Scalable 3D Silicon Photonic Electronic Integrated Circuits and their Applications

This paper investigates the opportunity and challenges of 3D silicon photonic electronic integrated circuits (3D EPICs) scaling to wafer-scale and beyond. The continuing demand for more data and information is driving new computing, communications, imaging, and information processing at higher throughput and energy-efficiency at lower manufacturing cost. The newly developed 3D silicon photonic devices including vertical U-turns and vertical lightpipes enable through-silicon-optical-vias (TSOVs) that can interconnect multiple layers of 2D silicon photonic electronic integrated circuits consistently with the industry's through-silicon-via (TSV) based 3D electronic integrated circuit manufacturing. Heterogeneous integration technology based on transfer printing allows wafer-scale (or beyond wafer-scale) heterogeneous integration of dissimilar materials (e.g., III-V semiconductor layers) on silicon at room temperature and 3D ultrafast laser inscription technologies allow arbitrary optical interfaces for high-density input/output between the 3D EPICs and many strands of multi-core-fibers (MCFs). We will discuss applications in neuromorphic computing, 3D LiDAR, photonic-integrated-interferometric-telescopes, 3D-fine-grain-memory, and 3D processor-memory realized by large-scale 3D EPICs.