Process for preparing thin layers of nanoporous dielectric materials

Abstract

Process for preparing a thin layer of a nanoporous dielectric material with homogeneous porosity in which the following successive steps are performed: a first thin layer of a first oxygen-free material, including Si, C and optionally one or more other atom(s) chosen from H, N and F is deposited on a substrate, under conditions so that said first thin layer has a composition making it possible to generate a gas in a subsequent foaming treatment; on the first layer, a second thin layer so-called crust of a second material including Si and at least one other atom chosen from O, C, N, F and H is deposited under conditions so that said second thin layer has a composition that does not make it possible to generate a gas in the subsequent foaming step, and a sufficient density to limit or prevent the spread, diffusion, of the gas generated in the first layer during the subsequent foaming treatment; the first layer and second layer assembly is treated under conditions so that a gas is generated in the first layer in order to enable the foaming thereof and the creation of nanopores therein; the second thin layer is optionally removed. Thin layer thus obtained. Use of the thin layer as an insulation dielectric in metal interconnections. Use of the thin layer to produce air gap structures present in interconnections.

Dependencies are inferred from the claim text.