RSGP mechanisms

Rapid Step-Growth Polymerization (RSGP) Mechanism... 

Any species involved in the RSGP mechanisms (Fig. 5.3) can deposit on the substrate surface. Deposition occurs when an impinging particle fails to bounce back from a colliding surface. Such a deposition may result from the loss of kinetic energy or from the formation of a chemical bond with a target molecule or atom. The sticking coefficient, or deposition coefficient, can be defined as the number of particles deposited divided by the total number of impinging particles. 

The bicyclic RSGP mechanism shown in Figure 5.3 has an important implication for the interpretation of diagnostic data of the luminous gas phase. Namely, any species identified in the plasma phase are intermediate species of step growth polymerization but not precursors of black box plasma polymerization. 

A less widely quoted scheme is the activated growth mechanism (AGM) of d Agostino and coworkers developed to describe fluorocarbon deposition. In the AGM CF radicals stick onto activated sites on the depositing polymer surface. The activation is triggered by low energy positive-ion bombardment. The deposition rate is described as first-order with respect to the CF species and a complex function,/(I ), which represents both the ion flux and energy in positive-ion bombardment. This model may have more relevance in lower power plasmas than the RSGP. 

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