Theoretical consideration of the parameter space for thermal conductivity measurements of thin diamond films

Thin diamond films have important technological applications in microelectronics. The advent of new methods of synthesis and a wide variety of growth morphologies require effective characterization of their thermal properties. The theoretical basis for the measurement of thin film thermal conductivity is discussed. Temperature distributions in the case of steady state and transient methods of thermal conductivity measurement are enumerated with a view to providing a quantitative basis for thermal property measurements of diamond thin films. The effect of three different substrate materials viz., glass, Si and SiC on the thermal conductivity measurement are numerically evaluated. It is shown that the presence of a substrate material does significantly alter the calculated temperature profiles, thereby indicating that a careful consideration of the experimental implementation is imperative for effective extraction of the thermophysical data. A brief discussion on thermal conductivity anisotropy is also included.