A scanning electron microscope study of plasma‐polymerized organosilicon films suitable for use as lightguides. A determination of the cause of signal attenuation

Abstract

The scanning electron microscope was used to evaluate the optical quality of a plasma‐deposited organic film. A major source of signal attenuation in lightguide films results from scattering by microscopic embedded spheres. The spheres are produced in the gas phase, and their size and population density are a function of the substrate surface and the rate of film formation. For all systems studied, the number of spheres increase with increasing rate. High‐quality films were deposited more easily on silicon, silicon dioxide, tungsten, and glass than on Nichrome or β‐tantalum. Gold, copper, and titanium surfaces proved more difficult, while aluminum was the most intractable material encountered. The rate of film growth usually increased with an increase in power input for any ratio of total pressure‐partial pressure of monomer. Spheres were essentially eliminated or their number reduced to a tolerable level by a proper choice of reaction conditions.