Even though most microarrays present good quality, accuracy and reliability, they are made on a planar surface structure, which neither enough increases the accessibility of the targets to the probes nor the loading capacity of the solid support. To achieve a high density of reactive functions, the use of a non-planar structure is investigated to increase the available surface area for grafting of biomolecules. We propose to build up a pseudo-three-dimensional silicon structure, covered with a specific oxide layer, and then functionalized, allowing to introduce covalent and stable bindings of amino-modified oligonucleotides probes on the reactive layer of the support. The performances of these supports after silanisation are investigated by means of hybridization experiments using complementary fluorescent labeled-oligonucleotides targets. Our results indicate that these novel surfaces provide a higher specific surface area for attaching biomolecules and higher accessibility of the targets, which will increase the density of biomolecules and hence, the sensitivity of the fluorescence signal in comparison to the results obtained with a planar surface structure.