# US 11,079,544 B2 · Waveguide absorbers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,544 B2 - Document ID: US11079544B2 - Status: Granted - Kind: B2 - Application number: 16/531,819 - Filed: 2019-08-05 - Published: 2021-02-11 - Granted: 2021-08-03 - Earliest claimed: 2019-08-05 - Assignees: GlobalFoundries U.S. Inc. - Applicants: Globalfoundries U.S. Inc. - Inventors: Yusheng Bian; Bo Peng; Michal Rakowski; Ajey Poovannummoottil Jacob - Web page: https://patentgrep.com/patent/US11079544B2 ## CPC - G02B 6/125: Bends, branchings or intersections - G02B 6/243: {as light absorbers} - G02B 2006/12126: {Light absorber} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract The present disclosure relates to semiconductor structures and, more particularly, to Waveguide absorbers and methods of manufacture are provided. The waveguide structure includes a photonics component and a spirally configured waveguide absorber coupled to a node of the photonics component which reduces optical return loss. ## Claims ### Claim 1 A structure comprising: a photonics component; and a spirally configured waveguide absorber comprising an input end that is coupled to a node of the photonics component which reduces optical return loss, wherein the spirally configured waveguide absorber is composed of a combination of semiconductor materials, with at least one passivation layer contacting a first of the semiconductor materials and with another passivation layer encapsulates or seals the first of two semiconductor materials. ### Claim 2 (depends on 1) The structure of claim 1, wherein the photonics component is a photonic waveguide structure composed of Si or SiN. ### Claim 3 (depends on 2) The structure of claim 2, wherein the spirally configured waveguide absorber and the photonics component is integrated into a semiconductor monolithic structure. ### Claim 4 (depends on 2) The structure of claim 2, wherein the Si material is silicon on insulator (SOI) technologies. ### Claim 5 (depends on 2) The structure of claim 2, wherein the spirally configured waveguide absorber is composed of dielectric material. ### Claim 6 (depends on 2) The structure of claim 2, wherein the spirally configured waveguide absorber is composed of Si, SiN or polysilicon. ### Claim 7 (depends on 6) The structure of claim 6, wherein the spirally configured waveguide absorber is concentrically placed spiral circular turns or concentrically placed rectangular turns. ### Claim 8 (depends on 1) The structure of claim 1, further comprising a coupler coupling the spirally configured waveguide absorber to the photonics component and the photonics component comprises a different material than the spirally configured waveguide absorber. ### Claim 9 (depends on 8) The structure of claim 8, wherein the coupler includes a first tapered portion extending from the photonics component and a second tapered portion extending from the spirally configured waveguide absorber. ### Claim 10 (depends on 1) The structure of claim 1, wherein the waveguide absorber includes roughened sides. ### Claim 11 (depends on 1) The structure of claim 1, wherein the semiconductor materials of the spirally configured waveguide absorber are composed of a combination of Ge material and Si material, with a first passivation layer contacting the Ge material, the another passivation layer composed of SiN layer contacting the first passivation layer, and the first passivation layer and the SiN material encapsulating or sealing the Ge material. ### Claim 12 A structure comprising: a semiconductor waveguide component; and a spirally configured waveguide absorber coupled to and integrated into a semiconductor monolithic structure with the semiconductor waveguide component, the spirally configured waveguide absorber comprising a combination of Ge material and Si material, with one or more passivation layers contacting the Ge material and a SiN layer contacting the one or more passivation layers, the one or more passivation layers and the SiN material encapsulating or sealing the Ge material. ### Claim 13 (depends on 12) The structure of claim 12, wherein the spirally configured waveguide absorber is concentrically placed spiral circular turns or concentrically placed rectangular turns. ### Claim 14 (depends on 12) The structure of claim 12, wherein the spirally configured waveguide absorber is composed of dielectric material or polysilicon and a tapered coupler couples the spirally configured waveguide absorber to the semiconductor waveguide component. ### Claim 15 (depends on 14) The structure of claim 14, wherein the coupler includes a first tapered portion of same material as the semiconductor waveguide component and a second tapered portion of a same material of the spirally configured waveguide absorber. ### Claim 16 (depends on 14) The structure of claim 14, wherein the coupler includes a first tapered portion and a second tapered portion of a same material with different etching depths. ### Claim 17 (depends on 12) The structure of claim 12, wherein the waveguide absorber includes roughened sides. ### Claim 18 A structure comprising: a semiconductor waveguide component; a rectangular or circular concentrically spiraled waveguide absorber composed of dielectric material or poly silicon; and a tapered coupler coupling the rectangular or circular concentrically spiraled waveguide absorber to the semiconductor waveguide component, the coupler including a first tapered portion of same material as the semiconductor waveguide component and a second tapered portion of a same material of the rectangular or circular concentrically spiraled waveguide absorber, wherein the first tapered portion and the second tapered portion comprise a same material with different etching depths. ### Claim 19 (depends on 11) The structure of claim 11, wherein the spirally configured waveguide absorber comprises dielectric material or polysilicon and further comprising a tapered coupler coupling the spirally configured waveguide absorber to the semiconductor waveguide component, wherein the coupler includes a first tapered portion and a second tapered portion of a same material with different etching depths. ### Claim 20 (depends on 11) The structure of claim 11, wherein the Si material is recessed and the Ge material is located within the recess of the Si material.