Role of Nano-Porosity in Plasma Enhanced Chemical Vapor Deposition of Hermetic low-k a-SiOCN:H Dielectric Barrier Materials

摘要

Critical thresholds for the diffusion of water through low-k a- SiOCN:H dielectrics were investigated using a combination of xray reflectivity (XRR) mass density and positronium annihilation lifetime spectroscopy (PALS) pore size metrologies. It was observed that hermetic low-k a-SiOCN:H dielectrics were achieved only at mass densities >2.2 g/cm~3 and when the PALS pore size is less than or equivalent to the molecular diameter of water.