The organization of carbon nanotube and silicon nanowires using lateral-type porous anodic alumina

We successfully synthesized organized Carbon nanotubes (CNTs) and Silicon Nanowires (SiNWs) arrays using LPAA. This approach can yield very dense assemblies of nano-objects with a planar-type organization compatible with existing tools inherited from advanced microelectronic processes and adapted to electronic devices as field effect transistors, interconnects, sensors, etc. CNTs/SiNWs were grown using Hot-filament Chemical Vapor Deposition (HFCVD) within lateral-type porous anodic alumina. We demonstrate that the pulsed electrodeposition of metal nanoparticles to be further used as catalysts inside the membranes requires specific thinning and pore widening process to remove the alumina barrier layer located at the bottom of the pores. The growth of CNTs was found to strongly depend on the electrodeposition conditions as well as on the CVD parameters. In addition, we found that introducing atomic hydrogen (generated using a hot-wire) as etching agent was essential to prevent parasitic carbon/silicon deposition on the surface of PAA or on the wall of pores and to improve CNTs/NWs growth. Such organized CNTs/SiNWs arrays are very promising as advanced microelectronic devices and their potentiality for photosensing applications were investigated.