Broadband Optical Engine System Integration by Wafer Level Process in HPC/AI Era

A novel broadband optical engine (BOE) of silicon photonics featuring the system integration of COUPE (Compact Universal Photonic Engine), COI (Complimentary Optical Interconnect) and iFAU (Integrated Fiber Array Unit) for CPO (Co-Packaged Optics) of 2.5D CoWoS® is presented. COI is a BOE enabler featuring paired advanced couplers and optic structures, to redirect optical signals from iFAU fibers to optical waveguides (WG) to photonics chiplet at low optical loss. The BOE technology features wafer level process and monitor for manufacturability and bandwidth density scalability through multi-wavelengths and iFAU with multi-rows fibers. Furthermore, BOE features vertical coupling which the optical performance has a broad tolerance to the chip warpage, while edge coupling (EC) does not. In this study, we report the measured optical performance of BOE through a 300 mm wafer process and modeling data analysis. The difference of optical performance between measured data and modeling shows the importance of process control in critical dimensions of optics such as width, height, profile, surface conditions, and alignment accuracy.