Characteristics of organic–inorganic hybrid plasma polymer thin films for low- κ ILD applications

Abstract

This study investigated the effects of plasma power and tetraethylorthosilane (TEOS) to cyclohexene ratios on low- κ organic–inorganic hybrid plasma polymer thin films deposited on silicon (100) substrates. These films were deposited using a plasma enhanced chemical vapor deposition (PECVD) method, in addition to the electrical and mechanical properties of the resulting composites. Cyclohexene and TEOS were used as organic and inorganic precursors, respectively, with hydrogen and argon as precursor bubbler gases. Furthermore, additional argon was used as a carrier gas. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The ellipsometry results showed the thickness of the hybrid thin film, and the FT-IR spectra showed that the hybrid polymer thin films were completely fragmented and polymerized between cyclohexene and TEOS. AFM results showed that polymer films with a smooth surface could be grown under various deposition conditions, while TEM and XRD showed that the hybrid thin film was an amorphous plasma polymer thin film without porosity. In addition, current–voltage ( C– V) curves were prepared to calculate the dielectric constants. Post-annealing was applied to investigate the thermal stability of hybrid plasma polymer thin films in the hardness, Young's modulus, thermal shrinkage, and the dielectric constant at 400 °C.