Non-thermal deposition of films and structures

Si/Ge nanocolumns, synthesized on a Si substrate with glancing angle deposition (GLAD)

Centre of the research work is to examine and to clarify growth processes of thin films and nanostructures by using deposition techniques, with which these processes take place far from thermodynamic equilibrium. In this way, application-relevant optical, electronic, mechanical or magnetic properties of such films or nanostructures can be significantly modified or optimized.

Three distinct physical synthesis routes are followed for the growth of functional thin films and nanostructures with modified or optimized properties:

  • Ion-beam assisted deposition (IBAD) or ion-beam assisted molecular beam epitaxy (IBA-MBE)
  • Pulsed laser deposition (PLD)
  • Ion-beam or electron-beam based glancing angle deposition (GLAD) / oblique angle deposition (OAD)

Both IBAD/IBA-MBE as well as PLD take advantage in particular of the positive effects of the hyperthermal species being involved in the film deposition process. In contrast, GLAD/OAD is used as a constructive method for synthesis of nanostructures and highly porous thin films. This is realized by growth with a well-defined restriction of degrees of freedom, i.e. the time-dependent selection of the deposition geometry widely defines the achievable structures and their properties.

The investigations of the respective growth processes upon the synthesis of a variety of material systems are conducted with the aid of modern in situ and ex situ analysis methods. This serves on the one hand the augment of the fundamental understanding of energetic particle enhanced deposition processes as well as of the influence of the deposition geometry on structure formation and on the other hand the corresponding technology optimization.

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