Growth vs. nucleation of conducting polymers thin films obtained by plasma-enhanced chemical vapor deposition

When dealing with conducting polymers it is important to control the growth to obtain the desired uniformity. With plasma-enhanced chemical vapor deposition, highly uniform and pin-hole free thin films can be achieved by promoting the growth processes in detriment of the nucleation processes. This can be done by different means: decreasing the power of the radio-frequencies that generate the plasma so that less monomers are ionized or by using pulsed plasma CVD. Pyrrole and thiophene are the monomers that have been used. The range of RF power used is from 4 to 10 W of continuous RF and pulsed RF (t _on = 6 ms, t_off = 6 ms). Samples have been taken at different times over a period of an hour and have been examined by AFM. The results show that the morphological characteristics of thin films obtained on the lower power are better than those obtained on the higher power. It has been demonstrated that the layer growth of both conducting polymers can be controlled using pulsed plasma.