Evolution of microstructure and residual stress in sputtered chromium and chromium(x) nitrogen(y) thin films

This dissertation examines several fundamental aspects of sputtered films, including chemistry, structure, texture, residual stress and growth morphology. The systems considered are Cr films, CxNy films and Ta films.; In the first system, the studies focus on some of the unique microstructural features of Cr films. These films develop well-organized anisotropic microstructures and in-plane texture. A texture turnover with thickness has been revealed. The out-of-plane preferred orientation changes from [110] to [111], and conformally, the in-plane preferred orientations vary as well. A new methodology has been developed, in which an anisotropic in-plane stress distribution in a thin film can be determined. This approach has been applied to the Cr films. The anisotropic stresses in these films are related to the evolution of anisotropic microstructure and in-plane texture.; The studies of reactively sputtered CrxNy thin films concentrate on phase formation, microstructure, texture, residual stress and growth morphology. It has been shown that these characteristics are predominantly affected by nitrogen flows. The phases identified in the films include Cr, hexagonal Cr2N, and cubic CrxNy, depending on deposition conditions. The composition of the cubic phase exhibits a wide homogeneity span as indicated by large variations of its lattice parameter. At certain nitrogen flow, a nano-crystalline, N-deficient CrxN y film can be obtained. The CrxNy films deposited at high nitrogen flows develop both out-of-plane texture and in-plane texture. In these films, the elongated grains align crystallographically, forming well-defined microstructures.; A new experimental apparatus, which utilizes white beam transmission Laue topography and concomitant radiography, has been developed and applied to study cracking/delamination of thin films. Using the systems, the sputtered Ta and CrN films have been studied, and their failures are related to different types of stress development, respectively. This work has demonstrated for the first time that in situ observation via x-ray topography/radiography is a useful means for observing stress induced film failures of different modes in a real time fashion.