INTERPOSER AND METHOD FOR PRODUCING A LIGHT-GUIDING STRUCTURE

• US 20030103712A1
• Filed: 02/05/2001
• Published: 06/05/2003
• Est. Priority Date: 02/05/2001
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: McCormack, Mark, Glebov, Alexei
• Granted Patent: US 6,603,915 B2
• Time in Patent Office: Days
• US Class Current: 385/14
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/1221 made from organic materials
• CPC Class Codes: G02B 6/125 Bends, branchings or intersections
• CPC Class Codes: G02B 6/132 by deposition of thin films
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA

Abstract

An interposer and method for producing an interposer. The method comprises forming in a substrate a cladding layer having a known density value; and forming in the substrate a waveguide core layer in contact with the cladding layer and also having a known density value which is greater than the density value of the cladding layer. The method further includes forming in the substrate a second cladding layer in contact with the waveguide core layer and having a known density value less than the density value of the waveguide core layer. A method for producing a light-guiding structure comprising forming in a substrate a cladding layer having a top substrate surface and a porosity value; and forming in the substrate a waveguide core layer in contact with the cladding layer and having a porosity value less than the porosity value of the cladding layer. The method also includes forming in the substrate another cladding layer in contact with the waveguide core layer and having a porosity value greater than the porosity value of the waveguide core layer. The two cladding layers and the waveguide core layer terminate in the top substrate surface of the substrate.

Claims

1. A method for producing light-guiding structure comprising:

providing a substrate having a top substrate surface;

forming in the substrate a first cladding layer having a first porosity value and terminating in said top substrate surface;

forming in the substrate a waveguide core layer in contact with the first cladding layer and having a second porosity value less than the first porosity value and terminating in said top substrate surface; and

forming in the substrate a second cladding layer in contact with the waveguide core layer and having a third porosity value greater than the second porosity value and terminating in said top substrate surface.

2. The method of claim 1 wherein said second cladding layer has a top cladding surface which is generally aligned with the top substrate surface.

3. The method of claim 2, wherein said second cladding layer has a top cladding surface which is generally aligned with the top substrate surface.

4. The method of claim 1 wherein said first porosity value generally equals said third porosity value.

5. The method of claim 4, wherein said first porosity value generally equals said third porosity value.

6. The method of claim 1 wherein said first cladding layer and said second cladding layer comprise silicon.

7. The method of claim 1 additionally comprising expanding said first cladding layer, said waveguide core layer, and said second cladding layer.

8. The method of claim 1 additionally comprising oxidizing said first cladding layer, said waveguide core layer, and said second cladding layer..

10. The method of claim 1 additionally comprising determining the first porosity value of intended first cladding layer prior to forming said first cladding layer.

11. The method of claim 10 wherein said determining of said first porosity value comprises providing a value for a width of first cladding layer, and finding the angle of a first plane along a first side of intended first cladding layer with a second plan tangential to a second side of intended first cladding layer at a point of intersection of the first plane with the second-side.

9. A method for producing an interposer comprising:

providing a substrate having a top substrate surface;

forming in the substrate a first cladding layer having a first density value and terminating in said top substrate surface;

forming in the substrate a waveguide core layer in contact with the first cladding layer and having a second density value greater than the first density value and terminating in said top substrate surface; and

forming in the substrate a second cladding layer terminating in said top substrate surface and in contact with the waveguide core layer and having a third density value less than the second density value and terminating in said top substrate surface.

12. An interposer comprising a silicon body having a silicon surface, a first cladding layer including a pair of first opposed cladding layer ends and extending through said silicon body and having said first opposed cladding layer ends terminating in said silicon surface;

a core layer including a pair of opposed core layer ends and extending through said silicon body in contact with said first cladding layer and having said opposed core layer ends terminating in said silicon surface; and

a second cladding layer including a second cladding surface and disposed in said silicon body in contact with said core layer and such that said second cladding surface is generally aligned with said silicon surface,

13. The interposer of claim 12 wherein said first cladding layer and said second cladding layer have a porosity ranging from about 20% to about 80%.

14. The interposer of claim 13 wherein said core layer has a porosity which is less than the porosity of the first and second cladding layers.

15. The interposer of claim 14 wherein said core layer has a porosity ranging from about 25% to about 50%.