Improvements of on-membrane method for thin-film thermal conductivity and emissivity measurements

In this paper we present a numerical simulation and various test-structure configurations, which enable the measurement of the thermal conductivity and emissivity of thin films by the Volklein method to be more versatile and accurate. The capabilities of the Volklein method to measure a broader range of materials are extended by using smaller membranes and by taking into account the two-dimensional heat transfer in the membrane. The measurement method is extended to the measurement of the heat transfer coefficient of convection. The test-structures are adapted to be integrated in the process flow of a thin-film-based thermoelectric micro-generator by putting the thermoelectric material to be measured on the top of the membrane and side by side with the heater. The measurement method is tested on various materials ranging from ceramics and metal to polycrystalline silicon.