Optoelectronic device and method of manufacturing thereof

Patent metadata

Field	Value
Publication number	US-10969547-B2
Application number	US-201816619706-A
Country	US
Kind code	B2
Filing date	Jun 7, 2018
Priority date	Jun 9, 2017
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

An optoelectronic device and method of manufacturing the same. The device includes: a layer disposed above a substrate, the layer having a first cavity therein, which cavity is at least partially defined by an inclined interface between the cavity and an insulating liner, the interface being disposed at an angle relative to the substrate of greater than 0° and less than or equal to 90°; and a regrown semiconductor material, providing or forming a part of a waveguide, the regrown semiconductor material being at least partly disposed in the first cavity and including an inclined interface between the regrown semiconductor material and the insulating liner, the interface being disposed at an angle relative to the substrate of greater than 0° and less than or equal to 90°.

First claim

The invention claimed is:

1. An optoelectronic device, including:
a layer disposed above a substrate, the layer having a first cavity therein, which cavity is at least partially defined by an inclined interface between the cavity and an insulating liner, the interface being disposed at an angle relative to the substrate of greater than 0° and less than or equal to 90°;
a regrown semiconductor material, providing or forming a part of a waveguide, the regrown semiconductor material being at least partly disposed in the first cavity and including an inclined interface between the regrown semiconductor material and the insulating liner, the interface being disposed at an angle relative to the substrate of greater than 0° and less than or equal to 90°;
a first doped region of the regrown semiconductor material; and
either a second doped region of the regrown semiconductor material such that the optoelectronic device is operable as an electro-absorption modulator or a photodiode, or
a second doped region of the layer disposed above the substrate such that the optoelectronic device is operable as a MOS-type capacitor.

2. The optoelectronic device of claim 1 , wherein the inclined interfaces are disposed at an angle relative to the substrate of greater than 0° and less than 90°.

3. The optoelectronic device of claim 1 , wherein the angles are as measured in a plane perpendicular to a light guiding direction of the waveguide.

4. The optoelectronic device of claim 1 , wherein the layer disposed above a substrate is formed of silicon, and the regrown semiconductor material is formed of silicon-germanium.

5. The optoelectronic device of claim 4 , further including:
a second cavity of the silicon layer, wherein the second cavity is filled with SiGe.

6. The optoelectronic device of claim 1 , wherein:
the optoelectronic device is an electro-absorption modulator or a photodiode;
the first doped region of the regrown semiconductor material is an N doped region of the regrown semiconductor material;
the second doped region of the regrown semiconductor material is a P doped region of the regrown semiconductor material; and
wherein the N doped region is separated from the P doped region by an undoped region of the regrown semiconductor material.

7. The optoelectronic device of claim 6 , wherein:
the optoelectronic device is operable as an electro-absorption modulator; and
the optoelectronic device further includes a first electrode and second electrode, each extending from an uppermost surface of the optoelectronic device to either the N doped region or the P doped region, wherein the N doped region and P doped region are disposed below the first and second electrodes.

8. The optoelectronic device of claim 7 , further including
an N+ doped region, comprising a part of the N doped region of the regrown semiconductor material, disposed adjacent to the first electrode; and
a P+ doped region, comprising a part of the P doped region of the regrown semiconductor material, disposed adjacent to the second electrode.

9. The optoelectronic device of claim 1 , wherein:
the optoelectronic device is operable as a MOS-type capacitor;
the first doped region of the regrown semiconductor material is adjacent to the interface between the regrown semiconductor material and the insulating liner, and contains a first species of dopant; and
the second doped region of the layer disposed above the substrate is adjacent to the interface between the cavity and the insulating layer, and contains a second species of dopant;
wherein the device further includes:
a first electrode, electrically connected to the first doped region; and
a second electrode electrically connected to the second doped region.

10. The optoelectronic device of claim 9 , further including:
a third doped region of the regrown semiconductor material containing a heavy level of dopants of the first species;
a fourth doped region of the layer above the substrate containing a heavy level of dopants of the second species; wherein:
the first electrode contacts the third doped region; and
the second electrode contacts the fourth doped region.

11. The optoelectronic device of claim 9 , wherein the first doped region of the regrown semiconductor material and the second doped region of the layer above the substrate extend towards an uppermost surface of the device, thereby providing a ridge waveguide.

12. The optoelectronic device of claim 9 , wherein:
the first cavity is further defined by a bed, wherein the insulating layer extends between the bed of the cavity and the regrown semiconductor material.

13. The optoelectronic device of claim 12 , wherein the bed contains dopants of the second species, and a region of the regrown semiconductor material which opposes the bed across the insulating layer contains dopants of the first species.

14. The optoelectronic device of claim 1 , wherein:
the first cavity is further defined by a bed, wherein the insulating layer extends between the bed of the cavity and the regrown semiconductor material; and
a region of the regrown semiconductor material extends away from the bed to thereby provide or form a part of a ridge waveguide.

15. The optoelectronic device of claim 14 , wherein the region of the regrown semiconductor material and the layer above the substrate provide the ridge waveguide, and the insulating layer is positioned at least partially within the ridge waveguide.

16. The optoelectronic device of claim 14 , wherein:
a doped region of the regrown semiconductor material including the ridge waveguide contains dopants of a first species; and
a doped region of the bed opposing the regrown semiconductor material contains dopants of a second species.

17. Optoelectronic device of claim 16 , wherein:
the doped region of the bed extends beyond a width of the ridge waveguide, or a border of the doped region of the bed is aligned with the ridge waveguide.

18. A method of manufacturing an optoelectronic device, the method comprising:
providing a layer above a substrate;
etching in the layer: a first cavity, a second cavity, and a channel connecting the first and second cavity, wherein the first cavity is at least partially defined by a sidewall which is inclined relative to the substrate;
lining the sidewalls of the first cavity with an insulating liner;
depositing a blanket layer to fill the first and second cavity;
depositing an insulating capping layer over the blanket layer;
annealing the optoelectronic device to melt the blanket layer and subsequently cooling, thereby forming a regrown semiconductor material within the first cavity and the second cavity; and
removing the insulating capping layer, and etching the regrown semiconductor material such that it provides or forms a part of a waveguide, the regrown semiconductor material including an inclined interface between the insulating liner and the regrown semiconductor material.

19. The method of claim 18 ,
further including:
doping a first region of the regrown semiconductor material adjacent to the interface between the regrown semiconductor material and the insulating liner with a first species of dopant;
doping a second region of the waveguide with a second species of dopant; and
depositing first and second electrodes which are electrically connected to the first and second regions respectively;
wherein the first and second regions are separated by undoped region of the waveguide, such that the optoelectronic device is an electro-absorption modulator; or

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Assignees

• Univ Southampton

Inventors

• Gardes Frederic Yannick
• Grabska Katarzyna Monika

Classifications

• G02F1/2257

  the optical waveguides being made of semiconducting material · CPC title

• G02B6/136

  by etching · CPC title

• G02B2006/12097

  Ridge, rib or the like · CPC title

• G02F1/0157

  using electro-absorption effects, e.g. Franz-Keldysh [FK] effect or quantum confined stark effect [QCSE] · CPC title

• G02B2006/12085

  Integrated · CPC title