A first layer on a substrate includes an insulator material portion adjacent an energy-reactive material portion. The energy-reactive material portion evaporates upon application of energy during manufacturing. Processing patterns the first layer to include recesses extending to the substrate in at least the energy-reactive material portion. The recesses are filled with a conductor material, and a porous material layer is formed on the first layer and on the conductor material. Energy is applied to the porous material layer to: cause the energy to pass through the porous material layer and reach the energy-reactive material portion; cause the energy-reactive material portion to evaporate; and fully remove the energy-reactive material portion from an area between the substrate and the porous material layer, and this leaves a void between the substrate and the porous material layer and adjacent to the conductor material.