METHOD OF SELECTIVE DEPOSITION FOR BEOL DIELECTRIC ETCH

Embodiments of the invention address several issues and problems associated with etching of dielectric materials for BEOL applications. According to one embodiment, the method includes providing a patterned substrate containing a dielectric material, exposing the substrate to a gas phase plasma to functionalize a surface of the dielectric material, exposing the substrate to a silanizing reagent that reacts with the functionalized surface of the dielectric material to form a dielectric film, and sequentially repeating the exposing steps at least once to increase a thickness of the dielectric film. According to one embodiment, the dielectric material may be a porous low-k material, and the dielectric film seals the pores on a surface of the porous low-k material.