Light deflection structure to increase optical coupling

1 . A method for forming a semiconductor structure, comprising:

forming a plurality of photonic devices in a first substrate layer, wherein the photonic devices are laterally spaced apart from one another and disposed within an inner device region;

forming an insulator structure around the photonic devices;

forming a lower dielectric structure on a back-side surface of the first substrate layer;

forming an edge coupler in the lower dielectric structure and within the inner device region;

forming a patterned masking layer along a lower surface of the lower dielectric structure;

etching the lower dielectric structure with the patterned masking layer in place to form an opening extending into the lower surface of the lower dielectric structure;

forming a deflector structure within the opening, wherein the deflector structure is disposed within a peripheral region laterally adjacent to the edge coupler and laterally offset from the plurality of photonic devices by a non-zero distance; and

depositing a lower insulator structure along a surface of the deflector structure and sidewalls of the lower dielectric structure.

2 . The method of claim 1 , wherein the lower dielectric structure is etched such that an upper surface of the lower dielectric structure is slanted relative to the lower surface of the lower dielectric structure.

3 . The method of claim 1 , further comprising:

forming a plurality of first waveguides within the lower dielectric structure, wherein at least one waveguide in the plurality of first waveguides is formed concurrently with the edge coupler.

4 . The method of claim 1 , further comprising:

forming a first interconnect structure over the plurality of photonic devices;

bonding an electronic IC structure to the first interconnect structure;

bonding a second substrate to the electronic IC structure; and

forming a first input/output (I/O) structure within the second substrate, wherein the first I/O structure directly overlies the deflector structure.

5 . The method of claim 1 , wherein the edge coupler comprises a plurality of optical core segments having one or more sidewalls facing a surface of the deflector structure, wherein when viewed in cross section the optical core segments are arranged in a cross-like layout.

6 . The method of claim 1 , wherein forming the deflector structure comprises:

bonding the deflector structure to the insulator structure.

7 . The method of claim 6 , further comprising:

forming a dielectric layer between the deflector structure and the sidewalls of the lower dielectric structure.

8 . The method of claim 1 , wherein a lateral distance between the deflector structure and the edge coupler is less than a width of the deflector structure.

9 . The method of claim 1 , wherein the edge coupler directly underlies a bottom surface of a first photonic device in the plurality of photonic devices.

10 . A method for forming an integrated chip, comprising:

forming a first dielectric structure having a first surface over a second surface;

forming one or more photonic devices in the first dielectric structure;

forming an optical input/output (I/O) structure over the first surface of the first dielectric structure wherein forming the optical I/O structure comprises:

bonding a substrate to the first dielectric structure;

etching the substrate to form a lens structure in the substrate, wherein an upper surface of the lens structure is vertically below a top surface of the substrate;

depositing a liner layer on the lens structure; and

depositing a first insulator layer on the liner layer, wherein the optical I/O structure comprises the lens structure, the liner layer, and the first insulator layer; and

forming an edge coupler in a second dielectric structure on the second surface of the first dielectric structure, wherein the edge coupler is laterally offset from the optical I/O structure; and

forming a deflector structure in the second dielectric structure and under the optical I/O structure, wherein the deflector structure is laterally offset from the edge coupler by a non-zero distance and the deflector structure comprises a material different from that of the edge coupler.

11 . The method of claim 10 , further comprising:

forming one or more waveguides in the second dielectric structure, wherein the one or more waveguides are optically coupled to the edge coupler.

12 . The method of claim 10 , wherein the deflector structure comprises a curved surface facing the edge coupler.

13 . The method of claim 10 , further comprising:

forming an interconnect structure on the first surface of the first dielectric structure, wherein the interconnect structure comprises a plurality of conductive interconnects and one or more waveguides arranged in an interconnect dielectric structure;

bonding an electronic integrated circuit (IC) to the interconnect structure; and

bonding an optical source structure to the interconnect structure, wherein the optical I/O structure is vertically above the electronic IC and the optical source structure.

14 . The method of claim 13 , wherein the electronic IC, the optical source structure, and the one or more photonic devices are arranged laterally in a device region, wherein the optical I/O structure and the deflector structure are arranged laterally in a peripheral region adjacent to the device region.

15 . The method of claim 10 , wherein forming the deflector structure comprises:

etching the second dielectric structure to form a lateral surface and opposing sidewalls in the second dielectric structure;

forming a first layer on the lateral surface, wherein the first layer comprises a plurality of segments laterally offset from one another; and

forming a second layer on the lateral surface and between the plurality of segments, wherein a refractive index of the first layer is different from a refractive index of the second layer.

16 . The method of claim 15 , further comprising:

forming a second insulator layer on the first and second layers and along the opposing sidewalls of the second dielectric structure, wherein the second insulator layer comprises a material different from that of the first layer and the second layer.

17 . The method of claim 10 , wherein forming the deflector structure comprises:

etching the second dielectric structure to form a deflector opening in the second dielectric structure; and

depositing a stack of deflector layers on a surface of the second dielectric structure that at least in part defines the deflector opening, wherein the surface of the second dielectric structure faces the edge coupler, wherein the stack of deflector layers comprises a plurality of first deflector layers alternatively stacked with a plurality of second deflector layers, wherein the first deflector layers comprise a first material and the second deflector layers comprise a second material different from the first material.

18 . A method for forming an integrated chip, comprising:

patterning a device layer that overlies a first substrate to form a plurality of optical devices;

depositing a first dielectric structure over the first substrate and around the plurality of optical devices;

forming an interconnect structure on a first surface of the first dielectric structure;

forming a first optical input/output (I/O) structure over the interconnect structure;

removing the first substrate;

forming a second optical I/O structure in a second dielectric structure on a second surface of the first dielectric structure, wherein the second surface of the first dielectric structure underlies the first surface of the first dielectric structure;

patterning the second dielectric structure to form an opening in the second dielectric structure, wherein the opening underlies the first optical I/O structure and is laterally adjacent to the second optical I/O structure; and

forming a deflector structure in the opening.

19 . The method of claim 18 , wherein a height of the deflector structure is greater than a height of the second optical I/O structure.

20 . The method of claim 18 , wherein the deflector structure comprises a metal.