Conformal dielectric films on silicon nanowire arrays by plasma enhanced chemical vapor deposition

In this article, we describe the coating of silicon nanowire arrays with thin dielectric layers using Plasma Enhanced Chemical Vapor Deposition (PECVD). The impact of deposition pressure, temperature, and nanowire array density on the silicon oxide coating thickness uniformity was assessed using a detailed electron microscopy observations of the nanowire arrays. Deposition rates were found to vary along the nanowire length as a function of the above process parameters, and ranged from 0 to 35 nm/min. The coating thickness was found to be most uniform at higher pressures and temperatures, and high-density nanowire arrays with smaller nanowire diameters and larger lengths led to the deposition of coating with a smaller thickness gradient along the wire length.