Challenges In Co-Packaging Of SI-III/V Components In Silicon Photonics

Abstract In the modern semiconductor industry, Silicon photonics stands at the forefront as an emerging interdisciplinary department that seeks to combine photonics and electronics on a singular silicon substrate. This combination of conventional electronic circuits and the rapid data transmission capabilities of optical communication has attracted substantial attention due to its potential to transform data communication, computing, sensing and more. Silicon photonics attempts to convert electronic signals into optical signals, facilitating data transmission at remarkable velocities. This is achieved by leveraging photonic components such as waveguides, modulators, detectors, and multiplexers all meticulously engineered using conventional silicon fabrication methodologies. The major component in silicon photonics is the silicon waveguide, a small structure that steers light, enabling its propagation with minimal attenuation. III-V materials such as Gallium Arsenide (GaAs) and Indium Phosphide (InP) are used as substrates of opto-electronic devices like vertical cavity surface emitting lasers (VCSEL), edge emitting lasers and light emitting diodes. System in Package integration of the III-V materials to silicon requires a reliable bonding technique. The present study proposes four different interconnect design namely Annular, semi-annular, flat pad and solder balls between GaAs substrate and SOI wafer. A finite element model of the package is created using Ansys and analyzed using Ansys Thermal module. Different designs are evaluated for their thermal and reliability performances in the GaAs/Si integrated circuits. The advantages and short comings of each interconnect design is discussed and suggestions are made about the affinity of each configuration for different applications