Monolithic silicon photomultiplier array

Patent metadata

Field	Value
Publication number	US-12155000-B2
Application number	US-202117475010-A
Country	US
Kind code	B2
Filing date	Sep 14, 2021
Priority date	Sep 20, 2019
Publication date	Nov 26, 2024
Grant date	Nov 26, 2024

Abstract

An optical system may include a substrate and a plurality of silicon photomultipliers (SiPMs) monolithically integrated with the substrate. Each SiPM may include a plurality of single photon avalanche diodes (SPADs). The optical system also includes an aperture array having a plurality of apertures. The plurality of SiPMs and the aperture array are aligned so as to define a plurality of receiver channels. Each receiver channel includes a respective SiPM of the plurality of SiPMs optically coupled to a respective aperture of the plurality of apertures.

First claim

What is claimed is:

1. An optical system comprising:
a substrate;
a plurality of light-detecting elements monolithically integrated with the substrate, wherein each light-detecting element comprises a plurality of detectors;
an aperture array comprising a plurality of apertures, wherein the plurality of light-detecting elements and the aperture array are aligned so as to define a plurality of receiver channels, wherein each receiver channel comprises a respective light-detecting element of the plurality of light-detecting elements optically coupled to a respective aperture of the plurality of apertures; and
a baffle structure, wherein the baffle structure comprises a plurality of openings in an optically opaque material, wherein the baffle structure is arranged between the aperture array and the plurality of light-detecting elements such that each receiver channel comprises a respective light-detecting element of the plurality of light-detecting elements optically coupled to a respective aperture of the plurality of apertures via a respective opening in the baffle structure.

2. The optical system of claim 1 , wherein the substrate comprises a silicon wafer, an indium phosphide wafer, or a gallium arsenide wafer.

3. The optical system of claim 1 , wherein each light-detecting element of the plurality of light-detecting elements comprises at least 1000 detectors.

4. The optical system of claim 1 , wherein the plurality of light-detecting elements are arranged along the substrate in a hexagonal or square array.

5. The optical system of claim 1 , wherein the plurality of light-detecting elements are arranged along the substrate with a density of about 0.4 light-detecting elements per mm 2 .

6. The optical system of claim 1 , further comprising a plurality of electrical conductors, wherein the plurality of electrical conductors is coupled to the plurality of light-detecting elements via at least one of: a through substrate via (TSV) or a side routing arrangement.

7. The optical system of claim 1 , further comprising at least one isolation trench in the substrate, wherein the at least one isolation trench is arranged between neighboring light-detecting elements.

8. The optical system of claim 7 , wherein the at least one isolation trench is at least partially filled with at least one of: a metal material, an optically-opaque material, a conductive material, or a non-conductive material.

9. The optical system of claim 7 , wherein the at least one isolation trench provides electrical isolation or optical isolation between the neighboring light-detecting elements.

10. The optical system of claim 1 , further comprising a plurality of optical waveguides, wherein each optical waveguide is configured to couple light into a respective light-detecting element of the plurality of light-detecting elements.

11. The optical system of claim 1 , wherein a cross-section of the baffle structure comprises a plurality of diamond-shaped members separated by the respective openings in the baffle structure.

12. A method of manufacturing an optical system, the method comprising:
providing a monolithic light-detecting element array comprising a plurality of light-detecting elements monolithically integrated with a substrate, wherein each light-detecting element comprises a plurality of detectors;
aligning an aperture array comprising a plurality of apertures with the monolithic light-detecting element array so as to define a plurality of receiver channels, wherein each receiver channel comprises a respective light-detecting element of the plurality of light-detecting elements optically coupled to a respective aperture of the plurality of apertures; and
positioning a baffle structure comprising a plurality of openings in an optically opaque material between the monolithic light-detecting element array and the aperture array such that each receiver channel comprises a respective light-detecting element of the plurality of light-detecting elements optically coupled to a respective aperture of the plurality of apertures via a respective opening in the baffle structure.

13. The method of claim 12 , wherein the plurality of light-detecting elements in the monolithic light-detecting element array are arranged in a hexagonal or square array.

14. The method of claim 12 , wherein the plurality of light-detecting elements in the monolithic light-detecting element array are arranged with a density of about 0.4 light-detecting elements per mm 2 .

15. The method of claim 12 , wherein the monolithic light-detecting element array further comprises at least one isolation trench in the substrate, wherein the at least one isolation trench is arranged between neighboring light-detecting elements.

16. The method of claim 15 , wherein the at least one isolation trench is at least partially filled with at least one of: a metal material, an optically-opaque material, a conductive material, or a non-conductive material.

17. The method of claim 15 , wherein the at least one isolation trench provides electrical isolation between the neighboring light-detecting elements.

18. The method of claim 15 , wherein the at least one isolation trench provides optical isolation between the neighboring light-detecting elements.

Assignees

• Waymo Llc

Inventors

• Onal Caner
• Droz Pierre-Yves
• Dharia Nirav

Classifications

• G01S7/4816 Primary

  of receivers alone · CPC title

• H10F77/413

  directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42) · CPC title

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F39/103 Primary

  the at least one element covered by H10F30/00 having potential barriers, e.g. integrated devices comprising photodiodes or phototransistors · CPC title

• H10F30/225 Primary

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