A study of plasma-polymerized aniline films

Abstract

Summary form only given, as follows. Thin films of electroactive polymers have several important applications in the fields of mechanics, electronics and optics. Among the several methods used to produce these films, plasma enhanced CVD may be an important technique. Others have shown that plasma-polymerized films exhibit electroactive properties. It is well known that plasma polymerized thin films can easily be made pinhole-free. Pulsing the RF field is known to result in a high degree of control of plasma-polymerized film chemistry. We model the plasma polymerization of aniline carried out in a custom-built pulsed PECVD reactor, the details of which have been published elsewhere. Some electrical properties of the plasma-polymerized aniline (PPAni) films are being studied by fabricating parallel plate devices. This structure consists of a PPAni thin film sandwiched between two metallic electrodes with widely differing work functions. Results from AC impedance, transient capacitance, volt-ampere and ellipsometric measurements yield important information regarding the electrical permittivity and conductivity of the PPAni films. Comparison of these films to conventionally polymerized films is made using surface and structural characterization studies such as electron microscopy, IR spectroscopy and NMR spectroscopy. The influence of plasma conditions on device properties is studied. For example, a doping species is introduced into the feed stream. The impact of the dopant on film properties and device characteristics is measured. The study can make important contributions to the development of a new generation of devices based on plasma processing of organic thin films.