Photonic semiconductor device and method of manufacture

A structure comprising:

• a photonic device connected to a package substrate, wherein the photonic device comprises:
• an interconnect structure;
• and
• a photonic die connected to the interconnect structure, wherein the photonic die comprises a waveguide and a plurality of edge couplers, wherein a first sidewall surface of the photonic die is offset from a sidewall of the interconnect structure;
• an optical fiber holder over the package substrate;
• a plurality of optical fibers held by the optical fiber holder, wherein each optical fiber of the plurality of optical fibers is optically coupled to a respective edge coupler of the plurality of edge couplers;
• and
• an optical glue covering the first sidewall surface and at least partially surrounding the optical fiber holder.

A method comprising:

• depositing a first sacrificial material on a sidewall of a photonic package, wherein the photonic package comprises a waveguide;
• performing a sawing process through the first sacrificial material, wherein the first sacrificial material remains on the sidewall of the photonic package after the sawing process;
• removing the first sacrificial material;
• attaching the photonic package to a substrate;
• depositing a second sacrificial material on the sidewall and on the substrate;
• depositing an underfill between the photonic package and the substrate;
• and
• after depositing the underfill, removing the second sacrificial material.