Process-dependent thermal transport properties of silicon-dioxide films deposited using low-pressure chemical vapor deposition

The volumetric heat capacity and thermal conductivity of silicon-dioxide fi lms prepared using low-pressure chemical vapor deposition (LPCVD) are measu red. The measurements employ the 3 omega technique, which is extended to de termine the thermal conductivity anisotropy and volumetric heat capacity of thin dielectric films. The thermal conductivity of the silicon-dioxide fil ms exhibits a significant process dependence, which cannot be attributed to highly oriented microvoids or impurities. The volumetric heat capacity, in contrast, is largely independent of processing history provided that appro priate corrections are made to account for porosity and impurity contributi ons. This study provides evidence that process-dependent structural disorde r strongly influences the thermal conductivity of amorphous films. (C) 1999 American Institute of Physics. [S0021-8979(99)01110-X].