Photonic package device and method for fabricating the same

1. A method for fabricating a photonic package device, comprising:

patterning a semiconductor layer of a semiconductor-on-insulator (SOI) substrate into a waveguide structure and at least one first semiconductor pillar;

forming a metal-dielectric stack over the waveguide structure and the first semiconductor pillar;

etching an opening in the metal-dielectric stack to expose the first semiconductor pillar;

etching an insulator layer of the SOI substrate to form at least one insulator cap below the first semiconductor pillar; and

etching a base semiconductor substrate of the SOI substrate to form at least one second semiconductor pillar below the insulator cap.

2. The method of claim 1 , further comprising:

forming a patterned mask over the metal-dielectric stack prior to etching the opening in the metal-dielectric stack, wherein etching the opening in the metal-dielectric stack is performed with the patterned mask in place.

3. The method of claim 2 , wherein etching the insulator layer is performed with the patterned mask in place.

4. The method of claim 3 , wherein etching the base semiconductor substrate is performed with the patterned mask in place.

5. The method of claim 1 , wherein etching the base semiconductor substrate is performed such that the first semiconductor pillar is removed to expose a top surface of the insulator cap.

6. The method of claim 1 , wherein the patterning the base semiconductor layer is performed such that the semiconductor layer is further patterned into a peripheral structure surrounding the first semiconductor pillar, and etching the opening in the metal-dielectric stack is performed such that the opening further exposes an edge portion of the peripheral structure.

7. The method of claim 1 , further comprising:

bonding a light source device onto the base semiconductor substrate, wherein the light source device is in the opening in the metal-dielectric stack and supported by the insulator cap and the second semiconductor pillar.

8. A method for fabricating a photonic package device, comprising:

patterning a semiconductor layer of a semiconductor-on-insulator (SOI) substrate into a waveguide structure and a peripheral structure, wherein the peripheral structure has a first opening and an edge portion adjacent the first opening;

filling the first opening of the peripheral structure with a dielectric layer;

forming a metal-dielectric stack over the waveguide structure, the peripheral structure, and the dielectric layer;

etching a second opening in the metal-dielectric stack to expose the edge portion of the peripheral structure; and

etching an insulator layer and a base substrate of the SOI substrate through the second opening to form a recess in the SOI substrate and an edge supporting structure surrounding the recess.

9. The method of claim 8 , further comprising:

forming a patterned mask over the metal-dielectric stack prior to etching the second opening in the metal-dielectric stack, wherein etching the second opening in the metal-dielectric stack is performed with the patterned mask in place.

10. The method of claim 9 , wherein etching the insulator layer and the base substrate is performed with the patterned mask in place.

11. The method of claim 8 , wherein etching the insulator layer and the base substrate comprises:

using the edge portion of the peripheral structure as etch mask, performing a first selective etching process to etch the insulator layer to form an insulator cap of the edge supporting structure; and

using the insulator cap as etch mask, performing a second selective etching process to etch the base substrate.

12. The method of claim 11 , wherein the second selective etching process is performed such that the edge portion of the peripheral structure is removed to expose a top surface of the insulator cap of the edge supporting structure.

13. The method of claim 8 , wherein patterning the semiconductor layer is performed such that the edge portion of the peripheral structure comprises a semiconductor wall pillar.

14. The method of claim 8 , further comprising:

bonding a light source device onto the base substrate, wherein the light source device is in the second opening in the metal-dielectric stack and supported by the edge supporting structure.

15. A photonic package device, comprising:

a semiconductor substrate comprises at least one semiconductor pillar and a semiconductor structure surrounding the semiconductor pillar;

a waveguide structure over a first portion of the semiconductor structure of the semiconductor substrate;

a metal-dielectric stack over the waveguide structure, wherein the semiconductor pillar and a second portion of the semiconductor structure are free from coverage by the metal-dielectric stack; and

a light source device supported by the semiconductor pillar and the second portion of the semiconductor structure.

16. The photonic package device of claim 15 , wherein the semiconductor structure has a sidewall facing the semiconductor pillar.

17. The photonic package device of claim 15 , further comprising:

an insulator cap over the semiconductor pillar; and

an insulator layer having a first portion between the first portion of the semiconductor structure and the waveguide structure and a second portion over the second portion of the semiconductor structure.

18. The photonic package device of claim 15 , wherein the second portion of the semiconductor structure is a semiconductor wall pillar.

19. The photonic package device of claim 15 , wherein the semiconductor structure has a third portion free from coverage by the metal-dielectric stack, and the second and third portions of the semiconductor structure are at opposite sides of the semiconductor pillar.

20. The photonic package device of claim 15 , wherein the second portion of the semiconductor substrate encircles a plurality of the semiconductor pillars from a top view.