Determining the thin-film thermal conductivity of low temperature PECVD silicon nitride

The design and optimization of micromachined thermal sensors often requires information on accurate material properties of the used thin-films. These data can differ considerably from those stated for bulk matter and are strongly process-dependent. In this contribution a micromachined canitlever structure is proposed, which allows to directly determine the thermal conductivity of dielectric thin-films from a single steady-state measurement without the need of a complex mathematical model. For low temperature PECVD nitride a thermal conductivity of 1.18 W/mK was obtained, which is below the literature values reported for standard thin-film silicon nitride.