International audienceA mathematical model of a Li/LiPON (Lithium Phosphorus Oxynitride)/LiCoO2 all-solid-state thin-film microbattery was developed. It is isothermal, one-dimensional and takes into account lithium diffusion and electron migration in the positive electrode, migration of lithium ions in the solid electrolyte, and charge-transfer kinetics at the electrode/electrolyte interfaces. Model input parameters are determined for the case of a reference microbattery available on the market using a variety of electrochemical techniques such as galvanostatic intermittent titration technique and electrochemical impedance spectroscopy. A good agreement is found between simulation and charge/discharge experimental data, both in galvanostatic and potentiostatic operation, which therefore validates the model. Finally, the temperature dependence of input parameters is introduced into the model, which allows for predicting microbattery operation at different temperatures

Low-temperature epitaxial growth of Si and Si1−xGex (referred to as SiGe, hereafter) has been obtained using an industrial, 200 mm, single wafer chemical vapor deposition module operating at reduced pressure. Epitaxial Si and heteroepitaxial SiGe deposition with Ge content ⩽30% have been studied for buried channel applications in (PMOSFET) devices or as base for heterojunction bipolar transistors (HBTs). The dependence of Si and SiGe deposition rates on filling ratio and exposed windows and their evolution with the addition of HCl to the gas mixture are investigated. In contrast to selective Si growth where the global loading effect decreases slowly with temperature, the growth rate of SiGe at low temperature is strongly dependent on the oxide coverage. The addition of HCl into the gas mixture allows minimizing the dependence of the SiGe growth rate on both oxide coverage and window size. The effect of the addition of HCl on Ge and dopants incorporation is investigated on bare and/or device wafers. Results on facet formation and orientations are also presented for selective Si and SiGe growths. Finally, we report basic electrical results on selective Si epitaxial and SiGe heteroepitaxial structures, which have been integrated in PMOSFET and HBT devices.

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