The idea of the following text is to give a short introduction to the topic of nanoscience and nano technology,giving an access to more detailed texts.
As a short introduction to the above topics especially in the field of semiconductor physics, we provide a short movie in high(77MB) and low(18MB) quality (sorry, only in german).

What is nanotechnology?

A nanometer (nm) is one billionth of a meter or 10-9 meter. The relation between nanostructures and the size of a football is the same as between the football and the earth. Nanotechnology is the fabrication of materials or systems, where at least one dimension is in the range of 1-100nm. By manipulating matter at this length scale one hopes to achieve superior electrical, chemical, mechanical and optical properties of these material for applications in our macroscoic world.

Fabrication of nanostructures

In principle there are two different methods to produce nanostructures:

Top Down

The most common way to fabricate structures in the range of nanometers it the top-down approach. By using lithographic processes the small nanostructured elements are "cut" from larger pieces. The best known example is microelectronics.Today using optical lithography semiconductor chips with critical dimensions down to 65nm can be produced. Because of the limited resolution due to the wavelength of the light already now special tricks have to be used (such as phase shift masks). To realize structures in the range of 1nm electron beam lithography is used.

Bottom Up

The bottom-up approach utilizes methods of selforganization on molecular and nanocrystalline levels. The most impressive examples can be found in biology, e.g. the replication of DNA strands or the selforganization of proteins.
The principle of selforganization is not resticted to biological systems, but it can be used in principle in arbitrary atomic or molecular systems, e.g. for the synthesis of nanocrystalline materials and selforganized semiconductor nanostructures.

Visulisation of nanostructures

In an optical microscope the size of the smallest visible structure is in the range of the wavelength of the light (due to it wave properties). Therefore nanostructures are not visivle in optical microscopes.
There are several different methods to characterize Nanostructures, some of them will be presented here.
In a Transmission Electron Microscope (TEM) electron beams are used for imaging. Single atomic rows can be made visible and distances belwox 0.1nm can be measured.
In a Scanning Tunneling Microscope (STM) or Atomic Force Miocroscope (AFM) a sharp tip is scanned over the surface. In an STM a current is measured, in an AFM the force between tip and sample surface (van der Waals force). With both microscopes single atoms can be made visible.

What do we need nanotechnology for?

Nanotechnology makes it possible to fabricate smaller, faster computer chops for more efficient computers, mobile phones or navigation systems.
It leads to new lasers like the quantum dot laser which enable faster communication an new powerful data storage systems. The quantum computer is a goal physicists all over the world are working on.
But nanotechnology does not only bring imrovements in the area of semiconductor technology and microelectronics. The mastery of materials and systems on the nanometer scale will also revolutionize traditional areas. Nanostructured metallic and ceramic materials are more buoyant, stronger and more rugged. Carbon nanotubes are more elastic and robust than steel. Polymeres mechanically strengthened with carbon nanotubes are used in areas from medicine to aviation. Nanostructured surfaces are efficinet catalysts. They are used in chemical engineering and in environmental sector.
One of the most interesting areas is the combinatio of nanotechnology and biology. Scientists work with the methods of physics on a molecular level, e.g. on DNA strands or on living cells, so that single functionalities can be investigated, such as the interaction between an cell and a pathogenic germ. Diseases can be diagnosed more easily and custom made drugs can be developed hidering the pathogen to attack the cell, while showing no side effects.