Sensor head for measurement of stress anisotropy in thin films

Abstract

Mechanical stresses in thin films are measured most often by the bending beam or bending plate method. To determine the stress anisotropy, the complete deformation of a thin plate has to be analysed in two dimensions. A sensor head has been developed which monitors the detailed shape electrically by an array of capacitor probes. The sensor head is suitable for stress measurements in situ during film deposition and at elevated temperatures. The operation is demonstrated by Ni films where anisotropic stresses are introduced by magnetostriction.