Integrated structure and manufacturing method thereof

An optoelectronic device, comprising:

• a first silicon layer having a bottom surface and a top surface;
• and
• a first waveguide in the first silicon layer, the first waveguide having a propagation region confined by:
• a base above the bottom surface and below the top surface, and
• a first sidewall extending from the base towards the top surface,
• wherein the propagation region of the first waveguide is further confined by a cap above the base, the first sidewall extending from the base to the cap.

An optoelectronic device, comprising:

• a first silicon layer having a bottom surface and a top surface;
• and
• a first waveguide in the first silicon layer, the first waveguide having a propagation region confined by:
• a base above the bottom surface and below the top surface, and
• a first sidewall extending from the base towards the top surface,
• wherein the base has an opening exposing the first waveguide to a portion of the first silicon layer below the base.

An optoelectronic device, comprising:

• a first silicon layer having a bottom surface and a top surface;
• and
• a first waveguide in the first silicon layer, the first waveguide having a propagation region confined by:
• a base above the bottom surface and below the top surface, and
• a first sidewall extending from the base towards the top surface,
• wherein the first waveguide is a rib waveguide comprising a slab region and a rib extending downward from the slab region toward the bottom surface,
• wherein the propagation region of the first waveguide is further confined by a second sidewall, and
• wherein the rib is defined by the base, the first sidewall, and the second sidewalls.