Silicide Thermal Heaters for Silicon-on-Insulator Nanophotonic Devices

• US 20110002576A1
• Filed: 09/04/2007
• Published: 01/06/2011
• Est. Priority Date: 09/04/2007
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hamann, Hendrik F., Vlasov, Yurii A., Green, William M.
• Granted Patent: US 8,098,968 B2
• Time in Patent Office: Days
• US Class Current: 385/4
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 2006/12145 Switch
• CPC Class Codes: G02B 2006/12147 Coupler
• CPC Class Codes: G02B 6/125 Bends, branchings or intersections
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence

Abstract

A thermally switched Silicon-On-Insulator (SOI) photo electronic device includes a silicon layer including an optical waveguide and a silicide heating element horizontally adjacent to the waveguide. The waveguide has a refractive index that changes with heat applied to the waveguide.

Claims

1. A thermally-switched photo electronic device comprising a silicon layer disposed over an oxide layer, the silicon layer comprising:

an optical waveguide comprising a refractive index; and

a resistive heating element embedded within the silicon layer and located horizontally adjacent and in close proximity to the optical waveguide and the silicon layer for generating heat to the optical waveguide so that the refractive index changes in response to the heat.

2. The device of claim 1, wherein the resistive heating element comprises a silicide material.

3. The device of claim 2, wherein the silicide material comprises nickel silicide.

4. The device in claim 2 wherein the silicide material comprises cobalt silicide.

5. The device in claim 2 wherein the silicide material comprises titanium silicide.

6. The device in claim 1 wherein the optical waveguide comprises a deep rib waveguide etched into the silicon layer.

7. The device in claim 6 wherein the waveguide further comprises single mode guiding for achieving low propagation loss.

8. The device of claim 1, wherein the photo electronic device comprises a filter.

9. The device of claim 8, wherein the heating element is placed horizontally adjacent to the optical waveguide at a distance that enhances thermal conductivity to said optical waveguide.

10. The device of claim 6, wherein the optical waveguide is surrounded by a thin slab of silicon.

11. The device of claim 1 wherein the heating element is located at a distance of 250-1000 nanometers from the optical waveguide.

12. The device of claim 10 wherein strong confinement of the optical mode within the optical waveguide allows the heating element to be within 0.5 micrometers to an edge of the optical waveguide without inducing optical loss.

13. A method of fabricating a photo electronic device, the method comprising:

fabricating a silicon layer over an oxide layer, the silicon layer fabricated by a method comprising;

etching a deep rib optical waveguide in the silicon layer over the oxide layer, the waveguide comprising an index of refraction; and

forming a thin heating element horizontally adjacent and in close proximity to the waveguide such that the index of refraction changes as a function of variations of heat produced by the heating element.

14. The method of claim 13 wherein forming the heating element comprises including a silicide material.

15. The method of claim 14 wherein forming the resistive heating element comprises including nickel silicide in the heating element.

16. The method of claim 14 wherein forming the resistive heating element comprises including cobalt silicide in the heating element.

17. The method of claim 13 further comprising producing the waveguide with single mode guiding.

18. The method of claim 13 further comprising placing the heating element horizontally adjacent to the waveguide with a short gap between the heating element and the waveguide for enhancing thermal conductivity to the waveguide.

19. The method of claim 13 wherein forming a thin heating silicide element comprises locating the heating element within a range of 250-1000 nanometers from the waveguide.

20. The method of claim 13 further comprising placing the thermal heater within 0.5 micrometers to the edge of the waveguide without inducing optical loss.

21. A thermally-switched photo electronic device comprising a silicon layer disposed over an oxide layer, the silicon layer comprising:

a plurality of optical waveguides comprising refractive indices, wherein the optical waveguides are optically separated by a gap; and

a resistive heating element thermally coupled with each optical waveguide, the resistive heating element embedded within the silicon layer and located horizontally adjacent and in close proximity to its associated optical waveguide and the silicon layer for generating heat to its associated optical waveguide so that the refractive index changes in response to the heat.

22. The device of claim 21 wherein each of the plurality of optical waveguides are nanophotonic rib waveguides.

23. The device of claim 22 wherein the waveguides are actuated independently.

24. The device of claim 23 wherein the gap is etched into the silicon layer.

25. The device of claim 24 wherein a width of the gap determines interaction of the waveguides.