UV assisted silylation for porous low-k film sealing
Embodiments described herein provide a method for sealing a porous low-k dielectric film. The method includes forming a sealing layer on the porous low-k dielectric film using a cyclic process. The cyclic process includes repeating a sequence of depositing a sealing layer on the porous low-k dielectric film and treating the sealing layer until the sealing layer achieves a predetermined thickness. The treating of each intermediate sealing layer generates more reactive sites on the surface of each intermediate sealing layer, which improves the quality of the resulting sealing layer.
1. A method for forming a sealing layer, comprising:
delivering UV energy to a substrate disposed in a process chamber, wherein a porous low-k dielectric film is disposed on the substrate;
forming an intermediate sealing layer, wherein forming the intermediate sealing layer sequentially comprises:
flowing a first precursor compound into the process chamber while delivering UV energy to the porous low-k dielectric film disposed on the substrate, wherein the first precursor compound comprises acetoxytrimethylsilane or dimethylaminotrimethylsilane;
stopping the flow of the first precursor compound;
flowing a second precursor compound into the process chamber while delivering UV energy to the porous low-k dielectric film disposed on the substrate, wherein the second precursor compound comprises diacetoxydimethylsilane or bis(dimethylamino)dimethylsilane; and
exposing the substrate to UV energy after flowing the second precursor compound to cure the intermediate sealing layer; and
repeating the forming of the intermediate sealing layer to form additional intermediate sealing layers.
2. The method of claim 1 , wherein the sealing layer has a thickness from about 5 Angstroms to about 200 Angstroms.