Showing papers by "Akira Kinbara published in 1991"

Structure modification of radio frequency sputtered LaB6 thin films by internal stress

Abstract: Thin films of LaB6 are prepared by a radio frequency (rf) magnetron sputtering technique. The effect of sputtering conditions on the film properties of internal stress and crystalline orientation are investigated. The film deposited at low pressures (<1 Pa) has a strong compressive stress as high as 109 Pa. As the pressure of Ar discharge gas decreases, the internal stress becomes greater and the preferred orientation is transformed in the sequence: (100)→(110)→(111). This behavior can be explained as an energetically favorable structure of LaB6 film by taking both the surface energy and the strain energy into account. An application of a negative bias (−20 V) to substrates results in a greater stress, so that the (110) and (111) orientation becomes more preferential.

Island structure of sputter-deposited Ag thin films

Abstract: Silver was sputter-deposited on carbon membranes in an rf magnetron apparatus. The island structure of the Ag films of a few nanometres thick was studied in a transmission electron microscope. Distribution of the island size and the inter-island distance was measured to elucidate the effect of the substrate bias. A grounded grid was placed to shield the substrates electrostatically so that the applied bias did not affect the plasma. The structure of Ag films evaporated in a high vacuum was also examined as a reference. While islands grew to coalesce followed by the generation of secondary islands in vacuum-deposited films, islands of sputter-deposited films showed a tendency to grow in a deformed shape and form a network structure. When a negative bias was applied to the substrate during the sputtering the island shape was modified to become rounder and the arrangement became more uniform. Islands of almost the same size that were separated equally from each other grew at negative bias voltages greater than −50 V, where the energy deposition was 300 eV per Ag atom.