Growth textures of thick sputtered films and multilayers assessed via synchrotron transmission Laue

Abstract

The growth textures of thick sputtered Mo metallizations and Mo/W multilayers, were characterized via a synchrotron white‐beam (WB) x‐ray transmission Laue technique. Transmission x‐ray diffraction studies of Mo specimens up to 61 μm thick were performed with WB synchrotron radiation; while the practical thickness limit for similar observations using a conventional laboratory Cu K(α) x‐ray source is ten times smaller. This unique approach used polychromatic x rays to simultaneously produce diffraction from a wide spread of orientations of many crystallographic planes for all the grains within a relatively large specimen volume (≊60×106 μm3). These patterns were obtained for polycrystalline 31‐ and 61‐μm‐thick Mo/W multilayer specimens, and a 35‐μm‐thick‐monolithic Mo foil specimen. In all three cases the alignment of specimen grains was similar to what would be expected for single‐crystal transmission patterns, except that the recorded intensity distributed was less localized. The WB transmission images were indexed using a reciprocal space construction for the Laue case. In the multilayers, the grains were oriented out‐of‐plane such that 〈110〉 crystallographic planes were aligned in the direction of sputter growth, while in the monolithic Mo specimen 〈111〉 crystallographic planes were so aligned, i.e., perpendicular to the deposition substrate. A spread in orientation of ∼5° was measured in the multilayer specimens, while the monolithic Mo specimen showed a spread of ∼30° when compared to a perfect single‐crystal orientation. Preferred orientation was also observed within the plane of growth to varying degrees for all three samples. © 1995 American Institute of Physics.