Thermal characterization of vertically-oriented carbon nanotubes on silicon

An exploratory thermal interface structure, made of vertically oriented carbon nanotubes directly grown on a silicon substrate, has been thermally characterized using a 3-omega method. The effective thermal conductivities of the CNT sample, including the effects of voids, are found to be 74 W/m·K to 83 W/m·K in the temperature range of 295K to 323K, one order higher than that of the best thermal greases or phase change materials. This suggests that the vertically oriented CNT potentially can be a promising next-generation thermal interface solution. However, fairly large thermal resistances were observed at the interfaces between the CNT samples and the experimental contact. Minimizing these contact resistances is critical for the application of these materials.