NOVELTY - Passivating at least a part of a surface of a semiconductor substrate comprises: placing the substrate (1) in a process chamber (5); maintaining the pressure; contacting at least a part of the plasma (P) with the part of the substrate surface; and supplying at least one precursor suitable for the a-Si:H passivation layer realization to the part of the plasma (P) via injection nozzles (19) of an injector device (17).    USE - The method is useful for passivating surface of semiconductor substrate (claimed).    DETAILED DESCRIPTION - Passivating at least a part of a surface of a semiconductor substrate, where at least one layer comprising at least one a-Si:H passivation layer is realized on the part of the substrate surface by: placing the substrate (1) in a process chamber (5); maintaining the pressure in the process chamber (5) at a vacuum pressure; maintaining the substrate (1) at a substrate treatment temperature suitable for realizing the layer; generating a plasma (P) by at least one plasma source (3) mounted on the process chamber (5) at a distance (L) from the substrate surface, at least part of the plasma (P) being injected into the chamber (5) and achieving a supersonic speed; contacting at least a part of the plasma (P), injected into the chamber (5), with the part of the substrate surface; and supplying at least one precursor suitable for the a-Si:H passivation layer realization to the part of the plasma (P) via injection nozzles (19) of an injector device (17), so that the density of the precursor at each injection nozzle (19) is lower than 12x1022 particles/m3. INDEPENDENT CLAIMS are:    (1) an apparatus for realizing at least one layer onto at least part of a surface of a substrate comprising: a process chamber (5), having a substrate holder for holding a substrate; at least one remote plasma source (3) mounted on the process chamber (5) at a distance from the substrate holder, for generating a plasma that expands into the chamber (5); an injector device for supplying at least one precursor suitable for layer realization to the expanding plasma (P); where the injector device is provided with more than fifteen separate precursor injection nozzles; and    (2) a solar cell, provided with at least a part of a substrate at least obtained with a method.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the substrate treatment apparatus.    Substrate (1)    Plasma source (3)    Chamber (5)    Substrate holder (8)    Fluid supply system (16)    Injector device (17)