Relationship between the Binding Energy and Boundary Condition in SiOC Film for ILD Application

Abstract

Low dielectric constant SiOC film was deposited by the chemical vapor deposition. To research the change of polarization by the chemical reaction between opposite polar sites, the synthesized SiOC films at various flow rates of BTMSM were studied by Fourier Transform Infrared Spectroscopy, X-ray diffraction patterns, X-ray photoelectron spectroscopy, and Scanning Electron Microscope. By using these analytical methods, the correlation between the chemical shift and boundary condition on surfaces of SiOC film was observed. The binding energies of Si 2p, C 1s, and O 1s in SiOC film with the low polarization were higher than other films, and the 2θ value in X-ray diffraction pattern was also moved to the higher degree in the film of the lowest polarity. The chemical shift was caused by the polarization due to the lowering of the ionic polarization by the chemical reaction between alkyl and hydroxyl group as polar sites. The Scanning Electron Microscope of SiOC film showed an image of flat surface without pin-holes due to the low surface energy, which improves the properties of SiOC film to become an ideal low-k material. On the other hand, SiOC film with low binding energies of Si 2p, C 1s, and O 1s displayed the pin-holes in SEM images owing to the existence of polar sites. The grain boundary such as pin-holes indicates that an unbalance exists in the uniformity of electron distribution on a surface and a low degree of amorphism.