Scanning Probe Microscopy
Nanoscience and Nanotechnology
Huixin He
Room 234, Olson Hall
Phone: 973-353-1254
Email: huixinhe@newark.rutgers.edu
Lecture notes will be found at:
http://andromeda.rutgers.edu/~huixinhe/cour
ses/course.html
Scanning probe microscopy
The goal of the course will be to introduce the SPM technique
and the frontiers research in nanoscience and technology in ways
that a broad range of students can appreciate and use “nanoconcepts”
and the SPM technique in their own research.
The focus of the course will be on the use of scanning probe microscopy
to extend the scope of traditional areas of research to the revolutionary
nanoscience research and the state-of-art nanotechnology
The learning goal of this course is the basic operation of atomic force
microscope, and operation principle of several basic imaging modes in the
family of scanning probe microscopy and their advanced applications.
Tentative Syllabus and Topics
( may change slightly as we proceed through the semester)
•Overview of scanning probe microscopy, working principles of STM and AFM
and some important parts in the instruments.
•Hands on experience of atomic force microscope
•Toward imaging with the theoretical resolutions.
•More working principles for new imaging mode and their applications
•In-situ electrochemistry of AFM and STM
•Application beyond imaging (1)  Nanoelectronics and molecular electronics
•Application beyond imaging (2)  Nanofabrication
•Application beyond imaging (3)  Single molecular force spectroscopy
•Application beyond imaging (4)  Nanomechanics/chemical and biochemical
detection.
Textbooks
There is no prescribed textbook for the course. Some reference books
and materials are listed below, but more will be provided before each
lecture.
•“Scanning Probe Microscopy and Spectroscopy, theory, techniques and
applications” Dawn Bonnell 2001
•“Scanning Probe Microscopy and Spectroscopy, Methods and
applications” Roland Wiesendanger 1994
•“Atomic Force Microscopy for Biologists” V. J. Morris 1999
•“Intermolecular Surface Forces", J. Israelachvili, Academic Press, 1991
•“Micro/Nanotribology and its applications” Bharat Bhushan 1997.
•“Electrochemical nanotechnology” W.J. Lorenz and W. Plieth 1998
Nanoscience and Nanotechnology
•How big is “ Nano” ? give some examples which are naturally on
the range of nano?
•Could you give some examples how nanoscience and
nanotechnology impact our social and economic life?
Both positive and negative.
•What is the excellent tool for the research of nanoscience?
Scanning Probe Microscopy
Family: AFM, STM, FFM, EFM, MFM etc.
Scanning Probe Microscopy
How does it work?
Compared to other microscopy, this is the only technique
could let you “see”
A blind man is reading! ( without light, but touching)
Brain
braille
braille
braille
braille
braille
braille
braille
braille
braille
braille
A brief history of SPM:
Scanning Tunneling Microscope (STM)
• Developed in 1981 by Binning, Rohrer, Gerber, and Weibel
at IBM in Zurich, Switzerland.
•Gerd Binnig and Heinrich Rohrer have been awarded the
Nobel Prize in Physics 1986
Atomic Force Microscope (AFM)
• Developed in 1986 by Binning, Quate, and Gerber as a collaboration
between IBM and Stanford University.
SPM family
• Scanning Tunneling Microscopy (STM)
• Atomic Force Microscopy (AFM) (Scanning Force Microscopy (SFM)
There are 3 primary modes of AFM:
•Contact Mode AFM
•Non-contact Mode AFM
•TappingMode™ AFM
•Lateral Force Microscopy (LFM)
•Force Modulation Microscopy
•Magnetic Force Microscopy (MFM)
•Electric Force Microscopy (EFM)
•Surface Potential Microscopy
•Phase Imaging
•Force Volume
Conitnue…
•Electrochemical STM & AFM (ECM)
•Scanning Capacitance Microscopy (SCM)
• Conductive AFM ( TUNA)
•Peakforce imaging
•********************
•Scanning Thermal Microscopy (SThM)
•Near-field Scanning Optical Microscopy
(NSOM or SNOM)
•Photon Scanning Tunneling Microscopy
(PSTM)
•Ballistic Electron Emission Microscopy (BEEM)
To “See…”
In-situ Electrochemistry
Au (111) surface
Cu UPD on Au ( 111) surface,
In situ electrochemical STM
Nanofabrication
Au nanodots array
The Logo of Peking University indented on an Au-Pd film
with a modification force of 20 nN
To Probe the electronic behavior
of single molecules —Molecular Electronics
SPM tip
NO2
Z
(sensitive current measurement)
Nanomechanics
Biomolecular detection for biosensors
Molecular Sensors
—Single Molecular Recognition
SPM tip
Attractive force
Ligand
Receptor
Sensitive force measurement
Major components of AFM
•
•
•
•
•
AFM tip/cantilever assembly
Force detection system
Electronic Feedback system
Scanner ( precise position control system)
Vibration damping system
Scanning Probe Microscopy (SPM)
AFM tip, the sharpness determined the resolution of imaging
Materials: Si or Si3N4
Hard, wear resistant,
suit for microfabrication
Tip and cantilevers
JACS 1998 120, 603
Carbon Nanotube sharpened Tip
Carbon Nanotube Tips:
High-Resolution Probes for
Imaging Biological Systems
Charles M. Lieber JACS, 1998, 120, 603
Interactions
Force Detection system
x1
Hook’ law: F= - kx
k: Spring constant of the cantilever
x2
Materials, and dimension of the
cantilever
k increases with lever thickness, decreases with lever length
Position sensitive photodetector
Photodetector: photodiode, turns light into
Electrical signal
Mechanically amplification
Meyuer, H andAmer, N. M. (1988) “ Novel approach to atomic
Force microscopy” Appl. Phys. Lett. 53, 1045-1047
Amplification is determined by the size of the cantilever;
The shorter, the larger the angular displacement of the laser
beam
In theory:
4x10 -4 Å
In practice: random thermal excitation of the cantilever
Piezoelectric Scanners (Scanning Mechanism )
Piezoelectric effect: piezoelectric crystals
The electrical polarization produces is proportional to the stress and the direction.
The polarization changes if the stress changes from compression to tension
Reverse piezoelectric effect
Materials: lead zirconate titanates
( Pb(Ti, Zr)O3) PZT type )
Linear relationship between L and V
Senstivity
hysteresis
Scanners
Vibration isolation—
Crucial to obtaining high resolution image
SPM by nature is sensitive to very small displacement of
The sample or tip.
Building vibration, speaking voice, walking…
Temperature
Atomic Force Microscopy
Force mapping
Very rough surface
Tip crashed or sample destroyed
Smarter imaging ---Need a Feedback system
Youtube:
AFM Principle - How AFM Works
AFM_animation_Vo02.wmv