Fully Automated Wafer-Level Edge Coupling Measurement System for Silicon Photonics Integrated Circuits

In this work, we introduce a novel, fully automated wafer-level edge coupling measurement system designed specifically for silicon photonic integrated circuits (PICs). This system integrates state-of-the-art technologies, including optical probes, advanced alignment algorithms, and precision calibration processes, to ensure high coupling efficiency, rapid throughput, and exceptional repeatability. The optical probe, known as the Pharos lens, incorporates a periscope structure to facilitate effective vertical-to-horizontal light conversion, providing ultra-high coupling efficiency. The system also leverages adaptive optics algorithms to enhance measurement accuracy, compensating for optical aberrations and other distortions. Through extensive testing on 200 mm silicon wafers fabricated with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.25~\mu $ </tex-math></inline-formula>m photonic BiCMOS technology, we demonstrate that our system achieves consistent coupling efficiency with less than 0.2 dB of repeatability and remarkable stability, with fluctuations within 0.01 dB during 10-minute testing intervals. Our results underline the system’s ability to address the critical challenges in modern photonic testing and highlight its potential for improving manufacturing processes in the semiconductor and photonic industries.