Temperature effects on electrical resistivity of selected ceramics for high‐temperature packaging applications

Abstract

We report the results of the characterization of the electrical resistivity of selected ceramic materials, namely aluminum nitride (AlN), silicon nitride (Si₃N₄), beryllium oxide (BeO), yttrium oxide (Y₂O₃), and non‐ceramic silicon dioxide (SiO2), which are candidates for packaging silicon carbide (SiC) sensors and electronics that can operate at temperatures beyond 800°C. Samples of these materials were thermally cycled twice to 1200°C in nitrogen while the bulk and surface resistivities were measured in situ. Although the resistivity values of all samples dropped with increasing temperature, BeO maintained the relatively highest bulk and surface resistivity values at 1200°C of 28 and 34 kΩ cm, respectively, while AlN had the lowest values at 6.8 and 0.64 kΩ cm. In terms of viability for packaging SiC sensors for >800°C operation, AlN and Si₃N₄ are the choice candidates due to their lowest mismatches in the coefficient of thermal expansion with SiC. However, the relative resistivity stability of Si₃N₄ over AlN makes it a promising candidate, even with its lower thermal conductivity relative to AlN.