Composite inter-level dielectric structure for an integrated circuit

Abstract

A method is provided for making an inter-level dielectric for a microelectronic device formed on a substrate. The method begins by forming first and second spacer layers over a substrate layer. The spacer layers are formed from a sacrificial dielectric material. Next, first and second dielectric layers are formed on the first and second spacer layers, respectively, such that each of the first and second dielectric layers is separated by one of the spacer layers. The first and second dielectric layers each include a first and second dielectric component. The second dielectric component is a sacrificial dielectric material. At least a portion of the second dielectric component is removed to thereby form voids in the first and second dielectric layers. At least a portion of the sacrificial dielectric material in the first and second spacer layers is also removed to thereby form voids in the first and/or second spacer layers.