Optical integrated circuit structure including edge coupling protective features and method of forming same

An optical integrated circuit (IC) structure comprising:

• a substrate comprising a fiber slot formed in an upper surface of the substrate and extending from an edge of the substrate, and an undercut formed in the upper surface and extending from the fiber slot;
• a semiconductor layer disposed on the substrate;
• a dielectric structure disposed on the semiconductor layer;
• vents that extend through a coupling region of the dielectric structure and expose the undercut;
• and
• a dielectric material disposed on surfaces of the vents, the undercut, and the fiber slot.

An optical integrated circuit (IC) structure comprising:

• a substrate comprising a fiber slot formed in an upper surface of the substrate and extending from an edge of the substrate, and an undercut formed in the upper surface and extending from the fiber slot;
• a semiconductor layer disposed on the substrate and comprising an optical waveguide disposed over the undercut;
• inter-metal dielectric (IMD) layers disposed on the semiconductor layer;
• and
• vents that extend through the IMD layers and the semiconductor layer to expose the undercut.