Page 188 - Science at the nanoscale

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Nanotools and Nanofabrication
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Feedback control for Piezotube
Piezotube with
Current
Control and
Amplifier
Scanning Unit
tip
Tip
Display and
Data Processing
Voltage
Sample
Ground
Schematic diagram of a Scanning Tunneling Microscope.
Figure 8.18.
Scanning Tunneling Microscopy
8.3.1
The STM was invented by Gerd Binnig and Heinrich Rohrer
from IBM Zurich Lab in Switzerland in 1981. In their seminal
1
paper, they described the construction of the first STM where
a sharp needle was used to probe the surface of a piece of
silicon. The instrument was able to achieve atomic resolution and
revealed the ordered arrangement of Si atoms on the surface of
the sample. This outstanding work won them the 1986 Physics
Nobel Prize. The invention of STM opened a new window to the
world of nanoscience and nanotechnology, whereby surfaces can
be imaged atom-by-atom in real space. STM has since developed ch08
into an important tool in physics, chemistry, biology, engineering
and materials science.
The working principle behind the operation of the STM is quan-
tum tunneling (cf. Chapter 3). Figure 8.18 shows the schematic
of a typical setup for a STM. The most critical component of a
STM is the sharp tip used in imaging the sample surface. Usu-
ally the sharp tip is prepared so that there is a single atom that
protrudes at the tip. When the tip is brought very close to surface
1 G. Binnig, H. Rohrer, Ch. Gerber and E. Weibel, Appl. Phys. Lett. 40, 178–180
(1982).