Effects of plasma treatment on high-field conduction and breakdown of poly-p-xylylene thin films

The high-field behavior and breakdown of poly-p-xylylene (PPX) thin films into which defects were introduced by treatment in an Ar plasma were studied. Some of the defects act as scattering or trapping centers. The high-field current in the film was suppressed considerably by the plasma treatment. The plasma treatment increased the breakdown strength of PPX from 7 MV/cm to 10 MV/cm. A comparison between results for poly-2-chloro-p-xylene (PCPX) and the plasma-treated PPX films revealed that some of the defects introduced by the treatment suppressed the high-field current more effectively than the chlorine atoms in PCPX. Moreover, the plasma treatment raised the breakdown strength of PPX without a large increase in dielectric loss.<>