Impact of experimental timescale and geometry on thin-film thermal property measurements

Integrated circuits require effective removal of increasing heat fluxes fro m active regions. Thermal conduction strongly influences the performance of micromachined devices including thermal actuators, Peltier-effect coolers. and bolometers. The simulation of these devices requires thermal property data for the thin-film materials from which they are made. While there are many; measurement techniques available, it is often difficult to identify t he most appropriate tol a device. This article reviews thin-film thermal ch aracterization methods with an emphasis on identifying the properties extra cted by the techniques. The characteristic timescale of heating and the geo metry of the experimental structure govern the sensitivity of the data to t he in-plane and out-of-plane conductivities, the volumetric hat capacity, a nd the interface resistances of the film. Measurement timescales and geomet ry also dictate the material volume probed most sensitively within the film . This article uses closed-form and numerical modeling to classify techniqu es according to the properties they measure. Examples of reliably: extracte d properties are provided for some experimental configurations, This articl e simplifies the process of choosing the best characterization technique fo r a given application in microdevice thermal design.