3D Silicon Photonics Interposer for Tb/s Optical Interconnects in Data Centers with Double-Side Assembled Active Components and Integrated Optical and Electrical Through Silicon Via on SOI

In this paper, we present the concept, fabrication, process and packaging of a 3D Si photonics interposer. This Si photonics interposer merges passive photonic and electronic functionalities within a single chip. The interposer is populated with active optical and electronic add-ons, which are flip-chip bonded to the interposer using thermo-compression bonding. The interposer itself is then flip-chip bonded to a glass and Si carrier for further testing purposes. This integration concept enables a high connection density (Gb/s/mm²) by assembling 40Gb/s per channel opto-electrical components on both sides of the interposer. Communication between components on both sides of the interposer is enabled by optical and electrical TSVs with a 3dB bandwidth >28GHz. A single mode photonic layer, designed for 1.55µm wavelength is integrated within the interposer to be used for routing and switching of the optical signals. Main fabrication and packaging steps are described here, together with some demonstrator evaluation results.