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International audience; The multivectorial algebras present yet both an academic and a technological interest. Difficulties can occur for their use. Indeed, in all applications care is taken to distinguish between polar and axial vectors and between scalars and pseudo scalars. Then a total of eight elements are often considered even if they are not given the correct name of multivectors. Eventually because of their simplicity, only the vectorial algebra or the quaternions algebra are explicitly used for physical applications. Nevertheless, it should be more convenient to use directly more complex algebras in order to have a wider range of application. The aim of this paper is to inquire into one particular Clifford algebra which could solve this problem. The present study is both didactic concerning its construction and pragmatic because of the introduced applications. The construction method is not an original one. But this latter allows to build up the associated real algebra as well as a peculiar formalism that enables a formal analogy with the classical vectorial algebra. Finally several fields of the theoretical physics will be described thanks to this algebra, as well as a more applied case in general relativity emphasizing simultaneously its relative validity in this particular domain and the easiness of modeling some physical problems.

International audience; This work deals with a methodology to evaluate residual stresses within microelectronic devices by using MOS (Metal Oxide Semiconductor) rosette stress sensors. The stress tensor was evaluated by carrying out electrical measurements on test vehicle: the bridge from electrical to stress values was ensured by the piezoresistive relations and, prior to further in-house calibration, coefficients from literature were employed. For correlation purpose, numerical simulations were performed in order to evaluate stresses induced by TSV (Through Silicon Via). In this paper, the whole framework is described, and stress fields evaluated from in-situ electrical measurements on CMOS65 rosette sensor are compared to simulated ones. Some of the ultimate targets of this work are to develop a validated framework to deeply understand TSV induced thermo-mechanical stresses and to allow design rules definitions for products reliability and transistor performances.

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. Inkjetprinting technology thus appears as a good alternative to conventional metallization techniques and offers significant opportunities asset for interconnect and electronic packaging. cop. (2014) Trans Tech Publications, Switzerland. 'Conseil General de l'Aube'; Conseil National de la Recherche Scientifique (CNRS); et al; Grand Troyes; Proto Manufacturing; Region Champagne-Ardenne