Ph. D. THESIS 2009

2. Experimental part: fabrication and characterization
The process of micro/nanofabricationby TPA consists of three main parts from
the experimental point of view: the chemical part, the properly metallic
fabrication part, and the metallic structures characterisation part.
The chemical part involves sample preparation, glass substrate coating by a
polyimide adherent layer, and preparation of thin films (from aqueous
solutions) by spin-coating. The metallic fabrication process requires the
performance of a complex experimental set-up in order to deliver the laser
beam within the sample active layer. The characterisation of nanostructures
involves the use of optical and spectroscopic techniques, correlated with
scanning electron microscopy (SEM) and atomic force microscopy (AFM).
Figure 2 presents a section view of the laser beam way inside the microscope
which illustrate its interaction with the sample.
Laser beam
Figure 2. Inside view of the microscop-enlarging of the sample
3 Optimisation of silver nanostructures fabrication
Silver is a well-known soft white lustrous noble metal, characterised by the
highest electrical and thermal conductivity for a metal as well as by its
oxidizable character
Different techniques using light to fabricate silver were developed because its
already known and remarcable applications in photographic art as well as for
the new applications in nanophotonics and nanoelectronics. These new topics
are related with the surface plasmon properties of silver and particulary with
their surface-enhanced Raman effect which increases the Raman measurement
by order of magnitude [8,9].
3.2. TPA approach of silver photographic process
1