Studies on the low dielectric SiOC(–H) thin films deposited using MTMS and oxygen as precursors by UV source assisted PECVD

Low-k SiOC(–H) films were deposited on a p-type Si(100) substrate using ultraviolet (UV) source assisted plasma-enhanced chemical vapor deposition with a mixture of a methyltrimethoxysilane [MTMS: CH3Si(OCH3)3] and oxygen gases. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to investigate the bonding configurations and the atomic concentrations of the SiOC(–H) films. The lowest dielectric constant was about 2.3 ± 0.11, which was deposited using the [MTMS/(MTMS + O2)] mixture gases of 100% with UV irradiation. The SiOC(–H) film with low dielectric constant have cross-linking structure with nano-pore due to the combined Si–CHn–Si bond and Si–O–Si network, in which the Si–CHn–Si bond is formed due to the incorporation of CH3 groups into the Si–O–Si network.