Ultraviolet irradiation effect on the properties of leakage current and dielectric breakdown of low-dielectric-constant SiOC( H) films using comb capacitor structure

Low-dielectric constant SiOC( H) films were deposited on p-type Si(100) substrates by plasma-enhanced chemical-vapor deposition (PECVD) using dimethyldimethoxy silane (DMDMS, C 4H 12O 2Si) and oxygen gas as precursors. To improve the physicochemical properties of the SiOC( H) films, the deposited SiOC( H) films were exposed to ultraviolet (UV) irradiation in a vacuum. The bonding structure of the SiOC( H) films was investigated by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The electrical characterization of SiOC( H) films were carried out through I–V measurements using the comb-like patterns of the TiN/Al/Ti/SiOC( H)/TiN/Al/Ti metal–insulator–metal (MIM) structure. Excessive UV treatment adversely affected the SiOC( H) film, which resulted in an increased dielectric constant. Our results provide insight into the UV irradiation of low- k SiOC( H) films.