Process for depositing, by electron cyclotron resonance plasma, a web of carbon nanofibres or nanotubes onto a substrate without any catalyst, comprising:
- injecting of a microwave power into a deposition chamber having a magnetic structure with an unbalanced magnetic mirror and at least one electron cyclotron resonance zone within an interior of the deposition chamber itself and opposite the substrate;
- inducing under a pressure less than or equal to 10−4 mbar, at least one of ionization and dissociation of a gas containing carbon in the magnetic mirror in a center of the deposition chamber and
- producing species that deposit on the substrate, which is heated.