Nanowires constitute the potential building blocks for the emergence of new architectures in nanoelectronics and sensors applications as they exhibit different material properties from their corresponding bulk structures. Manipulating nanowires to locate them at a desired position is therefore a crucial issue in view of developing large scale nanosystems. The technique reported in this thesis combines dielectrophoresis phenomenon and capillary assembly to successfully align hundreds of single nanowires at specific locations on a wafer in a more straightforward and affordable procedure than what's proposed at the state of the art. A non-uniform electric-field applied between interdigitated electrodes induces a polarization on dielectric particles such as nanowires. The resulting force (DEP force) makes the nanowires able to move in the solution while the capillary assembly ensures both a convective flux of nanowires towards the alignment sites and the final orientation of the nanowires in the axis of the electrodes as the solvent dries. This protocol has been designed on a 6-inches wafer and thus is scalable very easily. It is efficient for single-level alignment but also for creating dense parallel arrays of nanowires if required. High-level level integration can be achieved by combining two steps of alignment with two different materials as silicon and InAs. This assembly technique is versatile as DEP electrodes can be implemented on various substrates such as flexible substrates or directly integrated in the back-end of circuits. It also offers independent post-processing processes which are completely uncorrelated from the alignment step as the underneath DEP electrodes are isolated from the surface by a planarized dielectric layer. Once the nanostructures are aligned, specific contact studies and electrical characterization can be performed as the previous steps for innovative devices. The electrical contact on a nanowire is examined in order to distinguish the contact resistance from the nanowire resistance. Finally, as a proof of concept, we developed 2 applications based on semiconducting nanowires : transistors and gaz sensing devices. This work appears as a real step towards nanowires integration and opens new outlooks to promising applications.
Manipulation et adressage grande échelle de nanofils semiconducteurs pour la réalisation de nanosystèmes Innovants