Hybrid-bonded ic die having topographic surface features

An apparatus, comprising:

• an electronic integrated circuit (EIC);
• and
• a photonic integrated circuit (PIC) comprising a first region directly bonded to a first side of the EIC through a plurality of metallization features joined at a first bond interface, wherein the PIC comprises:
• a planar optical waveguide;
• and
• an optical coupler coupled to a length of the planar optical waveguide, wherein the optical coupler is with a second region of the PIC, adjacent to the first region, and protrudes from a surface of the PIC beyond an edge of the EIC;
• and
• wherein the EIC comprises a second, opposite, side comprising a second plurality of metallization features to directly bond the EIC to a host substrate.

A system comprising:

• a host substrate directly bonded to a first side of and electronic integrated circuit (EIC) through a plurality of first metallization features joined at a first bond interface;
• a photonic integrated circuit (PIC) comprising a first region directly bonded to a second side of the EIC through a plurality of second metallization features joined at a second bond interface, wherein the PIC comprises:
• a planar optical waveguide;
• and
• an optical coupler coupled to a length of the planar optical waveguide, wherein the optical coupler is with a second region of the PIC, adjacent to the first region, and protrudes from a surface of the PIC beyond an edge of the EIC;
• and
• a fiber connector affixed to the PIC, wherein the fiber connector is within a plane of the EIC between the host substrate and the PIC.