Abstract FR:

The aim of this thesis is to report the results of an investigation aimed at exploiting synthetic methods to graft organic molecules onto (001) Si as well as at evaluating the applicability of SAM docking in the development of nanodevices. The target of this dissertation is to study a new nucleophylic reaction to bond directly the organic molecules at the surface. In the first part of this work we have focused onto silicon surface preparation. We have pointed out how the RCA cleaning method results in a modification of the structure of the first atomic layers of Si. We have demonstrated by HRTEM and EELS studies that the change of the lattice spacing is related to the subsequent Si oxidation that is known to occur by inward diffusion and insertion of oxygen in bond-centred positions in crystalline silicon. Such a process is favoured by the strain field due to the surface roughening which is characteristic of alkaline etches. To activate the surface toward chemical grafting reactions we have developed a method leading to bromine termination of the surface. This allowed to form an array of aromatic rings bonded through a covalent Si-C bond (i. E. Not implying oxygen bridges) by nucleophilic addition onto the Si-Br surface bond. We have evaluated the bromine termination and the surface reconstruction by Auger, FTIR and LEED analyses. . .