Method and apparatus for sequential plasma treatment

Method for plasma treatment of a hollow (1; 10) substrate comprising the steps of: a) placing a plurality of sources of ionization energy (7 to 10; 107 to 112) all along the part the substrate to be treated, b) injecting a process gas inside the substrate, said gas containing a precursor for plasma creation, c) maintaining pressure inside the tube within a predetermined range, wherein further comprising the step of: d) powering from a single energy source radio frequency (6; 106) the sources of ionization energy, in sequence, to create selectively plasma inside the substrate in a situation corresponding to the respective energized source, repeating said step b) of injecting the process gas at least prior to the energization of each ionization source of energy, supplying said single power source radio frequency energy at frequencies between 10 kHz to about 100 MHz.