Nanolitografías basadas en el uso del microscopio de fuerzas

Nanolitografías basadas en el uso del microscopio de fuerzas

ForceTool
Nanolitografías basadas en el uso del
microscopio de fuerzas
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Scanning Probe Lithographies
Scheme
●Introduction AFM (10 minutes)
●Overview Scanning Probe Lithographies (SPL) (40 m.)
●Applications (20 m)
●Summary (5 minutes)
Direct
Write
●Questions
(15 m.)
R. Garcia, Instituto de Ciencia de Materiales de Madrid
ForceTool
Top-down and Bottom-up approaches in Nanotlithography
Top-down y Bottom-up en Arte
Miguel Angel
Bunarroti,
David (1504)
Georges Seurat,
La Parade (1889)
R. Garcia, Instituto de Ciencia de Materiales de Madrid
ForceTool
Dynamic Atomic Force Microscopy
i). Introducción
Invention of Scanning Probe Methods
ii). Forces and Dynamics
iii). Basics of AFM
RicardoGarcía
García
Ricardo
Instituto de Microelectrónica de Madrid
Instituto de Ciencia de Materiales de Madrid
ForceTool
STM (scanning tunneling microscope); Binnig and Rohrer (1982). Electron
current
AFM (atomic froce microscope). Molecular and Adhesion forces
SNOM (scanning near field optical microscope). Intensity of light
SPM (scanning probe microscope);
SXM: Kelvin Probe Microscope, Magnetic Force Microscope, Friction Force Microscope...
Instituto de Microelectrónica de Madrid
Ricardo Garcia, Instituto de Ciencia de Materiales de Madrid
ForceTool
human environment
universe
27
10
18
9
10
10
km
mm
protons
atoms
-15
10
nm
Classical Physics:
-21
10
Quantum Physics
Nanoscale
Systems
are composed by a finite number of atoms:
statistical averages may not work
Quantum
effects
Discretization of electronic energy leves
Co-existence of classical and quantum phenomena
Instituto de Ciencia de Materiales de Madrid
ForceTool
G. Binnig : Is it necessary to have either
particles or waves to make a microscope
?.
AFM, Binnig, Gerber, Quate Phys. Rev.
Lett. 56, 930 (1986)
Result: AFM
Concept: touch: Forces
Ricardo Garcia, Instituto de Ciencia de Materiales de Madrid
ForceTool
0,10
0,05
0,00
-0,05
Molecular motors, H Seelertet, A.
Engel, D.J. Muller (2000)
2 m
Cells, R. Acvi (2007)
Polymers, R. Magerle (2004)
Nanopatterning, G. Binnig
(1999)
-0,10
0
10
20
30
40
50
60
Force spectroscopy
Atom identification,
O. Custance, S.
Morita et al. (2007)
15 nm
Antibodies, A.S. Paulo, R. Garcia
(2000)
70
devices
Nanomechanical sensors
J. Tamayo (2007)
Probe lithography
R. Garcia, Instituto de Ciencia de Materiales de Madrid
80
90
100
26 years after the invention of force microscopy
Forces below 10‐18 N still to be reached
Lateral resolution 3 nm improved to 0.1 nm
Vertical resolution 0.1 nm improved to 10 pm
Top 10 Advances in Materials Science since 1950
1.
2.
3.
4.
5.
J. Wood, Materials Today 2008
International Road Map Semiconductor
Scanning Probe Microscopy
Giant magnetoresistance effect
Semiconductor lasers/diodes
National Nanotechnology Initiative (USA)
Wood, J. The top ten advances in materials science. Mater. Today 11, 40 (2008).
Ball, P. Material witness: Greatest hits. Nature Mater. 7, 102 (2008).
ForceTool
AM‐AFM
Fixed excitation frequency
constant oscillation amplitude
Cantilever
Piezo oscillator
Electronics and feedback: constant amplitude
Tip
Sample
Scanner
Piezo XYZ
Computer and display
Instituto de Microelectrónica de Madrid
5 m
ForceTool
Instituto de Microelectrónica de Madrid
ForceTool
Forces:
Short and Long range
Conservative and dissipative
Dynamic AFM:
amplitude, frequency, phase shift
15
(1988-2007)
repulsive
F (nN)
10
5
0
attractive
-5
-0.5
0.0
0.5
1.0
d (nm)
Contact : static deflection,
F=kz
Binnig, Quate, Gerber (1986)
dissipation
R. Garcia, Instituto de Ciencia de Materiales de Madrid
1.5
2.0
A force acting on a vibrating cantilever changes its
resonant frequence and reduces its amplitude
amplitude, frequency, phase shift
Amplitude (nm)
Dynamic AFM:
1.5
1.0
0.5
amplitude
(1988-2007)
attractive repulsive
non linear
2.0
dynamics
0.96
0.98
1.00
1.02
1.04
frequency ratio
frequency
Two main dynamic AFM modes
Frequency Modulation AFM feedback on the frequency
T.R. Albrecht, P. Grütter, D. Rugar, JAP 69, 668 (1991)
Amplitude Modulation AFM feedback on the amplitude
Martin, Williams, Wickramasinghe JAP 61, 4723 (1987)
12
ForceTool
El sistema de detección óptico mide cambios de pendiente
2 L dz ( L)
z ( L) 
3 dx
z
x
R. García, Instituto de Microelectrónica de Madrid
ForceTool
Microcantilevers
Mechanical device to detect and amplify tip‐
surface interactions
Si or Si3N4
The dynamic response of the cantilever is characterized by three quantities: force constant kn , resonance frequency fn and quality factor Qn
50 m
10
3 EI
Ebt 3
k 

3
L
4 L3
Q0/2

Power
8
6

4
10 m
2
1
fn 
2
k
C n2 t

mn 2 L2
E
0
0.2

0.4
0.6
0.8
1.0
1.2
1.4
1.6
f/f0
Resonace
frequency
Force constant
Q-factor
104-4x 105 Hz
0.01-50 N/m
1-105
R. García, Instituto de Microelectrónica de Madrid
5 m
ForceTool
Forces in AFM
Restoring force cantilever
Fc=‐kz
Force (nN)
40
0
PM
‐40
van der Waals forces
ts
‐80
0
2
4
6
8
Fvdw 
10
Separation (nm)
HR
6d 2
Excitation force
F0cos t
Capillary forces
Hidrodynamic forces
Adhesion forces
Fa=4R
m  0 dz
Fh 
Q dt
Short range repulsive forces (DMT)
FDMT  E * R 3 / 2
Instituto de Microelectrónica de Madrid
R.
García, Instituto de Microelectrónica de Madrid
ForceTool
Amplitude modulation AFM (tapping mode AFM):
an image is formed by scanning the tip across the surface at a fixed oscillation amplitude. Zhong et al. Surf. Sci. 290, L688 (1993); Anselmetti et al. Nanotechnology 5, 87 (1994); García, Pérez, Surf. Sci. Rep. 47, 197 (2002).
Instituto de Microelectrónica de Madrid
ForceTool
collaboration with Wojciech Kaminski, Rubén Pérez, UAM
Silica tip on oligothiphene monolayer
short: 5 Å  2 Å  5 Å
middle: 5 Å  0 Å  5 Å
Wojciech
Kaminski,
Rubén Pérez de Madrid
Instituto
de Microelectrónica
•
C position
long: 5 Å  -1 Å  5 Å