Optoelectronic device

• US 10,401,656 B2
• Filed: 09/27/2018
• Issued: 09/03/2019
• Est. Priority Date: 07/05/2017
• Status: Active Grant

• Current Assignee: Rockley Photonics Limited
• Original Assignee: Rockley Photonics Limited
• Inventors: Yu, Guomin, Abediasl, Hooman, Lerose, Damiana, Nagra, Amit Singh, Srinivasan, Pradeep, Jones, Haydn Frederick
• Primary Examiner(s): Dinh, Jack
• Application Number:
  US16/144,994
• Publication Number:
  US 20190041667A1
• Time in Patent Office: 341 Days
• CPC Class Codes: G01J 1/0425 using optical fibers
• CPC Class Codes: G01J 5/024 Special manufacturing steps or sacrificial layers or layer structures
• CPC Class Codes: G01J 5/0818 Waveguides
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G02B 6/131 by using epitaxial growth epitaxial growth for semiconductors H01L21/02365
• CPC Class Codes: G02B 6/136 by etching
• CPC Class Codes: G02F 1/0102 Constructional details, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/011 in optical waveguides, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence
• CPC Class Codes: G02F 1/225 in an optical waveguide structure
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304
• CPC Class Codes: H10K 39/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic radiation-sensitive element covered by group H10K30/00
• CPC Class Codes: Y02P 80/30 Reducing waste in manufacturing processes; Calculations of released waste quantities

Abstract

An optoelectronic device and method of making the same. The device comprising: a substrate; a regrown cladding layer, on top of the substrate; and an optically active region, above the regrown cladding layer; wherein the regrown cladding layer has a refractive index which is less than a refractive index of the optically active region, such that an optical mode of the optoelectronic device is confined to the optically active region.

Claims

1. A method of manufacturing an optoelectronic device from a silicon-on-insulator wafer comprising a substrate, an insulating layer, and a silicon-on-insulator layer, the method comprising the steps of:

etching a cavity into the wafer, such that a depth of the cavity extends to at least an upper surface of the substrate;

growing a cladding layer onto the upper surface of the substrate;

growing an optically active material onto the cladding layer, wherein the cladding layer has a refractive index which is less than a refractive index of the optically active material; and

etching the optically active material so as to form an optically active region above the cladding layer.

2. The method of claim 1, wherein the step of etching a cavity into the wafer comprises:

a first etching step, where the insulating layer is used as an etch-stop; and

a second etching step, where the substrate is used as an etch-stop.

3. The method of claim 1, further including a step after etching the cavity and before growing the cladding layer of:

coating sidewalls of the cavity with an insulator.

4. The method of claim 1, further including a step after growing the optically active material of:

planarizing the grown optically active material.

5. The method of claim 1, further including a step, after growing the optically active material and before etching the optically active material, of:

disposing a hard mask on top of at least a part of the grown optically active material.

6. The method of claim 1, further including a step, after etching the optically active material, of:

doping the optically active region with dopants of a first and second species, so as to provide an electro-absorption modulator.

7. The method of claim 1, wherein the cladding layer is an epitaxially grown silicon or silicon germanium layer.

8. The method of claim 1, further including a step, after growing the cladding layer, of growing a seed layer on top of the cladding layer.

9. The method of claim 1, wherein the optically active material is grown through blanket deposition.

10. The method of claim 1, wherein the optically active material is etched to provide a waveguide structure for an electro-absorption modulator or a photodiode.

11. The method of claim 1, wherein the optically active region is formed of Si_xGe_1-x-ySn_y, where 5%≤

x≤

20%, 1%≤

y≤

10%.

12. The method of claim 1, wherein the optically active region comprises a silicon-germanium region.

13. The method of claim 1, wherein the optically active region is grown from SiGe or SiGeSn having a first composition, and the cladding layer is grown from SiGe or SiGeSn having a second composition different from the first composition.

14. The method of claim 1, wherein the optically active material comprises a material selected from the group consisting of SiGeSn, GeSn, InGaNAs, and InGaNAsSb.