In order to meet the requirements of faster speed and higher packing density for devices in the field ofsemiconductor manufacturing, the development of Cu/Low k device material is explored for use in multi-layer interconnection.SiOC(-H) thin films containing alkylgroup are considered the most promising among all the other low k candidate materialsfor Cu interconnection, which materials are intended to replace conventional Al wiring. Their promising character is due to theirthermal and mechanical properties, which are superior to those of organic materials such as porous SiO2, SiOF, polyimides,and poly (arylene ether). SiOC(-H) thin films containing alkylgroup are generally prepared by PECVD method usingtrimethoxysilane as precursor. Nano voids in the film originating from the sterichindrance of alkylgroup lower the dielectricconstant of the film. In this study, methyltriphenylsilane containing bulky substitute was prepared and characterized by usingNMR, single-crystal X-ray, GC-MS, GPC, FT-IR and TGA analyses. Solid-state NMR is utilized to investigate the insolublesamples and the chemical shift of 29Si. X-ray single crystal results confirm that methyltriphenylsilane is composed of one Simolecule, three phenyl rings and one methyl molecule. When methyltriphenylsilane decomposes, it produces radicals such asphenyl, diphenyl, phenylsilane, diphenylsilane, triphenylsilane, etc. From the analytical data, methyltriphenylsilane was found tobe very efficient as a CVD or PECVD precursor.