Patent ID: 8236684

Claim:
A method of processing a substrate having a patterned porous dielectric layer deposited thereon, the porous dielectric layer having openings with sidewalls and bottom portions, the method comprising: forming a conformal pore-sealing layer over the substrate by a plasma assisted ALD process, the pore-sealing layer contacting the porous dielectric layer on at least the sidewall portions of the openings; removing a portion of the conformal pore-sealing layer covering the bottom portions of the openings by performing a directional etch process; cleaning the substrate by performing a wet-clean process; and filling the openings with a conductive material, wherein the plasma assisted ALD process comprises exposing the substrate to a first gas mixture comprising hexamethylcyclotrisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane (OMCTS), or 1,3,5,7,9-pentamethylcyclopentasiloxane.