Abstract: Tetrahedral amorphous carbon （ta-C） thin films are promising to be the buried insulator for Silicon-On-Insulator （SOI） in high-power and high-temperature integrated circuits. Ta-C thin films were prepared by using filtered arc deposition （FAD） system. The surface morphology, microstructure and electronic characteristics of the ta-C thin films were studied through AFM, non-RBS, IR and I-V measurements. The ta-C films have high content of sp³-bonds of carbon （87%）, display outstanding surface topography （low surface roughness with the R_ms value under 0.5 nm）, and own excellent electrical property （breakdown field of 4.7 MV/cm）.