Thermal Conductivity of Thin Silicon Dioxide Films in Integrated Circuits

Thermal conductivities of thin silicon dioxide films are measured using specialized test structures with parallel plate-electrodes. Films with thicknesses in the range of 0.6 ¿m to 2.5 ¿m are investigated. For the first time it is experimentally verified that the temperature dependence of the thermal conductivity of thin silicon dioxide films follows that of bulk fused quartz. Measured conductivities are only 20 % to 30 % below the one of bulk fused quartz. The impact of thermal resistances at boundaries between silicon dioxide and metallization is shown to be insignificant for the films investigated.