High-field phenomena in poly-p-xylylene thin films: effects of plasma treatment

Plasma treatment has greatly suppressed high-field current and electroluminescence in poly-p-xylylene (PPX) thin films prepared by Gorham's method. The breakdown strength of plasma-treated PPX (P-PPX) was about 10 MV cm -1 and higher than that of PPX or poly-2-chloro-p-xylylene (PCPX). In addition, the dielectric loss of P-PPX was almost the same as that of PPX and it was low compared to that of PCPX. The ESCA spectra showed that there is some oxidation on P-PPX surfaces. It was suggested that the oxidised P-PPX surface layer suppressed hole injection from anode metals in P-PPX. These results suggest that plasma treatment suppressed collision ionisation in PPX and hole injection from anode metals more effectively than chlorine atoms in PCPX.