Surface Engineering Nanostructures - FAPESP · Surface Engineering Nanostructures 1) Sculpted...
Transcript of Surface Engineering Nanostructures - FAPESP · Surface Engineering Nanostructures 1) Sculpted...
Surface Engineering Nanostructures
Low energy Ion bombardment nanostructuring Process
Fernando Alvarez
Instituto de Física "Gleb Wataghin", Unicamp, 13083-970, Campinas, SP, Brazil
- Photo-lithography: Expensive, 100nm
- Scanning Beam Lithography: Low deposition rate, 10 nm
- Scanning Probe Lithography: Low deposition rate, 1 nm
Top Down: “Imposing” a pattern on the Substrate
Surface Engineering Nanostructures
1) Sculpted Substrate By Ion Beam Bombarding
2) Ni Self–organized Structures Obtained on the sculpted substrate
Ion BombardingTop–Down and Bottom-Up hybrid
- Resolution: 1nm
- One step process
- Large Areas
Bottom Up: Guiding the assembly of atoms or molecules
Bottom Up Fabrication: Mesoporous Patterned Silica (Sol Gel Technique)
J.J.S. Acuña, M.C. Marchi, F. Alvarez, Thin Solid Films 519 (2010) 214–217
• Silica Based Thin Film: cubic symmetry (polycondensation + evaporation+ self-organization )
• 7 nm cavities sizes separated by ~1.8 nm walls
• CVD Carbon Nanotubes Growth catalyzed by Ni
TEM-Cross Section SEM-Top View
Black dots: Ni catalytic decorated substrate
SEM-Top View
(b)
1W. K. Burton, N. Cabrera and F. C. Frank, Royal Soc., 243, 1950; D. Walton in Nucleation, Edited by A. Z. Zettlemoyer, Marcel Dekker, INC. NY, 1969; W. K. Burton , N.
Cabrera. And F. C, Frank, Phil. Trans. Roy Soc., London, A243, 302, 1951
Surface Process: a brief introduction
• Atoms arrive from the vapor phase
• Self-Organizing: Mean Way between kinetic and thermodynamic phenomenon
• Surface diffusion on a flat surface (terrace): primary mechanism (activated process)
• Mean displacement adatom : distance before remains immobilized or detaching to the vapor1
=0exp [ (s-us)/2kT]
s : evaporation energies
us : activation energy
Jumping
Detaching
F
• D/F>>1 Process Governed by Thermodynamic
(Near Equilibrium)
• D/F<<1 Process Governed by Kinetic
D= Diffusion Coefficient, F= Particles Flux
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Surfaces nano-structuration
Navez, et al., C.R. Acad. Sci., 254 (1962)
First Experiments by Ion Bombarding
Valbusa et al., J of Phys: Cond. Mat. 14 (2002)
Glass, Ionized air, 6 hs, 4 kV
30°
0°
80°
5000 Å
5000 Å
5000 Å
Canhão
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Campinas Sky, SP, Brazil
Snow Ripples Las Leñas, Argentina
Atacama Desert, Chile
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Topography Accident: Sand and Snow
Sand(Snow) Dunes: At the hill or depression, Different Velocities
Clouds: ripples between the dry, cool air above and the moist, warm air
below
Small Velocity
WindHigh Velocity
Low energy Ion bombardment nano-structuring Process
Control Deposition Parameters
• Ion Species
• Ion Energy
• Impinging Angle
• Flux (Dose)
• Substrate Temperature
Noble gases Bombardment (NG +): Ar +, Kr, + Xe +
Experimental: Ion Beam
Energy
20 – 1200 eV
PO2 <10-8 mb
Current
~1mA/cm2
TARGET
SUBSTRATE
T Controlled
ION GUN 2
TURBO
PUMP
NG+
ION GUN 1
Ion gun
(Kaufman)
Ar, Xe+
In Situ
Photoelectron
Emission
Spectroscopy
TURBO
PUMP
SEM-FEG images: AISI 316L (Room T, Xe+, 1 keV)
•10Cucatti, Alvarez., ,submitted, 2014
Crystalline grains
evidenced
Patterns within the
crystalline grains
15º
Pattern
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Nano-Structures on Semiconductors
500nm
GaSb, Gallium Antimonide
Facsko et al., Science 285,1999, p1551
Hexagonal Symmetry
Ar+, 2 KeV, perpendicular
Xe+, Si (110), 1keV, 15°Morales, Merlo, Droppa, and Alvarez, 2014, J. of. Phys: D
<0
01
>
<001>
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Semiconductors Nano-structuration
Substrate: Si, Ar+, Room TemperatureIon energy dependence
Ziberi et al., J. Phys: Condens. Mat. 21 (2009)
800 eV 1200 eV 2000 eV
An
gu
loi:
15°
An
gu
loi:
20° 800 eV1200 eV 500 eV
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Ion patterning: Bradley & Harper Model
ConvexConcave
M. Bradley and J. M. E. Harper, J. Vac. Sci. Technol. A, 6,4, 1988Faster Erosion
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TiN + Ni Particles Ion Beam Deposition
Sputtering
gun
Turbo
pump
XPS
Carbon nanotubes grown by CVD, M. Morales,et al., JPhysD., 2013, 2013
Si
Nickel Particles
750°C
1.5 min deposition
5 min annealing
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TARGET UHV
XPS
SUBSTRATE
T Controlled
ION GUN 2
TURBO
PUMP
NG+
ION GUN 1
Ion gun
(Kaufman)
Ar, Xe+
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Ni Atoms Flux
Morales, Merlo, Droppa, Alvarez, J. of. Phys: D, 2014014)
Ion Gun
Vacuum
XPS
Annealing
750°C, 1.5 min , deposition
5 min annealing
Ni Deposition + Annealing
Fourier Transform
Atomic Force Microscopy
16Morales, Merlo, Droppa, and Alvarez, 2014, J. of. Phys: D
Conclusions
• Different possibilities generating regular nanostructures by ion
bombarding
• Self-organized metallic nano-particles on sculpted patterned silicon
• Self-organization: Irregularities & defects still important
• Lack of general theoretical understanding
about the general patterning
and self-organization process
Nitriding
Put a three years old black goat in a locked room, without food;
after the four day, feed the animal only with fern during two
days. The following night, put the goat in a vat with holes in the
button to collect the urine's goat. Store the urine of two or
three nights and throw out the goat. Therefore, temper yours
instruments in the collected urine.
Iron instruments are also very well tempered in the urine of a
young red haired boy, giving more hardening that tempering
simply in water.
Theophilus Presbyter (Roger of Helmarshhausen, Germany)
(Monge Beneditino, 12th Century),Scheme of Various arts,
translated to English from Hendrich, 1847.
Equipamentos e ProcessosEquipamentos e Processos
Instituto de Física “Gleb Wataghin”UNICAMP, SP, Brazil
Supporting Agency: FAPESP
Daniel Wisnivesky
Fernando Alvarez
Plasma-LIITS
Surfaces Plasma Processing
Gear Box Manufacturing
2004
Industrial
ApplicationsPlasma Nitriding
Industry
Small Company
Equipment and Processes
Equipamentos e ProcessosEquipamentos e Processos
• Metallic Surfaces treatments by plasma: R & D
• Equipment for nitriding and coatings: R & D
• Alternative to Salt Bath and Ammonia
• Interaction with the industry
PRIMARY COMPANY GOALS
Equipamentos e ProcessosEquipamentos e Processos
COMPANY EVOLUTION
PRODUCTS IN 2014
• Nitriding Equipments
• Pulsed Power Supply
• Hard Coating Equipments
• R&D: Processes and Equipments
• Industrial Consulting
• HiPIMS Equipments (High Power Impulse
Magnetron Sputtering)
Nitriding Plant Fully Automatic
Vacuum
Furnace Pulsed
Power Supply
CLP
Heater Control
Automatic Gas Console
Roll - to - Roll Thin Film Deposition
Solar Absorber Panels
Plasma Immersion (PI3) Nitriding System (25 keV)
+
Remote Auxiliary RF Plasma
Cooling
System
RF Generator
Pulsed PI3 Power
Reactor
Molds for Plastic Injection+Oxidation(P20, P50, H13)
Equipamentos e ProcessosEquipamentos e Processos
High Speed Steel Cutting Tools( M2, M35, M42)
0 20 40 60 80 100 120
Horas de uso
Cortador "Caracol"
Horas de uso
Nitretada
Equipamentos e ProcessosEquipamentos e Processos
Cold Work( D2, D3, D6)
Thanks for your attention
谢谢
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Thanks for your attention
S. J. Liu et al. Appl. Phys. Lett., Vol. 80, No. 18, 6 May 2002
{111}{111}
Top View
Instability: Piling up along the terrace
Eb~ 0.45 eV
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Ehrlich-Shhwoebel (E-S) barrier
Self - Organization
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L
L0
L
L0
-s +s
Implanted layer (~5-10 Ǻ)
Bulk
Modified region (~1)
x-ray
penetration
depth
(~980nm)
Stress
0 100 200 300-550
-50
0
50
100
150
200
Initial compressive stress
Xe+
Kr+
Ar+
Str
ess (
MP
a)
Implantation Energy (eV)
Steel100Cr6(AISI 52100)
X-Ray diffractionSeeman-Bohlin
Replacement Collision Sequence (RCS)Newton Cradle (Momentum Conservation)
Shortcut to pendlots.lnk
Account for defects <10 nm depth*
Highly anharmonic localized excitations (such as a DB) which propagate
distances well beyond the ion penetration depth can explain deeper deffects+
* P. Hansen, Phys. Metal., 2003; + G. Abrasonis & W. Moeller, PRL,2006
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1 m
1 Kv, X 25000
1.5 µm
1 Kv, X 25000
1 m
0.9 µm
SS316; T=390 0C, 4 hs
20 eV, Xe+ pre-bombardedSS316; T=390 0C, 4 hs
Without pre-bombardment
Nitrided Case : SS 316
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38 40 42 44 46 48
N(200)
(111)
N(111)
No Bombarded Nitrided 4 hs
Inte
nsid
ade
, u.a
.
2, Grauss
50 eV Xe+ Bombarded & Nitrided 4 hs
300 eV Xe+ Bombarded & Nitrided 4 hs
Grazing X-Ray Diffractograms
Pre-Bombarded and Nitrided SS316
X-Ray Penetration depth ~0.15-0.20 m
= 1.5 4056 Å
Bragg-Brentano
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35 40 45 50
0.0
0.5
1.0
T= 400 0C, 30
2(degree)
Inte
nsity (
arb
.units)
Xe++ Nitrided
Kr++ Nitrided
Ar++ Nitrided
Only Nitrided
+'(
´
=20 grazing angle
Grazing X-Ray Diffractograms
Pre-Bombarded and Nitrided AISI 4140
X-Ray Penetration depth ~0.15-0.20 µm
3 KV, Xe+
= 1,54056 Å
Bragg-Brentano
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Difussion Coefficient
Polycrystalline multiphase system , `,
From the Phase diagram Fe-N: C´s
Diffusion
coefficient
I=Without
Pre-
treatment
II=With Pre-
treatment
Ratio
II/I
Dε (µm2/s) 0.88x10-4 3.7x10-44.6
D´ (µm2/s) 3.4x10-4 6.9x10-4
2
D (µm2/s) 0.32 0.32 1
Faster diffusion
Grain border, dislocations
Lower packing density
“Irrigation channel”
Adapted from
P. Hansen, Phys. Metal., 2003
Nitrogen Concentration
0 500 1000 1500
10
20
30
0 5 10 15 20 25 30
4
6
8
10
12
14
Ha
rdn
ess,
GP
a
Nitrogen content, at. %
Only nitriding (0.5 hr)
Xe+ pre-treatment (125 eV)
+ nitriding (0.5 hr)
Nitro
ge
n c
on
ten
t, a
t. %
Depth, nm
Sputtered Neutral Mass Spectroscopy
AISI 4140, 400 0C
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Conclusions
•Implantation (knock-on) Xe+, Kr+, Ar+: stress
•Atomic Attrition: nanoscopic scale grain refining
Thanks for
your
attention
•Increasing Nitrogen Retention at Surface
•Improving Nitrogen Diffusion: thicker case
•Decreasing process time
•Thermal spike: relaxation
•Sequential Collision Effect
•Deeper changes due to other effects: e.g.: DB
•Increasing effective diffusion coefficient
•(–
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ESTUDO DA NANOESTRUTURAÇÃO DE
SUBSTRATOS CRISTALINOS ATRAVÉS DO
BOMBARDEAMENTO COM FEIXE DE ÍONS A
BAIXA ENERGIA
Mónica Morales Corredor
Orientador: Prof. Dr. Fernando Alvarez
Exame de Qualificação de Doutorado
Campinas, abril de 201476
Sumário
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Motivação
Métodos
Exemplos de Nano-estruturação de superfícies
Modelo do Bombardeamento com feixe de Íons
Experimento
Perspectivas
77
Sumário
78
Motivação
Métodos
Exemplos de Nano-estruturação de superfícies
Modelo do Bombardeamento com feixe de Íons
Experimento
Perspectivas
78
Parâmetros envolvidos
Temperatura
Substrato
Ângulo de
bombardeamento
Tipo de íons
Energia de
bombardeamento
Fluência
Interação de átomos
energéticos com a
superfície
Sputtering
79
Nano-estruturação de superfícies- BFI
Diversidade de nanoestruturas
formadas79
Nano-estruturação de Metais
Temperature Dependence
80
Ag (110), Ângulo: 0° t:15 min Gás: Ar Eí: 1 keV
160 K 230 K 270 K
290 K 320 K350 K
Rusponi S, et al. Phys. Rev. Lett. 78 (1997)
80
Nano - structuration of metals
81
Valbusa, J. of. Phys: Cond. Mat. 14,
(2003)
Substrates
180 K, 70°, 10 min, Ar+ , 1 keV
Ag(001) Cu(110) Ag(110)
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Nano - structuration of metals
Bombarding Angle
Cucatti S, Alvarez F Mat. Chem. Phys (2014), Submitted
Policrystal
φ =15º φ = 45º
φ = 60º
0 15 30 45 600
5
10
15
20
25
Ru
go
sid
ad
e R
MS
(n
m)
ângulo de incidência (graus)
Amostra polida (<1.5 nm)
SS316L: Room Temperature, 15°, 30min, Xe+, 1keV
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Nano-estruturação de
semicondutores
Fluência
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Si
Ge
Cornejo, dissertation (2011)
Substrato: Si Gas: Kr
Ei: 2 keV Angulo
=3.4x1017íons cm-2 =1.1x1018íons cm-2
=6.7x1018íons cm-2 =1.3x1019íons cm-2
AFM
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Sumário
84
Motivação
Métodos
Exemplos de Nano-estruturação em superfícies
Modelo do Bombardeamento com feixe de Íons
Experimento
Perspectivas
84
Bombardeamento com feixe de íons
85
Íon
incidente
migrante
sputtering
Implantação
fase
Amorfa
~2 nm
Sputtering (curvatura
Mecanismos de difusão
85
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Bombardeamento com feixe de íons
Sputtering Yield
Emm
mm
UY
ti
ti
2
0
2 )(
4
4
3
+
s(E)- stopping power~1 keV
i
t
m
moU Surface binding energy
Teoria de Sigmund Phys. Ver, 184 (1969)
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Bombardeamento com feixe de íons
Sputtering Yield
87
Bombardeamento com feixe de íons
Sputtering Yield
8888
Bombardeamento com feixe de íons
89
Modelo de Bradley and Harper – 2D
Rx > 0Rx < 0 Erosão mais rápidajDistribuição esférica
Rx
>> a
j=0 incidência
normala- Alcance médio de penetração dos
íons
J- Fluxo de íons incidentes
n-Densidade de átomos do substrato89
Modelo de Bradley & Harper- 3D
Bombardeamento com feixe de íons
90
Migração
dos
ripples
Difussão
superficial
adatomos
Taxa
erosão
superfície
plana
Sputtering
dependent
e da
cuvatura
Incidência não-normalz = h(x,y)
x
y
j
90
Longos tempos tem saturação e efeitos não lineares que não explica o modelo- Fluência.
Válido também para superfícies lisas.
Influência de impurezas
Outros modelos explicam os efeitos de ordem
maiores e não lineares.
91
Bombardeamento com feixe de íons
Falências do modelo B-H
91
Sumário
92
Motivação
Métodos
Exemplos de Nano-estruturação em superfícies
Modelo do Bombardeamento com feixe de Íons
Experimento
Perspectivas
92
Experimento
Motivação e Objetivo
AFM SEMSEM
Carpete de
nanotubos
alinhadosSubstrato nano-
estruturado
Barreira
Ilhas de níquel
9393
Experimento Resultados
94
Substrato: Si
Íons: Xe
Energia i: 500 eV
holes
Per. Ripp
SmoothHolesRipples Per.
Ziberi et al.
5° 10°
15° 20°
a b
c d<010>
<0
01
>
94
Experimento Rugosidade
95
5° 10°
15° 20°5 10 15 20
0,1
1
10
Ru
go
sid
ad
e R
MS
(n
m)
Ângulo de incidencia (°)
Si(100) polido
Xe+
Ziberi, 2009
0 10 20 30 40
0,1
1
10
Ru
go
sid
ad
e R
MS
(n
m)
Ângulo de incidencia (°)
Ar+
95
Experimento
9696
Sumário
97
Motivação
Métodos
Exemplos de Nano-estruturação em superfícies
Modelo do Bombardeamento com feixe de Íons
O experimento
Perspectivas
97
98
Fluxo de átomos de Ni Perspectivas
M Morales et al., J. of. Phys: D
(2014)
OBRIGADA!
99
Nano-Structures on Gallium Antimonide: Ar+ Ion Sputtering
Facsko et al., Science 285,1999, p1551
Hexagonal Symmetry
4x1017 cm-2, 40 s 2x1018 cm-2, 200 s 4x1018 cm-2, 200 s
500nm 500nm 500nm
GaSb
Fluences:5.2x1031/nm2;Tempo: 90 min and =37–43 nm
Au
~730Dual Ion Beam Sputtering, 2keV
101
Xe+ Patterning: Experiment
108
•Substrate
•Ion gun
•Turbo
•pump
Material: SS 316, Policrystal (austenite)
XPS
TiN + Ni Particles Ion Beam Deposition
Sputtering
gun
Turbo
pump
XPS
Carbon nanotubes grown by CVD, M. Morales,et al., JPhysD., Submitted, 2013
Si
Nickel Particles
750°C
1.5 min deposition
5 min annealing
132
136
Ni Atoms Flux
M Morales et al., J. of. Phys: D
(2014)
140
谢谢