High-field current and breakdown in poly-2-chloro-p-xylylene and poly-p-xylylene composite thin films: the remarkable negative temperature dependence of current

• Published in: Journal of physics. D, Applied physics Vol. 26; no. 1; pp. 83 - 88
• Main Authors: Mori, T, Matsuoka, T, Mizutani, T
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 14.01.1993; Institute of Physics
• Subjects: Applied sciences; Electrical, magnetic and optical properties; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; Composite film; Breakdown voltage; Electrical properties; Xylene polymer; High field; Temperature effect; Chlorine containing polymer; Experimental study; Current density; Thin film
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/26/1/013

The high-field currents in poly-p-xylylene (PPX) and poly-2-chloro-p-xylylene (PCPX) thin films are caused by hole injection from anode metal and collision ionization. Since chlorine atoms in PCPX act as carried scattering centres, high-field currents in PCPX thin films are suppressed in the low-temperature region and their breakdown strengths also increase. In the case of PCPX/PPX composite thin films where PCPX thin films (d < 150 nm) are deposited on PPX thin films of (d > 200 nm), their high-field currents were strongly suppressed around room temperature, but not in the low-temperature region. Therefore high-field currents in PCPX/PPX thin films showed a remarkable negative temperature dependence. High-field currents were more suppressed in PCPX (60 nm)/PPX (230 nm) composite thin film than in PCPX (130 nm)/PPX (230 nm). This can be explained by the suppression of hole injection from anode by homo space charge near the interface between PCPX and PPX. The breakdown strength of PCPX/PPX thin film had a positive temperature dependence and was higher than that of PPX thin film around room temperature.