Ces dernières années la miniaturisation des microsystèmes atteint la limite physique de leur développement. Ainsi une de voie d’innovation dans l’industrie des semiconducteurs est l’intégration des fonctionnalités supplémentaires au sein des composants déjà existants.Le projet consiste à intégrer, dans une même couche métallique d’interconnexion CMOS, un MEMS capable, par sa rotation, d’établir un contact électrique.Les verrous se situent dans la libération des parties mobiles par dissolution de l’oxyde environnant (déformation hors plan sous l’effet des contraintes résiduelles, stiction, présence de résidus qui empêchent le contact), dans l’actionnement (densité de courant, répétabilité, durabilité, fiabilité) ainsi que, la capacité d’établir un vrai contact électrique à faible résistance (aire réelle / apparente du contact des surfaces rugueuses, pollution du contact).Le travail réalisé a porté sur la conception, le design et la simulation des microsystèmes afin de surmonter ces difficultés et / ou d’étudier le comportement et mesurer les effets. / In recent years the miniaturization of microsystems is reaching the physical limit of its development. Thus, a path of innovation in the semiconductor industry is additional functionalities in existing components.The project consists to integrate a MEMS, within the same metal interconnect of CMOS layer which, by rotating, can establish an electrical contact.The obstacles are in the release of the moving parts by dissolution of the surrounding oxide (out of plane deformation under the effect of residual stress, stiction, residues which prevent contact), in the actuation (current density repeatability, durability, reliability) and, for ohmic switches, the ability to establish a real electrical contact with low resistance (real / apparent area of contact with rough surfaces, contact pollution).The work carried out has focused on conception (design) and simulation of microsystems to overcome these difficulties and / or to study the behavior and measure the effects.

Cette thèse porte sur le thème général de la fiabilité des circuits microélectroniques. Le but de notre travail fut de développer un outil de simulation multi-physiques pour la conception des circuits intégrés fiables qui possède les caractéristiques innovatrices suivantes : • (i) L’intégration dans un environnement de conception microélectronique standard, tel que l’environnement Cadence® ; • (ii) La possibilité de simulation, sur de longues durées, du comportement des circuits CMOS analogiques en tenant compte du phénomène de vieillissement ; • (iii) La simulation de plusieurs physiques (électrique-thermique-mécanique) couplées dans ce même environnement de CAO en utilisant la méthode de simulation directe. Ce travail de thèse a été réalisé en passant par trois grandes étapes traduites par les trois parties de ce manuscrit. / This thesis was carried out under the theme of the microelectronics Integrated Circuits Reliability. The aim of our work was to develop a multi-physics simulation tool for the design of reliable integrated circuits. This tool has the following innovative features : • (i) The integration in a standard microelectronics design environment, such as the Cadence® environment ;• (ii) The possibility of efficient simulation, over long periods, of analog CMOS circuits taking into account the aging henomenon ; • (iii) The simulation of multiple physical behaviours of ICs (electrical-thermalmechanical) coupled in the same environment using the direct simulation method. This work was carried out through three main stages detailed in the three parts of this Manuscript.

This report formulates the boundary conditions and discretization method for conducting a simulation of heat with liquids and solids through the finite element method. It introduces the reader to the movement that is due today with optimization of heat transport and mitigation generally described as the fourth generation of district heating. It presents the scope: calculating the heat release from pipes in hydronic underfloor heating, and presents the belonging question: how does heat release from different heating pipe patterns affect the body’s heat transfer? Simulation of the work is conducted with the delimitations of using a single boundary slip condition addressing friction and only using water as pipe flow medium. It focuses on the pattern’s ability to affect the heat to the body, of which characteristically manifests a square concrete slab in the running simulations. By using different cases, it analyses how patterns using the same length of pipes emit their average heat to the covering top surface differently, both as the heating level alternates, and duration for response changes. This meanwhile they are affected by analog boundary temperature conditions.    A sensitivity analysis is done answering how the various patterns tested are affected by change of propagation speed for the flowing medium, showing that a spiral formed pattern with evenly spread piping is the least affected. The results show that the pattern with alternating pipe spacing gives the best average heat emission in the simulated cases. It also concludes that minor changes in the pattern area will have profound effect on the average transferred heat from the body’s top surface.