AIM Photonics Demonstration of a 300 mm Si Photonics Interposer

The American Institute for Manufacturing Integrated Photonics (AIM Photonics) is developing a Si photonic interposer platform (a.k.a. active interposer) to enable 3D co-packaged optics. It is a 100 μm thick Si interposer, built on a 300mm Si wafer, with in-situ photonic layers that support a full suite of active and passive components, including low-loss Si and SiN waveguides, edge couplers, photodetectors, and modulators. The active interposer is achieved through 3D wafer bonding the Si photonics layers to a Si interposer with 100 μm tall through-silicon vias (TSVs). A backside Cu redistribution layer (RDL) enables fan-out to a built-in ball grid array (BGA) for connection to a printed circuit board (PCB) without wire bonds. Additionally, the platform includes packaging processes for III-V laser flip-chip attach directly inside trenches within the interposer photonic layers for edge coupling to SiN waveguides, electronic integrated circuit (EIC) flip-chip attach on the top surface of the interposer to minimize electrical interconnection to the photonics layer, and edge-coupled fiber arrays for optical I/O. We will present our latest results and the challenges associated with the 3D assembly (i.e. wafer bonding and thinning processes). Packaging the various components will be discussed, and optical and electrical device performance will be presented and compared with our base Si photonics process from the APSUNY AIM Photonics / Analog Photonics Base Active Process Design Kit (PDK).