CRYSTALLOGRAPHIC TEXTURE OF C54 TITANIUM DISILICIDE AS A FUNCTION OF DEEP-SUBMICRON STRUCTURE GEOMETRY

Detailed analysis of the crystallographic texture of C54 TiSi2 was per formed and showed a strong correlation between the geometry of the sil icide structures and preferential crystallographic orientation. The st udy was undertaken an blanket and patterned TiSi2 films formed in the reaction between 32 nm of Ti and undoped polycrystalline silicon using both in situ x-ray diffraction during heating and post-anneal four-ci rcle pole figure reflection geometry measurements, Full pole figures w ere taken to determine the distribution of C54 TiSi2 grain orientation s in narrow (0.2 to 1.1 mu m) lines which was compared with similar re sults obtained from unpatterned (blanket) films. While in blanket film s we found the presence of weak <311> C54 TiSi2 crystallographic orien tation perpendicular to the sample surface, the <040> preferential ori entation dominated in patterned submicron line structures and increase d with decreasing linewidth. Using pole figure analysis, we observed s trong <040> fiber texture in narrow lines with a slight variation in t he tilt of the (040) planes normal in the direction perpendicular to t he line (full width at half maximum [FWHM] approximate to 6 degrees), but very little along the length of the line (FWHM approximate to 2 de grees). In addition, a preferred in-plane (azimuthal) orientation of < 040> crystals was found which showed that most of the <040> grains bad their (004) plane normals oriented parallel with the line direction, These findings support a model of the C49 to C54 TiSi2 transformation involving rapid growth of certain orientations favored by the one-dime nsional geometry imposed by narrow lines.