Microstructure modification of silver films deposited by ionized magnetron sputter deposition

Silver films have been deposited under controlled ion bombardment by ionized magnetron sputter deposition (IMSD). The technique uses a built-in rf coil to generate an inductively coupled plasma confined close to the substrate. This enables precise control of both the bombarding ion flux(by rf power) and the energy (by substrate bias). By varying the flux and energy of bombarding ions, the film's structure and properties can be easily modified. Crystallography, grain size, and film texture have been characterized using the x-ray diffraction method, and film stress was measured by a substrate curvature technique. A focused ion beam was used to section the deposited films and to observe the surface morphology and cross-sectional structure. The electrical resistivity ratio (room to liquid nitrogen temperature: R-298 (K)/R-77 K) was used to investigate the influence of the film structure on the conductivity. The persistence of bombardment induced film property variation with thickness was studied in terms of the texture variation in bilayers consisting of IMSD and magnetron sputtering deposited films. It is found that the microstructure of deposited films depends predominantly on the ion bombardment during the initial stages of film growth. Using the IMSD technique, the structure and related properties of silver films have been modified by depositing films under precisely controlled ion bombardment. (C) 1999 American Vacuum Society. [S0734-2101(99)02405-7].