Fundamentally plasma is defined as a chaos, with the presence of several ionic precursors in random Scriptaid distribution. There are constructive molecules which help in the structuring of the thin film, also there are ions or radicals which perturb the growth continuity or etch away the material from the surface . In case of (CH4 + H2) gas mixture various CHn radicals mostly constitute growth precursors, while atomic H etches the material heavily . In addition to the effect of the atomic H, the surface of the material also gets damaged by the bombardment of the highly energetic ionic particles . Accordingly, convenient means of controlling the deteriorating effects of plasma on the film surface, without compromising the film quality, could be of significant importance.
One way to reduce the effect of direct-plasma is to use the remote-plasma configuration  and , as at a growth site distant from the plasma the energetic ionic particles significantly reduce in number density. Alternatively, if by some means the aggressiveness of the plasma could be tuned down to lower and less hostile level by some tricky arrangement in secondary plasma, the bombardment of the highly energetic particles or effect of the etching elements could be restricted. Secondary plasmas have reduced concentration and energy of the active species  and  and could be used for materials that may be sensitive to some or all of the components in the aggressive plasma.