# US 2025/0098338 A1 · Silicon photomultiplier tube

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- Number: US 2025/0098338 A1
- Document ID: US20250098338A1
- Status: Published application
- Kind: A1
- Application number: 18/632,404
- Filed: 2024-04-11
- Published: 2025-03-20
- Earliest claimed: 2023-09-15
- Assignees: Shanghai Huali Microelectronics Corporation
- Applicants: Shanghai Huali Microelectronics Corporation
- Inventors: Zhao Guo; Chengdong Liang; Liangliang He
- Web page: https://patentgrep.com/patent/US20250098338A1

## CPC

- H10F 30/225: the potential barrier working in avalanche mode, e.g. avalanche photodiodes
- H10F 77/148: {Shapes of potential barriers}
- H10F 77/206: {for devices having potential barriers}
- H10F 77/241: {comprising ring electrodes}
- H10F 77/959: {for devices working in avalanche mode}
- Y02D 30/70: in wireless communication networks
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

This application discloses a unit structure of a silicon photomultiplier tube, including a first conductive type heavily doped first electrode region located on a first side of the shallow trench isolation, a second conductive type heavily doped second electrode region located on a second side, and a quenching resistor located on a top surface of the shallow trench isolation. A photosensitive layer is formed in the silicon substrate at bottoms of the first electrode region, the shallow trench isolation and the second electrode region. The first electrode region, the photosensitive layer and the second electrode region form a Geiger mode avalanche photodiode. A first end of the quenching resistor is connected to the first electrode region through a first metal interconnect structure. A second end of the quenching resistor is connected to a first electrode. The second electrode region is connected to a second electrode.

## Claims

### Claim 1

A silicon photomultiplier tube, wherein each unit structure comprises:
a silicon substrate;
a shallow trench isolation formed on the silicon substrate;
a first electrode region heavily doped in a first conductive type located on a surface of the silicon substrate on a first side of the shallow trench isolation;
a second electrode region heavily doped in a second conductive type located on a surface of the silicon substrate on a second side of the shallow trench isolation; and
a quenching resistor located on a top surface of the shallow trench isolation,
a photosensitive layer is formed in the silicon substrate at a bottom of the first electrode region,
the first electrode region, the photosensitive layer, and the second electrode region form a Geiger mode avalanche photodiode,
a first end of the quenching resistor is connected to the first electrode region through a first metal interconnect structure,
a second end of the quenching resistor is connected to a first electrode,
the second electrode region is connected to a second electrode,
the first electrode and the second electrode are both located on a front side of the silicon substrate, and photons enter the photosensitive layer from a front side of the first electrode region to achieve photo sensing.

### Claim 2 (depends on 1)

The silicon photomultiplier tube according to claim 1, wherein a silicon epitaxial layer is further formed on the silicon substrate, and the photosensitive layer, the first electrode region, the shallow trench isolation, and the second electrode region are all formed in the silicon epitaxial layer.

### Claim 3 (depends on 2)

The silicon photomultiplier tube according to claim 2, wherein the photosensitive layer comprises a deep photodiode region of the first conductive type;
the first electrode region is located in a surface region of the deep photodiode region;
the deep photodiode region is located in a deep well region of the second conductive type;
a unit well region of the second conductive type is located in the deep well region, and the second electrode region is located in a surface region of the unit well region; and
the deep photodiode region and the unit well region are in contact or have spacing on a bottom side of the shallow trench isolation.

### Claim 4 (depends on 3)

The silicon photomultiplier tube according to claim 3, wherein the first conductive type is N-type, and the second conductive type is P-type; or the first conductive type is P-type, and the second conductive type is N-type.

### Claim 5 (depends on 1)

The silicon photomultiplier tube according to claim 1, wherein the quenching resistor is composed of polysilicon resistors.

### Claim 6 (depends on 1)

The silicon photomultiplier tube according to claim 1, wherein the first metal interconnect structure comprises a first contact formed in a top of the first end of the quenching resistor, a second contact formed in a top of the first electrode region, and a first metal wire connecting the first contact and the second contact.

### Claim 7 (depends on 3)

The silicon photomultiplier tube according to claim 3, wherein the deep photodiode region, the deep well region, and the unit well region are all formed through ion implantation.

### Claim 8 (depends on 4)

The silicon photomultiplier tube according to claim 4, wherein the silicon photomultiplier tube is composed of a plurality of unit structures connected in parallel; and
first electrodes of all unit structures are connected together, and second electrodes of all unit structures are connected together.

### Claim 9 (depends on 8)

The silicon photomultiplier tube according to claim 8, wherein a voltage between the first electrode and the second electrode is tens of volts.

### Claim 10 (depends on 8)

The silicon photomultiplier tube according to claim 8, wherein a number of unit structures connected in parallel in the silicon photomultiplier tube ranges from tens to tens of thousands.

### Claim 11 (depends on 8)

The silicon photomultiplier tube according to claim 8, wherein a resistance of the quenching resistor ranges from tens of Ω to thousands of Ω.