Thermal conductivity and interfacial thermal resistance of polymeric low k films

The effective thermal conductivity of four polymeric thin films with distinct molecular morphologies has been measured as a function of film thickness down to 70 Å using a 3ω technique. Comparing to SiO2, the intrinsic thermal conductivity of polymers is about 5–10 times smaller while the interfacial thermal resistance is about 2–10 times larger. The interfacial thermal resistances are explained in terms of the mismatches of acoustic and mechanical properties between polymers and crystalline materials. Both elastic and inelastic scatterings at the interface are examined.