Interface Characterization and Current Conduction in Low-Dielectric-Constant SiOC(-H) Films with a MIS Structure

摘要

We report on the electrical conduction of as-deposited and annealed SiOC(-H) films deposited by using plasma enhanced chemical vapor deposition (PECVD). The leakage current density was reduced to a low value of 3.02 x 10~( -8) A/cm~2f or the film anealed at 40 °C. Both Schotky and Poole-Frenkel emissions were observed to occur in all SiOC(-H) films deposited at different flow rate ratios. However, both emissions were found to be more dominant with increasing flow rate ratio, which may be due to the lower surface state density with increasing flow rate ratio. Furthermore, annealing of the SiOC(-H) film significantly enhanced the electrical properties. The leakage current density was reduced by about one order and the breakdown strength was increased from 1.61 for the as-deposited sample and to 2.81 MV/cm for sample annealed at 400 °C for a flow rate ratio of 90 %. The value of the dielectric constant calculated from the I-V plots was consistent with that calculated from the C-V measurements.