Design and characterization of a plasma chamber for improved radial and axial film uniformity

AbstractFilm uniformity is an issue in many deposition processes, especially in substrates with elongated lateral dimensions such as fibers. In this study, a plasma chamber was designed with dual electrodes to improve the uniformity of plasma polymer films. Plasma‐polymerized acrylic acid films were deposited via single‐electrode or double‐electrode configurations onto silicon wafer pieces placed at the center of the chamber to mimic the potential position of a fiber. A radial and spatial map of film chemistry and thickness throughout the chamber was determined which demonstrated improved radial uniformity and film stability using the dual‐electrode configuration, thus highlighting the importance of spatial characterization when designing a reactor for the coating of three‐dimensional objects such as fibers.