Structural and electrical changes during the heat treatment of Au-SiO x cermet films

Abstract

Au-SiO x cermet films with different gold contents (20–80%) have been produced by vacuum deposition at substrate temperatures between 25° and 400°C. The changes in structure and electrical properties which take place during heat treatment have been studied by electron diffraction and stereo electron microscopy. In situ electron microscopy allows the simultaneous observation of structural reordering and variations in the electrical resistivity of the film. The coagulation of gold caused by the reordering processes during the heat treatment is affected by the deposition conditions. The distribution of the gold islands in the thickness of the film has been investigated by stereo electron microscopy. Relations between the morphology and the electrical properties—sheet resistance, temperature coefficient and frequency dependence of the resistance—of the cermet films were obtained.