Piezoresistivity in ruthenium-based metal–insulator– metal structures

Abstract

The resistance change with applied stress was measured for ruthenium-based metal–insulator–metal thick films under tensile and hydrostatic pressures over the temperature range −25 to +135 °C. The derived longitudinal, transverse, and hydrostatic piezoresistivity coefficients were corrected for elastic effects to yield the corresponding piezoresistivity coefficients and their temperature dependencies. The results clearly demonstrate for the first time a hydrostatic piezoresistivity coefficient that is sevenfold larger than the longitudinal component. Symmetry analysis is used to explain this phenomenon and to deduce additional piezoresistivity matrix elements and their degeneracy. In addition, pressure effects on electrical transport support a tunneling mechanism.