Papers by Keyword: Polycrystalline Thin Films

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Authors: H. Toraya, H. Hibino, Takashi Ida
Abstract: A quantitative basis for rocking curve measurements of preferentially oriented polycrystalline thin films is presented. The Gaussian function is used for modeling the preferred orientation of crystallites around the plane normal of the specimen surface. A theoretical rocking curve is fitted to the observed curve by the least-squares method, and the degree of preferred orientation, given in volume fraction, can be derived from a refined preferred orientation parameter of the distribution function even when the preferred orientation is very small. Uses of diffractometers equipped with parallel-beam optics and the integrated intensity rather than peak intensity are important for reliable rocking curve measurement.
Authors: Li Sha Niu, Ting Ting Dai
Abstract: A 2-D Finite element simulation method was developed based on the kinetic law and the energy evolution during the whole process of deformation, which is used to investigate the creep size effects in polycrystalline thin metal film on substrates. Three diffusion paths (e.g. surface, grain boundary and lattice diffusion) are considered in the present model. The diffusion rate for these three processes was compared under different loading conditions with corresponding microstructure. It’s found that grain boundary diffusion is coupled with another diffusion channel. Creep size effects result from mass transferring in thin film. The model gave the quantitative results of the influences of the film thickness, grain size, and the constraints of the substrate on polycrystalline metal film diffusion. The simulated results present the evolution of the point defects in grain interior, the strain and stress field. The distribution of the crack-like stress in the grain boundary could explain the stress concentration mechanisms clearly and this also agrees with the literature results.
Authors: Romain Cauchois, András Borbély, Patrice Gergaud, Mohamed Saadaoui, Karim Inal
Abstract: Colloidal suspensions of nanoparticles are increasingly employed in the fabrication process of electronic devices using inkjet-printing technology and a consecutive thermal treatment. The evolution of internal stresses during the conversion of silver nanoparticle-based ink into a metallic thin-film by a thermal sintering process has been investigated by in-situ XRD using the sin2ψ method. Despite the CTE mismatch at the film/substrate interface, the residual stress in silver films (below 70 MPa) remains lower than in conventional PVD thin-films, as a result of the remaining porosity. A Warren-Averbach analysis further showed that the crystallite growth is associated with a minimization of the twin fault density and the elastic microstrain energy above 150°C. A stabilization of the microstructure and internal stress is observed above 300°C. Inkjet-printing technology thus appears as a good alternative to conventional metallization techniques and offers significant opportunities asset for interconnect and electronic packaging.
Authors: M.S. Jani, H.S. Patel, J.R. Rathod, K.D. Patel, V.M. Pathak, R. Srivastava
Abstract: In this paper structural and optical properties of CdSe thin films with different thickness deposited by thermal evaporation under vacuum onto glass substrates are presented. The structural investigations performed by means of XRD technique showed that the films have a polycrystalline and hexagonal (würtzite) structure. The values of some important parameters of the studied films (absorption coefficient and optical bandgap energy) are determined from transmission spectra. The values of the optical bandgap energy (Eg) calculated from the absorption spectra, ranged between 1.67 - 1.74 eV.
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