NOVELTY - Processing a substrate, comprises: receiving a substrate; forming a molecularly self-assembled layer on the surface of the porous dielectric material; processing the molecularly self-assembled layer using one of cleaning, reactive etching, vaporization, annealing or curing the substrate; and forming a barrier layer over the molecularly self-assembled layer after processing the molecularly self-assembled layer.    USE - The method is useful for: processing a substrate, preferably processing a substrate using molecular self-assembly to form one or more layers between a dielectric and electrically conductive materials; and manufacturing an electronic components, flat panel displays, integrated circuits, semiconductor device, optoelectronic devices, data storage devices, magnetoelectronic devices, magneto-optical devices, molecular electronic devices, solar cells, photonic devices and packaged devices, programmable logic devices including field programmable gate arrays, programmable array logic devices, electrically programmable logic and memory devices, standard cell-based devices, and specific integrated circuits.    ADVANTAGE - The method prevents diffusion of foreign material through the exposed pores of porous dielectrics. The molecular self-assembly layer has good pore sealing capability, good adhesion properties (both to the dielectric and to the overlying layer), good diffusion barrier capability and good passivation capability.    DETAILED DESCRIPTION - Processing a substrate, comprises: receiving a substrate, where the substrate comprises a porous dielectric material forming a surface, and the surface comprises hydroxyl groups; forming a molecularly self-assembled layer on the surface of the porous dielectric material, where the molecularly self-assembled layer comprises molecules having chain lengths and head groups selected to seal pores on the surface of the porous dielectric material; processing the molecularly self-assembled layer using one of cleaning, reactive etching, vaporization, annealing or curing the substrate; and forming a barrier layer over the molecularly self-assembled layer after processing the molecularly self-assembled layer, where the molecularly self-assembled layer prevents materials of the barrier layer from contacting the porous dielectric material of the substrate. An INDEPENDENT CLAIM is included for a semiconductor substrate comprising: the porous dielectric material comprising a surface; the molecularly self-assembled layer disposed on the surface of the porous dielectric material; and the barrier layer disposed over the molecularly self-assembled layer.