Overall objective of the European project PARADIGM is to effect a fundamental change in the way photonic integrated circuits (PICs) based on indium phosphide (InP) are designed and manufactured in Europe, with the aim of reducing the costs of design, development and manufacture by more than an order of magnitude and making more complex and capable designs possible than ever before.
Within the project, Fraunhofer IZM is investigating the design and manufacturing of photonic integrated circuits (PICs). One key step is the development of a platform technology for application specific systems containing PICs. Here, Fraunhofer IZMs research efforts are working towards a II-V semiconductor-compatible silicon interposer technology.
Here, Fraunhofer IZM successfully developed a through silicon via (TSV) technology in gold featuring TSVs and a patterned double-sided metallization. Such a copper-free metallization is an important technology for photonic packaging ((III-V semiconductors). Test vehicles with a coplanar waveguide and TSVs have been realized and compared to a conventional wire bonded waveguide. The TSVs have diameter of 200 µm and a depth of 400 µm, the waveguide length is 100 mm. The target was to reduce the crosstalk and attenuation by using TSVs. The measurements carried out by the project partner CIP show a significant performance gain. The attenuation was considerably lower (2 db at 40 GHz) and the crosstalk showed a more flat course.
Fraunhofer Institute for Reliability and Microintegration IZM