| 초록 |
In present study, nanoporous organosilicate low-k thin films were prepared using covalently bonded porogen to silsesquioxane matrix, where adamantane group was used as porogen. Comonomers containing grafted porogen were polymerized with methyltrimethoxysilane (MTMS). Terpolymer was also synthesized by addition of 1,2-bis(trimethoxysilyl)ethane (BTMSE) for advanced mechanical strength. Porogen decomposes above 300 oC after matrix vitrification, which is shown by TGA and FT-IR spectra, and consequently refractive indices and dielectric constants are lowered by the formation of nanopores. The porosity was calculated from refractive index with Lorentz-Lorenz equation and dielectric constants were measured by metal-insulator-metal (MIM) method. The mechanical properties of low dielectric films were also compared, which is obtained from nanoindentation. Ter-polymerization with BTMSE increases mechanical properties due to the formation of high crosslinking density since the cage-like structure formed by the bulky graft porogen is suppressed. |
