EFFECT OF THERMAL-TREATMENT ON THE MECHANICAL AND STRUCTURAL-PROPERTIES OF GOLD THIN-FILMS

Low-stress (< 50 MPa) gold films 0.7- and 2-mu-m thick were deposited by electroplating from a cyanide solution at 40-degrees-C at a current density of 2.5 mA/cm2. Thin gold films under higher stress were electron-beam evaporated at room temperature or sputtered at a power of 150 W under 2-Pa argon gas. The stress dependence of these films on the post-deposition annealing temperature up to 200-degrees-C was investigated, using an interferometric method at room temperature. The stress evolution is discussed in relationship to the thermally induced changes in the structure and the microstructure of the various films investigated by transmission electron microscopy.