Abstract: The present invention relates to a method for forming metal-silicide catalyst nanoparticles with controllable diameter. The method according to embodiments of the invention leads to the formation of ‘active’ metal-suicide catalyst nanoparticles, with which is meant that they are suitable to be used as a catalyst in carbon nanotube growth. The nano-particles are formed on the surface of a substrate or in case the substrate is a porous substrate within the surface of the inner pores of a substrate. The metal-silicide nanoparticles can be Co-silicide, Ni-silicide or Fe-silicide particles. The present invention relates also to a method to form carbon nanotubes (CNT) on metal-silicide nanoparticles, the metal-silicide containing particles hereby acting as catalyst during the growth process, e.g. during the chemical vapor deposition (CVD) process. Starting from very defined metal-containing nanoparticles as catalysts, the diameter of grown CNT can be well controlled and a homogeneous set of CNT will be obtained.

Abstract: The present invention relates to a method for forming metal-silicide catalyst nanoparticles with controllable diameter. The method according to embodiments of the invention leads to the formation of ‘active’ metal-suicide catalyst nanoparticles, with which is meant that they are suitable to be used as a catalyst in carbon nanotube growth. The nano-particles are formed on the surface of a substrate or in case the substrate is a porous substrate within the surface of the inner pores of a substrate. The metal-silicide nanoparticles can be Co-silicide, Ni-silicide or Fe-silicide particles. The present invention relates also to a method to form carbon nanotubes (CNT) on metal-silicide nanoparticles, the metal-silicide containing particles hereby acting as catalyst during the growth process, e.g. during the chemical vapour deposition (CVD) process. Starting from very defined metal-containing nanoparticles as catalysts, the diameter of grown CNT can be well controlled and a homogeneous set of CNT will be obtained.

Abstract: The present invention provides a method for forming at least one carbon nanotube (16) by using metal-free catalyst nanoparticles (14), for example Si or Ge comprising nanoparticles. The method uses the step of decomposing a carbon source gas to form carbon fragments which then recombine at the metal-free catalyst nanoparticles (14) to grow carbon nanotubes (16). The method according to embodiments of the invention leads to carbon nanotubes (16) which do not comprise metal impurities.

Abstract: A method for forming catalyst nanoparticles on a substrate and a method for forming elongate nanostructures on a substrate using the nanoparticles as a catalyst are provided. The methods may advantageously be used in, for example, semiconductor processing. The methods are scalable and fully compatible with existing semiconductor processing technology. Furthermore, the methods allow forming catalyst particles and elongate nanostructures at predetermined locations on a substrate.