced serial mask-less processes

Additive parallel processes with masks (templates)

Removal serial and parallel processes : energy beams

Moving parallel processes : patterning by nitriding

Last experiments done on combining stainless steel patterning by

photolithography and nitriding

Conclusion

Introduction: what is surface patterning?

Surface patterning, also known as surface texturation or surface structuration is a part of surface engineering that consists in the production of a "patterned" surface

with some regular array of surface height features on the size scale of several micrometers to some nanometres

NbOx nano-pilar with a mushroom-like shape prepared by using ultra-thin alumina mask

Austenitic stainless steel patterning by plasma assisted

diffusion treatments

Integrated 3D gold nanoboxes

t = 3 s t =10 s

Deposition of SiOx by atmospheric pressure CVD with localized remote plasma

Introduction: Why creating surface pattern?

Lotus effect

Shark skin effect

Bio-inspired structured surfaces

S.J. Abbott, P.H. Gaskell, Proc. IMechE, Part C, J. Mechanical Engineering Science, 221 (2007) 1181

Gecko (Tarentola mauritanica)Corse, France

T. Czerwiec, “Patterning of metals for surface engineering: from top-down towards self assembly”, conference presented at the 61th workshop of the international union for vacuum science, technique and applications (IUVTA)

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Bio-inspired structured surfaces:

Lotus effect, Gecko, Cicada wings…

Self-cleaning and antireflective surfaces

NanodotsMagnetic data storage

Drag reduction in air and water : Shark skin effect…aeronautics, microfluidics…

Tribology (Lubrication…)Piston ring in automotive…

Introduction: Why creating surface pattern?

h

s

Wh

Wp

h : height of the patterned layer, s : period of the patterned layer

Wp: length of the protrusion, Wh: length of the cavity

Aspect ratio h/s

Application of patterned surfaces to drag reduction

D.W. Bechert, M. Bruse, W. Hage, R. Meyer, Naturwissenschaften, 87 (2000) 157P.R.Viswanath, Progress in Aerospace Sciences, 38 (2002) 571

0

Shear stress with (t) and without (t0) riblets

Drag reduction

tu

ssS+ dimensionless riblet spacing

NASA Langley Research Centre (USA)

ONERA/CERT (France)

Wind tunnel experiments

with 3M riblets on a 1:11 scale of an Airbus

A-320

Use of riblets

Fly tests (Mach

number 0.77-0.79)

on an Airbus A-

320 aircraft

Drag reduction in the range 5 -8% for bladelike ribs

with h/s ≥ 0.6100 ≤ h ≤ 200

mm

Application of patterned surfaces to magnetic data storage

A.O. Adeyeye, N. Singh, J. Phys. D, 41 (2008) 153001R. Luttge, J. Phys. D, 42 (2009) 123001E.A. Dobisz, Z.Z. Bandic, T.W. Wu, T. Albrecht, Proc. IEEE, 96 (2008) 1836

Hard disk drive

Overview of granular versus the patterned media for data storage

Superparamagnetic effect limits the size of a bit

h = 20 nm

s = 350 nm

Co dots

Boundary lubrication(sever wear)

Elastohydrodynamic or mixed lubrication

(moderate wear)

Full-film lubrication(negligible wear)

: m

fric

tion

coe

ffic

ien

t

h.v/P: viscosity. speed/pressure

Application of patterned surfaces to tribology (lubrication)

Stribeck curve

A. Kovalchenko, O. Ajayia, A. Erdemir, G. Fenske, I. Etsion, Tribology International, 38 (2005) 219.

Higher lubricant film thickness

h = 5.5 mm

s =200 mm

Comparison between flat surfaces and textured surface produced by laser surface texturing

Pin-on-disk friction test (steel ball, load 0.16 to 1.6 Pa, speed 0.015 to

0.75 ms-1)

Dimplesdensity

12%

Application in sliding guideways of machine toolsSliding contact elements

Magnetic storage disc surfacesMechanical face seals

Patterned surfaces leads to an improvement in load capacity, wear resistance, friction coefficient etc.. They can act as oil reservoirs and entrap wear particles (in either lubricated or dry sliding)They aid in the film formation of lubricant oilThey act as micro-reservoir for lubricant in case of starved lubrication conditions.

http://www.appropedia.org/Laser_surface_texturing#cite_note-nine-8I. Etsion, E. Sher, Tribology International, 42 (2009) 542

h = 9-10 mm

s =100-110 mm

Application of patterned surfaces to tribology (lubrication)

Better with dimples with low area coverage (10 to 15%) and h/s < 0.02 to 0.03 for s around 100 mm

Surface patterning can be combined with deposition of lubricant layers

(MoS2, DLC…)

Application to piston ring in automotive

Dynamometer tests on a compression engine have shown 4% lower fuel consumption for textured piston rings

http://www.appropedia.org/Laser_surface_texturing

Strategies for creating surface patterns:top-down, bottom-up, self-assembly

With or without mask (template) ? Serial or parallel?

Strategies for creating surface patterns

Bruzzone A.A.G., Costa H.L., Lonardo P.M., Lucca D.A., CIRP Annals. Manufacturing Technology 57 (2008) 750

Adding material: the patterned surfaces are created by addition of material to the desired surface, creating small areas of relief.

Removing material: the patterned surfaces are produced by removal of material of the surface, creating small depressions.

Moving material: the change in the surface structure is attributable to elastic or plastic deformation and redistribution of material from some parts of the surface to others.

Self-forming: a disordered system of components, already on the surface or brought to the surface, forms an organized pattern as a consequence of specific, local interactions among the components themselves.

Metalpatterning

K.P. Rajurkar, G. Levy, A. Malshe, M.M. Sundaram, J. McGeough, X. Hu, R. Resnick, A. DeSilva, Annals of the CIRP, 55 (2006) 643

Elaboration techniques: photolithography as a standard top-down approach

Mask with the pattern to be transferred

S. Roy, J. Phys. D, 40 (2005) R413M. Geissler, Y. Xia, Adv. Mater., 16 (2004) 1249R. Luttge, J. Phys. D, 42 (2009) 123001

Substrate covered by a photosensitive material resist

Gold deposition through a

polymeric mask

Etched Si with a gold layer as a mask

Resolution below 500 nm and around 45 to 25 nm for DUV and EUV lithography

Writing with a rigid stylus

(micromachining, STM, AFM…

Writing with a beam (photons, electrons, ions)

Writing with an electric field, or a magnetic field

Mask generation


Electro-physical and electro-chemical processes

S.Roy, J. Phys. D, 40 (2005) R413K.P. Rajurkar, G. Levy, A. Malshe, M.M. Sundaram, J. McGeough, X. Hu, R. Resnick, A. DeSilva, Annals of the CIRP, 55 (2006) 643Chakravarty Reddy Alla Chaitanya, Kenichi Takahata, J. Micromech. Microeng., 18 (2008) 105009


Electro-physical process (dielectric liquid)Micro-electro-discharge machining

Electro-chemical process (conductive liquid: electrolyte)

Chemical reactions with electron transfer across an interfaceMn+ + n e- ↔ M0

Electrochemical printing (EcP) Mn+ + n e- → M0

Electrochemical dissolution or machining M0 →Mn+ + n e-

Classical ECM use masks for localize etching

Elaboration techniques: other processes


S.Roy, J. Phys. D, 40 (2005) R413R. Schuster, ChemPhysChem, 8(2007) 34.K.P. Rajurkar, G. Levy, A. Malshe, M.M. Sundaram, J. McGeough, X. Hu, R. Resnick, A. DeSilva, Annals of the CIRP, 55 (2006) 643L. Cagnon, V. Kirchner , M. Kock, R. Schuster1, G. Ertl1, W. T. Gmelin, H. Kück, Z. Phys. Chem., 217 (2003) 299M. Geissler, Y. Xia, Adv. Mater., 16 (2004) 1249

Electrochemical micro-patterning with nano-second voltage pulses

Electrochemical nano-patterning by scanning tunneling microscope (STM)

Ni sheets patterned by W STM tips 0.2M electrolyte with 2 ns pulses

3M HCl/6M HF electrolyte with a 143 ns pulse

Laser induced chemical vapor deposition (LCVD) Focused beam (ions or electrons) CVD Inkjet printing Dip-pen nanolithography Electro-hydrodynamic atomization

Other add-on processes

Serial mask-less processes : localized PACVD

Advanced serial mask-less processes (self-assembly?)

Capillary ( 100 µm)

HV DC

450MHz ~

Metal tube

Gases

Cu w

ire

~

~3 mm

Y. Shimizu et al., Surf. Coat. Technol. 200 (2006) 4251A. Holländer and L. Abhinandan, Surf. Coat. Technol. 174-175 (2003) 1175

’Tower’ of hydrocarbon deposited by microjet CVD(10 s, 8 sccm acetylene, 0.25 mm capillary, 8.4 mm away from the substrate, 12 W rf) The peak is 2.4 mm high.

‘Tower’ of tungsten oxide deposited by wire spraying

Using self-assembly

The formation of these self-organized structures may be explained by the presence of

strong electromagnetic EM fields at the processing surface.

A. Holländer and L. Abhinandan, Surf. Coat. Technol. 174-175 (2003) 1175D. Mariotti, V. Svrcek, D.G. Kim, Appl. Phys. Lett., 91 (2007) 18311.





Atmospheric pressure CVD by localized remote plasma

Microwave power supply Circulator

Mass flowcontroller

Coaxial cable

O2Ar

Rotating fan

Substrate (SS)

Plasma

Fused silica tube

Microwave cavity

Teflon ® rung

Ar/HMDSO inlet

Ar

HMDSO

Thermostat bath

Microwave power supply Circulator

Mass flowcontroller

Coaxial cable

O2Ar

Rotating fan

Substrate (SS)

Plasma

Fused silica tube

Microwave cavity

Teflon ® rung

Ar/HMDSO inlet

Ar

HMDSO

Thermostat bathAr-10%O2 (275 sccm) Plasma Power: ~120 WHole diameter: 400 µm Ar-0.17% HMDSO (200+30 sccm)

HMDSO

inner wall of the cavityplasma

Ar-10%O2


19

« nest-like » structure hexagonal walls

nano-dots

pleated film

Between 0.5 et 5mm

From 200 nm to 6 µm

SiOx



Atmospheric pressure CVD by localized remote plasma


Additive parallel processesWith masks (templates)

H. Masuda, K. Fukuda, Science, 268 (1995) 1466 and H. Masuda, M. Satoh, Jpn J. Appl. Phys., 35 (1996), L126 Yong Lei, Weiping Cai, Gerhard Wilde, Progress in Materials Science, 52 (2007) 465

Additive processes : nano-patterning using ultra-thin alumina masks (UTAM)

Electrochemical method combined with nano-patterning techniques

Highly ordered porous aluminum oxide layers can be formed in optimized acid electrolytes

Pore diameter (10-200 nm) and cell size (25-420 nm) with an hexagonal arrangement

Membranes formed in these nano-porous anodic aluminum oxide can be used as templates

Fabrication process of attached UTAMs Fabrication process of connected UTAMs

Advanced parallel processes with mask (directed self-assembly)

Additive processes : building blocks

Advanced parallel processes with mask (self-assembly)

J.Y. Cheng, C.A. Ross, H. I. Smith, E.L. Thomas, Adv. Mater. 18 (2005) 2505T.W. Haley, Nanotechnology, 14 (2003) R39Hidetaka Asoh, Seiji Sakamoto, Sachiko Ono, J. Colloid Interface Science, 316 (2007) 547

Different types of building blocksBlock copolymers

Nanolithography for Co dots array fabrication

Colloidal or nanosphere particles

Honeycomb and isolated-island Cu

patterns.

Cu patterns with 500 nm interval (electroless plating in CuSO4/HF)

Removal serial and parallel processes :

energy beams

Energy beam processes : laser direct imaging

Metal drilling process

S. Roy, J. Phys. D, 40 (2005) R413P. G. Engleman, A. Kurella, A. Samant, C. A. Blue, N. B. Dahotre, JOM (2005) 46I. Etsion, E. Sher, Tribology International, 42 (2009) 542

Multi-scaled zirconia (ZrO2) coating on a

Ti-6Al-4V alloy substrate. ZrO2

powder was mixed with a water-based organic solvent and

was sprayed onto Ti-6Al-4V substrates and

fused with a pulsed Nd:YAG laser

operated at 10 kHz and at a constant power of 25 W.

Metal writing process

Piston ring (steel) texturation by direct laser imaging

Removal serial mask-less processes

Energy beam processes : laser shock peening

120 mm

0,5 mm

Y.B. Guo, R. Caslaru, Fabrication and characterization of micro dent arrays produced by laser shock peening on titanium Ti–6Al–4V surfaces , Journal of Materials Processing Technology 211 (2011) 729–736

Removal serial mask-less processes

Creation of micro dent (dimples) arrays on a titanium alloy by laser

shock peening

Energy beam processes : laser sub-surface patterning (3D)

Z. L. Li, T. Liu, C. C. Khin, A. C. Tan, L. E. Khoong, H. Y. Zheng, W. Zhou, Direct patterning in sub-surface of stainless steel using laser pulses, OPTICS EXPRESS 18 (2010) 15990.

Removal and moving serial mask-less processes

Nd:YAG laser pulse, peak power density of 1 MW/cm2

Potential applications : security marking, micro-devices based on porous materials : micro-heater, micro-insulator and micro-sensor.

Stainless steel

substrate

Energy beam processes : laser interference metallurgy

M. D’Alessandria, A. Lassagni, F. Mücklich, Applied Surface Science, 255 (2008) 3210M. Duarte, A. Lassagni, R. Giovanelli, J.Narciso, E. Louis, F. Mücklich,, Advanced Engineering Materials, 10 (2008) 554

Laser interferences are obtained from the interaction of two or

three laser beams

The interference pattern covers the size corresponding to the

beam diameter

The obtained textured surfaces are the negative of the

interference pattern (molten of metal at the interference

maxima)

No mask and no etching

mdi

105

)2/sin(2

Removal and moving parallel mask-less processes

http://archiv.uni-saarland.de/de/

Removal and moving parallel mask-less processes

Line-like periodic patternTwo laser beams

Dot-like periodic patternThree laser beams

Cross-like structures, two laser beams → line-like structuresSample rotation 90°, two laser beams → cross-like structures

Energy beam processes : laser interference metallurgy

M. D’Alessandria, A. Lassagni, F. Mücklich, Applied Surface Science, 255 (2008) 3210M. Duarte, A. Lassagni, R. Giovanelli, J.Narciso, E. Louis, F. Mücklich,, Advanced Engineering Materials, 10 (2008) 554

http://archiv.uni-saarland.de/de/

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2+

Ar +

or

Rapid neutrals

N

Removal parallel mask-less processes

Energy beam processes : Ion beam

High ion energy (1 keV) Sputtering

Negative transfer to the substrate

« Patterning of magnetic structures on austenitic stainless steel by local ion beam nitriding »

SEM

MFM

Magneto-optic Kerr effect (MOKE) magnetometry

E. Menendez, A. Martinavicius, M.O. Liedke, G. Abrasonis, J. Fassbender, J. Sommerlatte, K. Nielsch, S. Surinach, M.D. Baro, J. Nogue´s, J. Sort, Acta Materialia 56 (2008) 4570.

Moving parallel processes : Patterning by nitriding

Towardstress patterning

engineering


Surface Patterning by plasma assisted nitriding at low ion energy

Stress and anisotropic strain

Substrate

Nitrided layer (without stress and nitrogen)

Substrate

s

Internal stress necessary to return film

to substrate dimension

Nitrided layer (with nitrogen)virtually removed from the substrate

Substrate action on the layer

Nitrided layer (with nitrogen)virtually removed from the substrate Dx

e

Dilatational or compositional strain (ec)

Elastic strain (ee) Internal stress (s)

T. Czerwiec, G. Marcos, T. Thiriet, Y. Guo, T. Belmonte, to be published in IOP Conference Series: Materials Science and Engineering

Fcc lattice

Dilatational or compositional strain (ec)

Nitrogen introduction

Moving parallel processes with mask

N N

Initial interface

Without maskWith a mask

Elastic and/or plastic deformation induced by nitrogen incorporation

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0.75

50 mm

50 mm

Surface Patterning by plasma assisted nitriding at low ion energy

Moving parallel processes with mask

Principle of surface patterning by plasma assisted nitriding

Initial interface(AISI 316L)

With a mask

N

Remote plasma assisted nitriding

N

N N

N N

N N

N

Gas inlet

Primary and turbomolecular pump

450 mm

360 mm

Antenna

Gauge

Substrateholder

microwave power supply

Elastic and or plastic deformation induced by nitrogen incorporation

Micropatterning!

Grid: mesh side of 200 * 200 µm2

Copper TEM Grids

Exemple of surface patterning by plasma assisted nitriding

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3 mm

3 mm

Plasma: 60% N2 + 40% H2

Substrate temperature: ~ 400 °C

Pressure: 5.75 Pa

Process duration: 1h

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0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 µm

High step mean : ~240 nm

High step mean : ~275 nm

Extraction of profiles :Surface profilometry

46 48 50 52 54 56 58 60 62 64

4000

6000

8000

10000

12000

2

Inte

nsity

[A.U

.]

Grids No grids

4000

8000

12000

16000

20000

X-ray diffraction patterns

10 µm

Cross section of a step

Cross section of one dot

30 µm

2 µ

m

Silicon oxide layer patterned: procedure (coll LPN)

AISI 316L

Polished like-mirror

PECVD

N2O/SiH4

Spin coating

AZ5214 photoresist

UV photolithography

CCP RIE

SF6 /CHF3

CCP RIE

O2

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500 nm

Patterned mask: features and characteristics

SEM picture

Cylindrical dots with diameters from 3 to 15 µm

AFM picture (height mode)

Patterned mask and expanded austenite

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Longueur = 50.0 µm Pt = 0.843 µm Echelle = 1.00 µm

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Longueur = 50.0 µm Pt = 0.983 µm Echelle = 1.00 µm

Dots after nitriding in MDECR: 4 h. at 400 °C (80% N2 – 20 H2), bias 0 V

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500 nm 550 nm

500 nm500 nm

In such conditions, the nitrided layer is 5.6 to 6 µm thick and we are waiting for a 500 nm to 600 nm expansion (same height for SiO2 dots

and substrate)

What happens?



Dot with a diameter of 7 µm

No strongly distortion

Dot with a diameter of 15 µm

A toroidal-shell shape!



0 10 20 30 40 50 60 70 80 90 100 110-500-400-300-200-100

0100200300400500600700800900

1000

DotsNitrided parts Nitrided parts

500 nm

300 nmto

900 nm

200 nmto

750 nm

Expansion of the nitrided layer (as expected)

Vertical movement of the SiO2 dots (totally for the smaller ones; at edges for the bigger)

What is the role of expanded austenite ?


SEM cross-sections after 2 nitriding processes in MDECR: 4 h. at 400 °C (80% N2 – 20 H2),

bias 0 V

Expanded austenite

Austenite

Dot

For the small dots: nitrogen completely diffuses under the mask For the big dots: only a diffusion under mask edges

Progressive mask distortion

Dots with 800 nm of thick. Same shapes.

0,0 2,0x104 4,0x104 6,0x104 8,0x104 1,0x105

-800

-600

-400

-200

0

200

400

600

800

1000

1200

1400 4h 6h 8h 10h

nm

nm

Different nitriding steps at 400 °C (80% N2 – 20 H2)

Progressive mask distortion

After 10h nitriding

4h

6h

10h

CONCLUSION

Surface patterning was introduced

Some applications of surface patterning (drag reduction, lubrication, self-cleaning

and magnetic data storage) were presented to show the importance of shape and

aspect ratio in surface patterning

Based on an tentative classification of strategies for surface patterning, different

elaboration techniques were presented (photolithography, advanced serial mask-less

processes, advanced parallel processes with masks, advanced parallel mask-less

processes

Finally, a strain driven patterning method developed by us was presented: austenitic

stainless steel patterning by plasma assisted diffusion treatments:

ACKNOWLEDGMENTS

IJL “ESPRIT” team