Bias control structure for avalanche photodiodes

Patent metadata

Field	Value
Publication number	US-10797193-B2
Application number	US-201916253475-A
Country	US
Kind code	B2
Filing date	Jan 22, 2019
Priority date	Jan 23, 2018
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

According to some implementations, an avalanche photodiode may include a photon absorbing layer to absorb photons of an optical beam and to provide a response. The avalanche photodiode may include a gain response layer to provide a gain to the response. The avalanche photodiode may include a bias control structure connected to the gain response layer to control an electric field in the photon absorbing layer and the gain response layer.

First claim

What is claimed is:

1. An avalanche photodiode, comprising:
a photon absorbing layer to absorb photons of an optical beam and to provide a response;
a gain response layer to provide a gain to the response; and
a bias control structure connected to the gain response layer to control an electric field in the photon absorbing layer and the gain response layer.

2. The avalanche photodiode of claim 1 , wherein a top portion of the photon absorbing layer is p-doped to form an ohmic contact to receive an anode.

3. The avalanche photodiode of claim 1 , wherein a portion of the gain response layer is p-doped to form a charge medium.

4. The avalanche photodiode of claim 1 , wherein a gain value of the avalanche photodiode is optimized based on a first width of a charge region of the gain response layer and a second width of the photon absorbing layer.

5. The avalanche photodiode of claim 1 , wherein a portion of the gain response layer is n-doped to form an ohmic contact to receive a cathode.

6. The avalanche photodiode of claim 1 , wherein a portion of the gain response layer is p-doped to form an ohmic contact to receive the bias control structure.

7. A photodiode, comprising:
a substrate;
a buffer layer;
a silicon layer, comprising:
a set of p-doped silicon sections, comprising:
a first p-doped silicon section, and
a second p-doped silicon section,

a set of intrinsic silicon sections sandwiching the set of p-doped silicon sections, and
a set of n-doped silicon sections sandwiching the set of intrinsic silicon sections;

a set of germanium layers, comprising:
an intrinsic germanium layer disposed on the set of intrinsic silicon sections and the first p-doped silicon section, and
a p-doped germanium layer disposed on the intrinsic germanium layer;

a set of cathodes disposed on the set of n-doped silicon sections;
an anode disposed on the p-doped germanium layer; and
a bias control structure disposed on the second p-doped silicon section.

8. The photodiode of claim 7 , wherein the set of germanium layers is epitaxially grown on the silicon layer.

9. The photodiode of claim 7 , wherein a total thickness of the set of germanium layers is less than 800 nanometers (nm).

10. The photodiode of claim 7 , further comprising:
a spiral inductor connected to the bias control structure to isolate a radio frequency signal and a direct current signal.

11. The photodiode of claim 7 , further comprising:
a silicon waveguide coupled to the first p-doped silicon section.

12. The photodiode of claim 7 , wherein the anode is to provide a first negative voltage to the intrinsic germanium layer and the bias control structure is to apply a second negative voltage to control an electric field in the intrinsic germanium layer.

13. The photodiode of claim 7 , wherein the anode, the set of cathodes, and the bias control structure are to induce a first electric field in the intrinsic germanium layer and a second electric field in the set of intrinsic silicon sections.

14. The photodiode of claim 13 , wherein the second electric field is greater than the first electric field.

15. The photodiode of claim 7 , further comprising:
a cladding material to enclose the set of cathodes, the anode, the set of germanium layers, and the silicon layer.

16. An optical detector, comprising:
an avalanche photodiode, comprising:
a first layer to absorb photons of an optical beam and to provide a response;
a second layer to provide a gain to the response; and
a bias control structure connected to the first layer to control a first electric field in the first layer and a second electrical field in the second layer; and

a waveguide coupled to the avalanche photodiode to direct the optical beam to the second layer.

17. The optical detector of claim 16 , further comprising an anode and a cathode separate from the bias control structure.

18. The optical detector of claim 16 , wherein the first layer is germanium and the second layer is silicon.

19. The optical detector of claim 16 , wherein the optical detector is a III-V semiconductor optical detector.

20. The optical detector of claim 16 , wherein the avalanche photodiode further comprises:
a substrate,
wherein the substrate is indium-gallium-arsenide (InGaAs) or indium phosphide (InP).

Assignees

• Lumentum Operations Llc

Inventors

• Samani Alireza
• Plant David
• Ayliffe Michael

Classifications

• H10F77/122

  comprising only Group IV materials · CPC title

• H10F30/223

  the potential barrier being a PIN barrier · CPC title

• H10F77/206

  for devices having potential barriers · CPC title

• H10F30/225 Primary

  the potential barrier working in avalanche mode, e.g. avalanche photodiodes · CPC title

• H10F30/2255 Primary

  in which the active layers form heterostructures, e.g. SAM structures · CPC title