Ternary Ta-Si-N films for sensors and actuators

Ta-Si-N films having thicknesses up to several micrometres are investigated in view of their use in sensors and actuators. The films are deposited by reactive sputtering in an Ar/N-2 plasma employing a Ta3Si3 target. In addition to their significant electrical characteristics, these ternary film materials also exhibit excellent mechanical properties. On X-ray-amorphous layers a surface roughness of less than 2 nm has been measured. A crystallization temperature exceeding 800 degrees C has been observed by X-ray diffraction analysis. Using Al as a sacrificial layer, the fabrication of freestanding Ta-Si-N surface microstructures is demonstrated, and their application in microelectromechanical transducers is discussed.