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Solid state refrigeration is of great interest due to its potential application in electronic and optoelectronic systems. Nowadays, macroscopic thermoelectric coolers are part of such systems and their cooling performance and reliability are well proven. However, the feasibility of microstructuring such kind of devices by means of photolithographic techniques, opens the possibility of integration on a chip for better local thermal management. Together with previous facts, electrodeposition processes are well known to be low cost, highly scalable and compatible with lithographic techniques. In this work we report on the fabrication of BiTe-based Micro-Thermoelectric Coolers by means of a mixed process flow involving photolithography and electrodeposition techniques. Materials and geometry of the device have been chosen to optimise the cooling performance on an integrated photonic system.

The control of magnetic properties by an electric field is exciting both from the point of view of applications and fundamental research. Low-power electrical switching of magnetic properties is e.g. discussed as promising alternative to temperature control as in heat assisted magnetic recording. Magnetoelectric coupling is known for one- or two-phase multiferroic materials and magnetic semiconductors but is, in these cases, restricted to low temperatures or a fixed substrate. More and more studies report on an influence of electric field on the magnetism also of nanostructured metals [1-6]. The advantage here is that an effect can be exploited at room temperature and may be very large due to the strong ferromagnetism. The electric field can be applied either by using solid dielectric layers or by liquid electrolytes. Many magnetic properties as e.g. coercivity, saturation magnetization, anisotropy and Curie temperature have been shown to be electric field dependent and large effects have been achieved already. Materials studied include Fe, Co, FePt, FePt, CoPt ultrathin films or nanoporous structures. In almost all cases, however, the simple picture of an increase/decrease of DOS at the metal surface is not sufficient to explain the dependencies. Enlightening the underlying mechanism requires a detailed interface analysis to understand the influence of interface chemistry, stress and strain for the distinct sample and gating architecture. The role of oxygen at the interface has been found to be crucial. Reversible potential dependent oxidation and reduction reactions as well as oxygen hybridization have been discussed as origin for magnetic property changes [2-6]. Our concept follows this argumentation and seeks to by intention exploit reversible electrochemical surface reactions involving magnetic species. This allows addressing surface magnetism by an external voltage, opening the way to controlled electrical switching of magnetic properties.

In the present paper, the use of high aspect ratio metallic nanowires (NWs) as functional interconnects between three-dimensionally stacked chips is proposed. First practical preparation steps, as there are the preparation of templates and the deposition of Ag-NWs, are presented. Later on, the applicational technology for vertically aligned NWs is proposed as their embedment into a polymer matrix resulting in an anisotropically conductive composite film. This is discussed in both technological and functional aspects.

Two alternative preparation routes for FePt films are compared: pulsed laser deposition (PLD) and electrodeposition. It is described how an optimal microstructure can be obtained for best magnetic properties, and the advantages of both preparation routes are discussed. The low slope of the initial magnetization curve annealed at optimum conditions indicates that coercivity in electrodeposited granular films is controlled by pinning. In contrary, epitaxial films prepared by PLD on MgO(100) show that domain reversal in FePt films reaching the highest coercivity is governed by nucleation.