NOVELTY - The process comprises forming metal aggregates (3) on a metal oxide (2) substrate (8), growing nanostructures (1) on the substrate covered with metal aggregates by plasma-enhanced chemical vapor deposition, and heating the substrate in presence of gas precursors. The formation of metal aggregates comprises a reduction operation of the surface of the substrate using reduced plasma treatment thus forming metal aggregate droplets on the substrate surface. The formation of metal aggregates and growth of nanostructures are performed successively in single plasma reactor (4) enclosure.    USE - The process is useful for production of nanostructures including silicon, germanium, silicon-germanium, silicon carbide, carbon or silicon nitride on a metal oxide substrate, where metal oxide includes tin oxide, zinc oxide, indium tin oxide or indium trioxide (all claimed) and the nanostructures are carbon nanotubes and semiconductor nanowires, which are useful in the field of electronics e.g. in thin film transistors and photonics e.g. in solar cells and electroluminescent diodes and optoelectronics and useful as sensors.    ADVANTAGE - The process is capable of economically, easily, rapidly and controllably producing the nanostructures on the metal oxide substrate in large scale with improved electronic- and optoelectronic properties and without using any additional catalysts, and avoids any pollution and oxidation of aggregates by air during the transfer of substrate.    DETAILED DESCRIPTION - The process comprises forming metal aggregates (3) on a metal oxide (2) substrate (8), growing nanostructures (1) on the substrate covered with metal aggregates by plasma-enhanced chemical vapor deposition, and heating the substrate in presence of gas precursors. The formation of metal aggregates comprises a reduction operation of the surface of the substrate using reduced plasma treatment thus forming metal aggregate droplets on the substrate surface. The formation of metal aggregates and growth of nanostructures are performed successively in single plasma reactor (4) enclosure. The metal oxide substrate is heated to a temperature greater than or equal to the melting point ( less than or equal to 300 degrees C) of the metal composing the metal oxide. The metal oxide layer is discontinuous, and comprises metal oxide patterns. The precursor gas is diluted in a dilution gas such as hydrogen that limits the amorphous element deposition outside the metal aggregates by etching. The plasma treatment includes injecting gaseous hydrogen inside the plasma reactor, and generating plasma inside the reactor enclosure for a time duration (t), where the diameter of metal aggregate droplets depends on the time t. The plasma reactor is a radio frequency plasma-enhanced chemical vapor deposition reactor, and has a hydrogen pressure of 180-1000 mTorr for 3 min for plasma generation and density of 10-1000 mW/cm2.    DESCRIPTION OF DRAWING(S) - The figure shows a plasma reactor in which the nanostructures are grown in vapor phase.    Nanostructures (1)    Metal oxide (2)    Metal aggregates (3)    Plasma reactor (4)    Substrate. (8)