Thermal conductivity measurements of low-k films using thermoreflectance phenomenon

The thermal conductivity of low-dielectric-constant (low-k) materials has been studied by a nano second thermoreflectance measurement system (Nano-TheMS). The Nano-TheMS, which utilizes thermoreflectance, can easily measure the thermal conductivity of thin film of nano-meter scale thickness. We have measured a series of low-k film samples with varying methyl group content. The methyl group content is a significant factor in determining the dielectric constant and mechanical strength of low-k materials. We have also measured the temperature dependence of the thermal conductivity from room temperature to 300 °C as this dependence is essential to simulate realistic temperature distributions inside integrated devices. It was found that its dependence is not remarkable but the thermal conductivity gradually increase with rising temperature.