A boiler that enhances the efficiency of the use of heated gas streams to generate steam is provided. In one embodiment, a substrate is provided with a sacrificial layer disposed on a hard mask layer, and a metal layer disposed in a trench of the substrate and on the sacrificial layer. The frequency and type of inspection is tailored to items important to a facility manager, such as the importance to the operation of individual component-sections and their individual life cycle, not the overall life cycle of a system or facility. A top dielectric layer which includes top via openings in communication with the top level conductive lines is formed over the top metal level. Thus, by using a diamond film as the barrier layer, diffusion of the copper from the conductive layer into the material of the substrate is substantially reduced and preferably eliminated.