Axiotaxy : Off-normal fiber-like Texture in Thin Films on Single Crystalline Substrates

Synchrotron radiation was used to measure pole figures of orthorhombic NiSi, tetragonal a-FeSi2 and cubic CoSi2 films on Si(100) substrates and orthorhombic NiGe on a Ge(100) substrate. Complex, though symmetrical patterns of lines were observed on the pole figures. The texture could not be categorized within the standard classification of random, fiber and in-plane texture for thin films. The lines on the pole figures are created by a fiber-like texture, with the fiber axis normal to Si(110)-type planes (i.e. at 45 =from the surface normal). It is expected that any thin film that is formed on a single-crystalline substrate and for which a low-index crystallographic plane exists with the same interplanar spacing as a low-index plane in the substrate, will exhibit this new type of texture.