# US 9,435,948 B2 · Silicon waveguide structure with arbitrary geometry on bulk silicon substrate, related systems and program products

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- Number: US 9,435,948 B2
- Document ID: US9435948B2
- Status: Granted
- Kind: B2
- Application number: 14/304,318
- Filed: 2014-06-13
- Published: 2015-12-17
- Granted: 2016-09-06
- Earliest claimed: 2014-06-13
- Assignees: Globalfoundries Inc.
- Applicants: Globalfoundries Inc.
- Inventors: Robert K. Leidy; Mark D. Levy; Qizhi Liu; Gary L. Milo; Steven M. Shank
- Web page: https://patentgrep.com/patent/US9435948B2

## CPC

- G02B 6/122: Basic optical elements, e.g. light-guiding paths
- G02B 6/125: Bends, branchings or intersections
- G02B 6/136: by etching
- G02B 2006/12061: {Silicon}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

Various embodiments include a silicon-based optical waveguide structure locally on a bulk silicon substrate, and systems and program products for forming such a structure by modifying an integrated circuit (IC) design structure. Embodiments include implementing processes of preparing manufacturing data for formation of the IC design structure in a computer-implemented IC formation system, wherein the preparing of the manufacturing data includes inserting instructions into the manufacturing data to convert an edge of the at least one shape from a <110> crystallographic direction to a <100> crystallographic direction.

## Claims

### Claim 1

A silicon-based optical waveguide structure comprising:
a bulk silicon substrate;
a set of waveguide structures positioned within the bulk silicon substrate, wherein each of the set of waveguide structures includes:
a silicon dioxide (SiO2) layer filling a cavity within the bulk silicon substrate;
an intermediate layer directly over the SiO2 layer, the intermediate layer having a substantially flat lower surface contacting the SiO2 layer; and
a silicon layer overlying the intermediate layer,
wherein the SiO2 layer extends above the intermediate layer through the silicon layer.

### Claim 2 (depends on 1)

The silicon-based optical waveguide structure of claim 1, wherein the set of waveguide structures includes a plurality of waveguide structures.

### Claim 3 (depends on 2)

The silicon-based optical waveguide structure of claim 2, wherein one of the plurality of waveguide structures includes a non-uniform thickness region in the silicon layer overlying the intermediate layer.

### Claim 4 (depends on 3)

The silicon-based optical waveguide structure of claim 3, wherein the non-uniform thickness region includes a topographical difference in the silicon layer.

### Claim 5 (depends on 3)

The silicon-based optical waveguide structure of claim 3, wherein the non-uniform thickness region in the silicon layer is located between sections of the SiO2 layer extending through the silicon layer.

### Claim 6 (depends on 3)

The silicon-based optical waveguide structure of claim 3, wherein a second one of the plurality of waveguide structures does not include a non-uniform thickness region in the silicon layer overlying the intermediate layer.

### Claim 7 (depends on 6)

The silicon-based optical waveguide structure of claim 6, wherein the second one of the plurality of waveguide structures is adjacent the first one of the plurality of waveguide structures.

### Claim 8 (depends on 3)

The silicon-based optical waveguide structure of claim 3, wherein the intermediate layer separates the SiO2 in the cavity from the non-uniform thickness region.

### Claim 9 (depends on 1)

The silicon-based optical waveguide structure of claim 1, wherein the intermediate layer includes silicon.

### Claim 10 (depends on 1)

The silicon-based optical waveguide structure of claim 1, wherein the intermediate layer includes silicon germanium (SiGe).

### Claim 11 (depends on 1)

The silicon-based optical waveguide structure of claim 1, wherein the silicon layer is located between portions of the SiO2 layer.

### Claim 12 (depends on 4)

The silicon-based optical waveguide structure of claim 4, wherein the topographical difference includes at least one rib or protrusion.

### Claim 13

A silicon-based optical waveguide structure comprising:
a bulk silicon substrate;
a set of waveguide structures positioned within the bulk silicon substrate, wherein each of the set of waveguide structures includes:
a silicon dioxide (SiO2) layer filling a cavity within the bulk silicon substrate;
an intermediate layer directly over the SiO2 layer, the intermediate layer having a substantially flat lower surface contacting the SiO2 layer; and
a silicon layer overlying the intermediate layer,
wherein the SiO2 layer extends above the intermediate layer through the silicon layer,
wherein the set of waveguide structures includes a plurality of waveguide structures, wherein one of the plurality of waveguide structures includes a non-uniform thickness region in the silicon layer overlying the intermediate layer,
wherein a second one of the plurality of waveguide structures does not include a non-uniform thickness region in the silicon layer overlying the intermediate layer.

### Claim 14 (depends on 13)

The silicon-based optical waveguide structure of claim 13, wherein the non-uniform thickness region includes a topographical difference in the silicon layer.

### Claim 15 (depends on 13)

The silicon-based optical waveguide structure of claim 13, wherein the non-uniform thickness region in the silicon layer is located between sections of the SiO2 layer extending through the silicon layer.

### Claim 16 (depends on 13)

The silicon-based optical waveguide structure of claim 13, wherein the second one of the plurality of waveguide structures is adjacent the first one of the plurality of waveguide structures.

### Claim 17 (depends on 13)

The silicon-based optical waveguide structure of claim 13, wherein the intermediate layer separates the SiO2 in the cavity from the non-uniform thickness region.

### Claim 18 (depends on 13)

The silicon-based optical waveguide structure of claim 13, wherein the intermediate layer includes silicon.

### Claim 19 (depends on 13)

The silicon-based optical waveguide structure of claim 13, wherein the intermediate layer includes silicon germanium (SiGe).