Multilayer Cu/SiC(O)N/dense SiOC(-H)/porous SiOC(-H)/p-Si(100) thin-film stacks were fabricated. A 200-nm-thick porous SiOC(-H) film was deposited on an Si substrate using plasma-enhanced chemical vapor deposition. Subsequently, a 60-nm-thick dense SiOC(-H) film followed by a 20-nm-thick SiC(O)N film was deposited using plasma-enhanced atomic layer deposition. These multilayer films were then irradiated with ultraviolet (UV) light at 400 degrees C for various times in the range 5 to 20 min to improve their structural, mechanical, and electrical properties. The effects of the UV radiation on the interfacial bonding configurations and the mechanical properties of the interface between the SiC(O)N etch stop layer and the porous low-k SiOC(-H) film were investigated. The elemental concentrations of Si, C, N, and O were determined at the SiC(O)N/SiOC(-H) interfaces using Auger electron spectroscopy depth-profile analysis, and the electrical properties of the Cu/SiC(O)N/SiOC(-H)/Si metal-insulator-semiconductor structures were investigated using capacitance-voltage and current-voltage profiling. Based on our experimental results, UV exposure for 5 to 10 min is optimal for improving the characteristics of Cu/SiC(O)N/SiOC(-H)/Si multilayered films. (C) 2013 Elsevier B. V. All rights reserved.