Novel cost effective butt-coupled PIN germanium photodetector integrated in a 200mm silicon photonic platform

Silicon photonics is becoming a technology of choice for optical communications. Compatibility with cmos manufacturing process is one key of success since it allows taking advantage of the production capacities of foundries; i.e. big volume and low cost manufacturability [1]. Germanium is the ideal candidate to build the integrated high performance photodiodes needed for receiver circuits [2]. Meanwhile, pure Ge epitaxy is not common in cmos processes and its integration within a silicon platform is not straightforward. In particular, germanium is very sensitive to wet etch processes. Post Ge-epitaxy dopant activation is also difficult due to thermal budget limitations. In this work, we propose a novel photodetector architecture which is integrated in a silicon photonic platform in a cost effective and robust manner.