US Patent 11698489 Photonic package device and method for fabricating the same

A method for fabricating a photonic package device is provided. The method includes patterning a semiconductor layer of a semiconductor-on-insulator (SOI) substrate into a waveguide structure and at least one first semiconductor pillar; forming a metal-dielectric stack over the waveguide structure and the first semiconductor pillar; etching an opening in the metal-dielectric stack to expose the first semiconductor pillar; etching an insulator layer of the SOI substrate to form at least one insulator cap below the first semiconductor pillar; and etching a base semiconductor substrate of the SOI substrate to form at least one second semiconductor pillar below the insulator cap.