Structure-Modification Model of Porogen-Based Porous SiOC Film with Ultraviolet Curing

The effect of ultraviolet (UV) curing on film properties of porogen based porous SiOC (P-SiOC) film was investigated. The P-SiOC films were prepared by plasma-enhanced chemical vapor deposition (PECVD) using alkoxysilane and porogen (hydrocarbon). UV curing time was changed from 0 s to 1000 s. The variation of the k value and elastic modulus on the P-SiOC film with UV curing can be classified into three phases. From the behavior of pore density and free volume rate evaluated by using positron annihilation spectroscopy (PAS), the multiphase model for structural modification of P-SiOC film by UV curing was proposed. In addition, the optimum UV curing time for obtaining a superior P-SiOC film with lower k value and higher mechanical strength was determined.