Deposition and characterization of porous low-dielectric-constant SiOC(-H) thin films deposited from TES/O2 precursors by using plasma-enhanced chemical vapor deposition

Low-dielectric-constant SiOC(-H) thin films were deposited on p-type Si(100) substrates by using plasma enhanced chemical vapor deposition (PECVD) from triethoxysilane (TES; C6H16O3Si) and oxygen gas as precursors. A detailed characterization, such as the chemical structure, bonding configurations and dielectric constant (k), of the SiOC(-H) films was performed. A possible mechanism responsible for the reduction in the dielectric constant of the SiOC(-H) is described. In the SiOC(-H) film, the CH3 group as an end group is introduced into the -O-Si-O- network, thereby reducing the density to decrease the dielectric constant. X-ray photoelectron spectroscopic (XPS) studies were carried out to study the binding energies of Si-C, O-Si-O, C-C(H), C=C, C-O and C=O bonds in the SiOC(-H) films as functions of the flow rate ratio. The dielectric constant of the SiOC(-H) film was evaluated by using the C-V measurements for a metal-insulator-semiconductor (MIS), Al/SiOC(-H)/p-Si(100), structure.