Abstract
The high-field currents in poly-p-xylylene (PPX) thin films have an anode metal dependence and a negative temperature dependence. They are accompanied by electroluminescence. They are explained in terms of hole injection from anode metal and collision ionization (or electronic avalanche).
In this paper, the authors attempted and discussed the improvement of insulation thin films by chemical or physical modifications. Chlorine atoms in poly2-chloro-p-xylylene (PCPX) thin films suppressed high-field currents and raised the electric strengthes (8.4 MV/cm) in the low tempera ture region. Mean free pathes in PPX and PCPX films are 6.5 nm and 3 nm, respectively. It is clear that the probability of carrier scattering in PCPX is higher than that in PPX, because there are polar groups C-C1 in, PCPX. Plasma treatment introduced some defects and oxidation products in PPX thin films. It strongly suppressed high-field currents in PPX and resulted in a high dielectric strength(-10MV/cm)in all temperature region. Both plasma modification and ozone oxidation also suppressed hole injection from anode. Especially, the latter was more effective to improve the electric strength.
