Within this paper, we describe architecture and functionality of the Wide Field Imager (WFI) control and data processing electronics. WFI is one of two scientific instruments of the next European X-ray observatory ATHENA whose development started five years ago. A conceptual design, development models and a number of technology development activities have been performed and results will be shown.

The Wide Field Imager is one of two instruments on-board the future ATHENA X-ray observatory. Its main scientific objective is to perform a sky survey in the energy range of 0.2 keV up to 15 keV with an end-of-life spectral resolution (FWHM) better than 170 eV (at 7 keV) and a frame rate of at least 200 Hz. The field of view will be 40 arcmin squared wherefore a focal plane array with 4 large sensors each with a size of 512 times 512 pixels will be developed. Additionally, a fast detector with a size of 64 times 64 pixels and a frame rate of 12.5 kHz will be implemented in order to enhance the instrument with high count rate detection of bright sources. The data processing electronics within the WFI instrument is distributed over several subsystems: DEPFET sensors sensitive in the x-ray energy regime and front-end electronics are located inside the Camera Head. Data pre-processing inside the Detector Electronics will be performed in an FPGA-based frame-processor. FPGA external memory will be used to store offset and noise maps wherefore memory controllers have to be developed. Fast read and write access to the maps combined with robustness against radiation damage (e.g. bit-flips) has to be ensured by the frame-processor design.

Electroplated Cu is being used by the major semiconductor manufacturers as an interconnect material, because it offers a lower line resistance and better electromigration performance over conventional Al metallization. This paper describes the mechanism of "super-fill" as well as gap fill, microstructure, and film composition of electroplated copper. A combination of optimized Cu plating additive chemistry and current waveform enable complete gap fill of 0.07-0.1 /spl mu/m features (AR>10:1) as well as strong [111] texture, large grains (>3 /spl mu/m) with a large fraction of twin grain boundaries and controlled impurity content in electroplated Cu films. Electroplating process stability was maintained through the on-line analysis (p/t<0.3) of organic and inorganic bath ingredients and their replenishment.

We have investigated the planarizing effects of multilayered superconducting thin films. Atomic force microscopy measurements indicate that coating a standard niobium base electrode with alternating layers of aluminum and niobium significantly reduces the film's overall surface roughness. Planarized films such as these were used as the base electrodes of superconducting tunnel junctions that show vastly improved leakage characteristics over conventional junctions fabricated under the same conditions. (C) 1998 American Institute of Physics.