CN115148753A

CN115148753A - Photodiode array, preparation method, sensor, camera and electronic equipment

Info

Publication number: CN115148753A
Application number: CN202210763731.6A
Authority: CN
Inventors: 祁春超; 李玉鹏; 刘艳丽
Original assignee: Hangzhou Hikvision Digital Technology Co Ltd
Current assignee: Hangzhou Hikvision Digital Technology Co Ltd
Priority date: 2022-06-30
Filing date: 2022-06-30
Publication date: 2022-10-04

Abstract

The embodiment of the application provides a photodiode array, a preparation method, a sensor, a camera and electronic equipment. The photodiode array includes a semiconductor substrate, a plurality of photodiodes, and a plurality of light-scattering members. The photodiodes are arranged in the semiconductor substrate and distributed in an array mode, and each photodiode is provided with a light sensing surface and a backlight surface. The plurality of light scattering pieces are arranged on one side, close to the photosensitive surface, of the semiconductor substrate, each light scattering piece comprises at least one scattering lens, each scattering lens is provided with a convex surface, the convex surface faces the photosensitive surface of the corresponding photodiode, and the scattering lenses are used for scattering light penetrating through the scattering lenses. According to the photodiode array, light is scattered through the convex surface of the scattering lens and is dispersed into a plurality of directions to be transmitted to the photosensitive surface of the photodiode, so that the light quantity transmitted out of the semiconductor substrate can be reduced, the transmission path of the light is prolonged, and the absorption of the photodiode to the light is facilitated, so that the quantum efficiency is improved.

Description

Photodiode array, preparation method, sensor, camera and electronic equipment

Technical Field

The application relates to the technical field of semiconductors, in particular to a photodiode array, a preparation method, a sensor, a camera and electronic equipment.

Background

There is an increasing demand for Near Infrared (NIR) image sensors for iris verification, face recognition and dynamic capture. However, the quantum efficiency of the conventional image sensor in the NIR band is low (about 850nm 10% or 940nm 4% or so) because the wavelength of the near infrared light is long (700-1000). The photodiode serves as a light sensing element in the image sensor. In order to improve the quantum efficiency of the image sensor in the NIR band, it is necessary to improve the quantum efficiency of the photodiode to near infrared light. The conventional method is to increase the thickness of the incident photon absorption layer, i.e. increase the thickness of the photodiode, which results in a larger thickness of the image sensor and is difficult to implement.

Disclosure of Invention

The embodiment of the application provides a photodiode array, a preparation method, a sensor, a camera and electronic equipment, which are used for improving the quantum efficiency of the photodiode array to near infrared light.

In order to achieve the purpose, the technical scheme is as follows:

in a first aspect of the embodiments of the present application, a photodiode array is provided, which includes a semiconductor substrate, a plurality of photodiodes, and a plurality of light-scattering members. The photodiodes are arranged in the semiconductor substrate and distributed in an array mode, and each photodiode is provided with a light sensing surface and a backlight surface. The plurality of light scattering members are arranged on one side, close to the photosensitive surface, of the semiconductor substrate, correspond to the plurality of photodiodes one to one, and are used for scattering light penetrating through the light scattering members.

According to the photodiode array, light is scattered through the light scattering piece and is scattered into a plurality of directions to be transmitted to the photosensitive surface of the photodiode, so that the light quantity transmitted out of the semiconductor substrate can be reduced, the transmission path of the light is prolonged, the area of the photosensitive surface of the photodiode, which can actually receive the light, is enlarged, the absorption of the photodiode to the light is facilitated, and the quantum efficiency is improved.

Optionally, each light scattering member includes at least one scattering lens having a convex surface facing the photosensitive surface of the corresponding photodiode of the scattering lens, and the scattering lens is configured to scatter light transmitted through the scattering lens. According to the photodiode array, light is scattered through the convex surface of the scattering lens and is dispersed into a plurality of directions to be transmitted to the photosensitive surface of the photodiode, so that the light quantity transmitted out of the semiconductor substrate can be reduced, the transmission path of the light is prolonged, the area of the photosensitive surface of the photodiode, which can actually receive the light, is enlarged, the absorption of the photodiode to the light is facilitated, and the quantum efficiency is improved.

Optionally, a vertical projection of the scattering lens on the semiconductor substrate overlaps a vertical projection of the photodiode on the semiconductor substrate. Thus, the scattering lens is at least partially arranged in the light-sensitive surface of the photodiode, and is beneficial to the absorption of the photodiode to light, thereby improving the quantum efficiency.

Optionally, in any of the light diffusers, the diffuser lens includes at least one first diffuser lens and at least one second diffuser lens, and a radius of a convex surface of the first diffuser lens is smaller than a radius of a convex surface of the second diffuser lens. Like this, the cooperation of the first scattering lens and the second scattering lens of the radius of different convex surfaces for the propagation direction of light further diverges, and light is more dispersed, and its propagation path also more prolongs, thereby it improves quantum efficiency to be favorable to the absorption of photodiode to light more.

Optionally, the at least one first scattering lens and the at least one second scattering lens are arranged in a line to form a lens unit. The lens units are distributed in an array mode or distributed in a crossed mode. Therefore, the scattering lenses are regularly distributed, and the scattering of the light of the scattering unit can be adjusted by setting the number and arrangement mode of the scattering lenses in the lens unit, so that the lens unit can be used to adapt to different requirements.

Alternatively, in one lens unit, one first diffusion lens and one second diffusion lens are alternately arranged. The lens unit structure is simple, and the manufacturing difficulty is reduced.

Optionally, in any one of the diffusers, edges of adjacent two scattering lenses contact or partially overlap. The scattering lens of this kind of mode is more nimble, adaptable different demands.

Optionally, the light dispersion member has a first region and a second region surrounding the first region. At least one scattering lens in the light scattering member includes N third scattering lenses and M fourth scattering lenses. The third scattering lens is located in the first region, and the fourth scattering lens is located in the second region. Wherein N > M, and both N and M are positive integers. Therefore, the requirements of scattering light and improving the quantum efficiency are met, and the number of scattering lenses can be reduced, so that the production cost of the light-scattering piece is reduced. In addition, the number of the scattering lenses in the edge area of the light scattering piece is small, and the manufacturing difficulty of the light scattering piece is reduced.

Optionally, the radius of the convex surface comprises 0.5 to 1 micron. The convex scattering lens with the radius can effectively scatter light, so that the light is further diffused in the propagation direction, the light is more dispersed, the propagation path of the light is more prolonged, and the light is more favorably absorbed by the photodiode, so that the quantum efficiency is improved.

Optionally, the photodiode array further comprises a plurality of isolation trenches and a first scattering structure. The isolation channels are arranged in the semiconductor substrate and extend along the direction from the light sensing surfaces of the photodiodes to the backlight surface. The isolation channel is disposed around a perimeter of the photodiodes, separating adjacent photodiodes. The first scattering structure is arranged on the side face, facing the photodiode, of the isolation channel. The first scattering structure is used for scattering light incident to the isolation channel to the photodiode, so that the absorption of the photodiode to the light can be facilitated, and the quantum efficiency can be improved.

Optionally, the photodiode array further comprises a plurality of metal grids. The metal grids are arranged in the semiconductor substrate and are positioned at the end parts of the isolation channels, which are close to the light-sensitive surfaces of the photodiodes. Therefore, the electric signal generated by the photodiode can be prevented from being transmitted to the adjacent photodiode to generate electric crosstalk. Thus, the photodiode array is more sensitive.

Optionally, the photodiode array further includes a second scattering structure disposed on a side of the semiconductor substrate close to the backlight surface, and the second scattering structure is configured to scatter light incident on the backlight surface of the photodiode to the photodiode. Thus, the absorption of light by the photodiode can be facilitated, and the quantum efficiency can be improved.

In a second aspect of the embodiments of the present application, there is provided a method for manufacturing a photodiode array, the method including:

forming a plurality of photodiodes distributed in an array in a semiconductor substrate; wherein the photodiode has a light sensing surface and a backlight surface.

A plurality of light scattering members are formed in the semiconductor substrate on the side close to the photosensitive surface, the plurality of light scattering members correspond to the plurality of photodiodes one to one, and the light scattering members are used for scattering light penetrating through the light scattering members.

The method of the photodiode array includes a light-scattering element, and thus has the same effect and function as the photodiode array, and is not described in detail.

Optionally, before forming the plurality of light scattering members in the semiconductor substrate on a side close to the photosensitive surface, the method includes: a plurality of arc-shaped grooves are formed on the surface of one side, close to the photosensitive surface, of the semiconductor substrate.

Forming a plurality of light scattering members in the semiconductor substrate on a side adjacent to the photosensitive surface includes: a scattering lens is formed in an arc-shaped groove, the surface of the scattering lens, facing the arc-shaped groove, is an arc surface, the radian of the arc surface is the same as that of the arc surface of the arc-shaped groove, and at least one scattering lens forms a light scattering part.

Optionally, the forming a plurality of arc-shaped grooves on a side surface of the semiconductor substrate close to the photosensitive surface includes: an isotropic etching process is adopted, and the etching process is carried out, A plurality of arc-shaped grooves are formed on the surface of one side, close to the photosensitive surface, of the semiconductor substrate.

In a third aspect of embodiments of the present application, there is provided a sensor, including: lens layer, dielectric layer and above-mentioned photodiode array. The photodiode array, the dielectric layer and the lens layer are sequentially stacked. Since the photodiode array comprises a lens assembly, the quantum efficiency of the sensor to infrared light is high.

Optionally, the dielectric layer and the scattering lens of the photodiode array are connected into an integral structure and made of the same material. Therefore, the manufacturing process of the dielectric layer is simpler, and the matching process of the dielectric layer and the photodiode array is also simpler.

In a fourth aspect of the embodiments of the present application, a camera is provided, which includes a lens assembly and the sensor, where the sensor is disposed on a light-emitting side of the lens assembly. Due to the adoption of the sensor, the imaging quality of the camera is high.

In a fifth aspect of the embodiments of the present application, an electronic device is provided, which includes a housing and the above-mentioned camera, and at least part of the camera is embedded in the housing. Due to the adoption of the camera, image acquisition can be better realized.

Optionally, the electronic device further includes an emitting end, the emitting end is configured to emit the detection light to the object to be detected, and the camera is configured to receive the reflected light of the detection light reflected by the object to be detected. Thus, the electronic equipment can effectively detect the object, such as a processed product.

Drawings

FIG. 1a is a schematic diagram of an embodiment of the present application a schematic structural diagram of an electronic device;

FIG. 1b is a schematic cross-sectional view taken along line D-D of FIG. 1 a;

FIG. 1c is a schematic structural diagram of a sensor provided in an embodiment of the present application;

FIG. 2a is a schematic cross-sectional view along direction E-E of FIG. 1 c;

FIG. 2b is a schematic structural diagram of another sensor provided in the embodiments of the present application;

FIG. 2c is a schematic structural diagram of another sensor provided in the embodiments of the present application;

fig. 3 is a schematic structural diagram of a photodiode array according to an embodiment of the present application;

FIG. 4 is a schematic view of the lens assembly of FIG. 3 mated with a semiconductor substrate;

FIG. 5 is a diagram illustrating a distribution of positions of a diffuser lens with respect to a corresponding photosensitive surface according to an embodiment of the present disclosure;

FIG. 6a is a diagram illustrating a distribution of positions of a diffuser lens with respect to a photosensitive surface according to another embodiment of the present disclosure;

FIG. 6b is a schematic structural diagram of a lens unit according to an embodiment of the present disclosure;

FIG. 6c is a schematic structural diagram of a lens unit according to another embodiment of the present application;

FIG. 6d is a schematic diagram of a lens unit according to another embodiment of the present application;

FIG. 6e is a schematic structural diagram of a lens unit according to another embodiment of the present application;

FIG. 6f is a diagram illustrating a distribution of positions of a diffuser lens with respect to a photosensitive surface according to another embodiment of the present disclosure;

FIG. 7a is a schematic diagram illustrating a positional relationship between adjacent scattering lenses according to an embodiment of the present disclosure;

FIG. 7b is a schematic diagram illustrating a positional relationship between adjacent scattering lenses according to another embodiment of the present disclosure;

FIG. 8 is a diagram illustrating a distribution of positions of a diffuser lens with respect to a photosensitive surface according to an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of a photodiode array according to another embodiment of the present application;

FIG. 10a is a simulation result of the absorption efficiency of the photodiode array model 1 for different wavelengths of light;

FIG. 10b is a simulation result of the absorption efficiency of the photodiode array model 2 for different wavelengths of light;

FIG. 10c is a simulation result of the absorption efficiency of the photodiode array model 3 for different wavelengths of light;

FIG. 10d is a simulation result of the absorption efficiency of the photodiode array model 4 for different wavelengths of light;

fig. 10e is a simulation result of the absorption efficiency of the photodiode array model 5 for different wavelengths of light.

Fig. 11 is a flowchart of a method for manufacturing a photodiode array according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments.

In the following, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

Further, in the present application, directional terms such as "upper", "lower", and the like may include, but are not limited to, being defined relative to a schematically-disposed orientation of components in the drawings, it being understood that these directional terms may be relative concepts that are intended for relative description and clarification, and that will vary accordingly depending on the orientation of the components in the drawings in which they are disposed.

In this application, unless expressly stated or limited otherwise, the term "coupled" is to be construed broadly, e.g., "coupled" may be a fixed connection or a releasable connection or may be integral; may be directly connected or indirectly connected through an intermediate. Furthermore, the term "coupled" may be a manner of making electrical connections that communicate signals. "coupled" may be a direct electrical connection or an indirect electrical connection through intervening media.

In some embodiments of the present application, the electronic device may be a mobile phone or a tablet computer, and the electronic device may acquire an image. In this case, the electronic apparatus may include a housing and a camera. The electronic equipment can receive ambient light incident from the outside through the camera and perform photoelectric conversion, and in addition, the electronic equipment can also generate image signals according to the converted electric signals so as to realize image acquisition, such as finishing operations of recording videos, photographing and the like.

In other embodiments, the electronic device may also be a security inspection machine as shown in fig. 1 a. In this case, the electronic apparatus 01 described above mainly includes a housing 02, a camera 03, and a transmitting terminal 04. The transmitting end 04 is used for transmitting the detection light S1 to the object to be detected, and the camera 03 can be used as a receiving end and used for receiving the reflection light S2 of the detection light after being reflected by the object to be detected.

The emitting end 04 emits a detection light S1, such as an infrared ray or an X-ray, to the object to be detected, and after the detection light S1 irradiates the object to be detected, the detection light may be shielded, absorbed, or the intensity and angle of reflection may change by the object to be detected, so as to form a reflection light S2. The camera 03 receives the reflected light S2, and generates different electrical signals to form an image according to the difference in intensity and angle of the reflected light S2, thereby realizing detection of the object to be detected. The electronic device 01 can effectively detect objects, such as processed products, or subway and high-speed rail baggage detection.

Referring to fig. 1b, the camera 03 may comprise a lens assembly 05 and a sensor 06, the sensor 06 being arranged on the light exit side of the lens assembly 05. The light-diffusing member 05 can be made of an optically transparent material such as glass or resin. The lens assembly 05 may comprise one or several lenses. The lens assembly 05 has one or more curved surfaces to change the propagation direction of light on the light exit side and adjust the light distribution to converge the light. The sensor 06 is disposed on the light emitting side of the lens assembly 05, and receives the light collected by the lens assembly 05 to perform imaging.

A sensor 06 as shown in fig. 1c may be used, the sensor 06 comprising a lens layer 30, a dielectric layer 50 and a photodiode array 10.

Referring to fig. 2a, the photodiode array 10 includes a plurality of photodiodes 200 distributed in an array. The photodiodes 200 have a light-sensing surface 200a and a backlight surface 200b, and the light-sensing surface 200a is used for receiving incident light, so that each photodiode 200 can serve as a light-sensing element. The lens layer 30 focuses incident light through the dielectric layer 50 to the photodiode array 10. Specifically, the lens layer 30 generally includes a plurality of microlenses 31, and one microlens 31 covers over the light-sensing surface 200a of one or more photodiodes 200 in the photodiode array 10. The microlenses 31 are mostly convex lenses, and the convex surfaces 320 of the convex lenses are far away from the photodiode array 10, so that incident light incident on the surfaces of the convex lenses is focused and passes through the dielectric layer 50 to reach the photosensitive surfaces 200a of the corresponding photodiodes 200, and the scattering of the incident light can be reduced or avoided due to the focusing effect of the convex lenses on the incident light, so that the quantum efficiency of the photodiodes 200 can be improved. It is understood that the lens layer 30 may be made of a transparent material having a high light transmittance, such as resin.

The dielectric layer 50 is located between the lens layer 30 and the photodiode array 10, and one of the main functions of the dielectric layer 50 is to reduce the amount of incident light reflected off the surface of the photodiode array 10, thereby improving the photoelectric energy conversion efficiency and increasing the quantum efficiency. The material of the dielectric layer 50 may be tantalum oxide, aluminum oxide, hafnium oxide, nitrogen oxide, or an organic material having a refractive index of 1.4-3.8. After the incident light is focused and reaches the surface of the photodiode array 10, part of the incident light is reflected and projected to the dielectric layer 50. Because the refractive index of the dielectric layer 50 is relatively large, part of the light projected to the dielectric layer 50 is totally reflected and refracted back to the surface of the photodiode array 10, thereby reducing the reflection loss of the incident light on the surface of the photodiode array 10.

The photodiode array 10 is disposed under the dielectric layer 50, and includes a plurality of photodiodes 200 arranged in an array. Each photodiode 200, dielectric layer 50 and microlens 31 constitute a light-sensitive pixel 061 in one sensor 06. The sensor 06 can convert an optical signal incident on the above photodiode array 10 into an electrical signal using the photoelectric conversion function of the photodiode array 10. Each photodiode 200 may serve as a photosensitive element for photosensitive pixels 061, wherein the electrical signal generated by each photodiode 200 may be proportional to the optical signal. For example, the electrical signal may be proportional or approximately proportional to the optical signal. Specifically, when the light signal incident on the photodiode 200 is large, if the incident light is strong, the electrical signal output by the photosensitive pixel 061 where the photodiode 200 is located has a large current, for example, and conversely, the current is small. The above description is given by taking an example that the electrical signal may be proportional to the optical signal, and certainly, the electrical signal may also be inversely proportional or approximately inversely proportional to the optical signal, which is not described herein again.

In addition, referring to fig. 2b, the sensor 06 may further include a color filter layer 20 and a metal line layer 40. A color filter layer 20 may be disposed between the lens layer 30 and the media layer 50 when the sensor 06 is required to capture color images. As can be seen from the above, the photodiode array 10 has a plurality of photodiodes 200 arranged in an array, the color filter layer 20 is also provided with a plurality of color filters 21 arranged in an array, and the lens layer 30 is also provided with a plurality of microlenses 31 arranged in an array. Each of the photosensitive pixels 061 has the microlens 31, the color filter 21, and the photodiode 200 stacked in a one-to-one correspondence, and each of the photosensitive pixels 061 is connected to the metal wiring layer 40. Wherein the color filter 21 is positioned between the microlens 31 and the photodiode 200. The microlens 31 gathers incident light to the photodiode 200 via the color filter 21. Each color filter 21 allows only light of a specific wavelength to pass through, and thus the corresponding photodiode 200 obtains different light intensity information, and the original color can be restored by color calculation. The sensor 06 of fig. 2a is a backside illuminated sensor 06. I.e., the photodiode array 10 is located above the metal line layer 40, closer to the color filter layer 20. The sensor 06 may also be a front illuminated sensor 06, as shown in fig. 2c, with the photodiode array 10 below the metal wiring layer 40, away from the color filter layer 20. The rest of the structure is similar to the backside illuminated sensor 06 and is not described in detail. Further, the sensor 06 may be a CCD (Charge coupled device) sensor 06 or a CMOS (Complementary Metal Oxide Semiconductor) sensor 06.

Alternatively, the surface of the dielectric layer 50 adjacent to the photosensitive surface 200a of the photodiode 200 may have a convex 320 structure.

The convex surface 320 is configured to face the light-sensing surface 200a of the photodiode 200. The convex surface 320 has a scattering effect, in which incident light is scattered, and the propagation direction of the incident light is changed from a single direction to an isotropic scattering, so that the amount of light vertically propagating through the photodiode 200 can be reduced. And the light is propagated in all directions, has a certain angle relative to the vertical direction, and the propagation path is prolonged, so that the photodiode 200 can absorb the light conveniently. The convex surface 320 of the dielectric layer 50 and the other parts of the dielectric layer 50 are of an integral structure and made of the same material. Thus, the manufacturing process of the dielectric layer 50 is simpler, and the matching process of the dielectric layer 50 and the photodiode array 10 is also simpler.

The absorption capacity of the photodiode array 10 for light influences the quantum efficiency of the sensor 06 to a large extent. The absorption capability of incident light is directly related to the thickness of the photon absorption layer of the semiconductor substrate 100 of the photodiode array 10. Near infrared light, which is long in wavelength, generally directly penetrates the thin semiconductor substrate 100, resulting in near infrared light loss and a decrease in quantum efficiency. It is therefore an aspect of the present application to provide a photodiode array 10 that can improve quantum efficiency for near infrared light.

The photodiode array 10 according to the embodiment of the present application, referring to fig. 3, includes a semiconductor substrate 100, a plurality of photodiodes 200, and a plurality of light-scattering members 300. The photodiodes 200 are disposed in the semiconductor substrate 100 and distributed in an array, and the photodiodes 200 have a light-sensing surface 200a and a backlight surface 200b. The light-scattering members 300 are disposed on a side of the semiconductor substrate 100 close to the light-sensing surface 200a and correspond to the photodiodes 200 one by one, each light-scattering member 300 includes at least one scattering lens 310, the scattering lens 310 has a convex surface 320, the convex surface 320 faces the light-sensing surface 200a of the photodiode 200 corresponding to the scattering lens 310, and the scattering lens 310 is configured to scatter light transmitted through the scattering lens 310.

Referring to fig. 3, a plurality of photodiodes 200 and a plurality of light-scattering members 300 are provided in a semiconductor substrate 100. The semiconductor substrate 100 includes a first surface 100a and a second surface 100b. For convenience of description, the photodiode 200 is disposed in the semiconductor substrate 100 and near the first surface 100 a. The photodiode 200 has a light-sensing surface 200a and a backlight surface 200b, wherein the surface of the photodiode 200 close to or disposed on the first surface 100a is the light-sensing surface 200a. A light-diffusing member 300 is disposed in the semiconductor substrate 100 near the photosensitive surface 200a, that is, the side of the semiconductor substrate 100 close to the first surface 100a, that is, the light dispersion member 300 is disposed above the photodiode 200.

Referring to fig. 3, the light scattering members 300 and the photodiodes 200 are correspondingly arranged one-to-one, and each light scattering member 300 includes at least one scattering lens 310, it is to be understood that this does not mean that the number and arrangement of the scattering lenses 310 in the light scattering member 300 corresponding to each photodiode 200 are necessarily the same. Each scattering lens 310 has a convex surface 320, and the convex surface 320 faces the light-sensing surface 200a of the photodiode 200 corresponding to the scattering lens 310. In order to reduce the distance between the convex surface 320 of the scattering lens 310 and the photosensitive surface 200a of the photodiode 200, an arc-shaped groove 210 matching with the convex surface 320 of the scattering lens 310 may be disposed on the first surface 110a of the semiconductor substrate 100, so that the convex surface 320 of the scattering lens 310 can be closely attached to the photosensitive surface 200a of the photodiode 200. From the viewpoint of the light dispersion member 300, it can be understood that at least one convex lens is disposed on the light-sensing surface 200a of the photodiode 200. Of course, it can be understood that the light sensing surface 200a of the photodiode 200 has a concave lens when viewed from the perspective of the photodiode 200.

The material of the scattering lens 310 is different from that of the photodiode 200, and the material of the scattering lens 310 may be an oxide such as tantalum oxide, aluminum oxide, hafnium oxide, or nitrogen oxide, or an organic material having a refractive index of 1.4 to 3.8. The material of the photodiode 200 is mainly silicon. Thus, the refractive indices of the two major components are different. Thus, even if the convex surface 320 of the diffusion lens 310 and the light-receiving surface 200a of the photodiode 200 are closely attached to each other, light propagates between media having different refractive indices when propagating through the junction surface between the convex surface 320 of the diffusion lens 310 and the light-receiving surface 200a of the photodiode 200. Otherwise, the refractive indexes are the same, and the scattering effect of the convex surface 320 of the scattering lens 310 disappears. The diffuser lens 310 may be conveniently formed by molding the arc-shaped groove 210 of the photodiode 200 such that the diffuser lens 310 has the convex surface 320.

Referring to fig. 4, the diffusion lens 310 has two surfaces, one surface is a surface having a convex surface 320, and the other surface is an opposite surface of the surface, named a third surface 330. The third surface 330 may be a flat surface. Referring to fig. 3, after light enters the scattering lens 310 from the third surface 330 through the micro lens 31 and the dielectric layer 50, or light directly enters the scattering lens 310 from the third surface 330, the light is scattered by the convex surface 320, so that light with a single propagation direction is dispersed into a plurality of directions to propagate toward the photosensitive surface 200a of the photodiode 200. However, if light is vertically irradiated onto the light-sensing surface 200a of the photodiode 200, refraction does not occur, the propagation path thereof in the photodiode 200 is short, and most of the light is directly transmitted through the semiconductor substrate 100 and cannot be absorbed, so that the quantum efficiency is low. The light propagating in multiple directions reduces the amount of light that is originally vertically irradiated on the light-sensing surface 200a of the photodiode 200, thereby reducing light waste, and most of the light obliquely incident on the light-sensing surface 200a of the photodiode 200 may be refracted, and the propagation path thereof is extended, which is advantageous for the photodiode 200 to absorb the light, thereby improving quantum efficiency. In addition, after the light is dispersed and propagated in multiple directions, the area of the light-sensing surface 200a of the photodiode 200 that can actually receive the light is enlarged, which is also beneficial to the absorption of the light by the photodiode 200, thereby improving the quantum efficiency.

In the photodiode array 10, light is scattered by the convex surface 320 of the scattering lens 310 and is dispersed in a plurality of directions to propagate toward the light-sensing surface 200a of the photodiode 200, so that the amount of light transmitted from the semiconductor substrate 100 can be reduced, the propagation path of light can be extended, the area of the light-sensing surface 200a of the photodiode 200 that can actually receive light can be enlarged, and the absorption of light by the photodiode 200 is facilitated, thereby improving the quantum efficiency.

Alternatively, referring to fig. 3, a vertical projection of the diffusion lens 310 on the semiconductor substrate 100 overlaps with a vertical projection of the photodiode 200 on the semiconductor substrate 100. Thus, the diffusion lens 310 is at least partially disposed in the light-sensing surface 200a of the photodiode 200, and after light is diffused by the convex surface 320 of the diffusion lens 310, a relatively large amount of light can enter the light-sensing surface 200a of the photodiode 200, which is beneficial for the photodiode 200 to absorb light, thereby improving quantum efficiency.

Optionally, referring to fig. 5, in any of the light diffusers 300, the diffuser lens 310 includes at least one first diffuser lens 311 and at least one second diffuser lens 312, and a radius of a convex surface 320 of the first diffuser lens 311 is smaller than a radius of a convex surface 320 of the second diffuser lens 312.

The diffusion lens 310 has different specifications including a first diffusion lens 311 and a second diffusion lens 312. The number of the first diffusion lens 311 and the second diffusion lens 312 is not limited. The radius of the convex surface 320 of the first scattering lens 311 is smaller than the radius of the convex surface 320 of the second scattering lens 312. The first scattering lens 311 and the second scattering lens 312 with the convex surfaces 320 with different radii are mixed and matched, so that part of light scattered by the convex surface 320 of the first scattering lens 311 is transmitted to the surface of the convex surface 320 of the second scattering lens 312 to be scattered for the second time, the transmission direction of the light is further diverged, the light is more dispersed, the transmission path of the light is more prolonged, and the light is more favorably absorbed by the photodiode 200, so that the quantum efficiency is improved.

Alternatively, referring to fig. 6a, at least one first diffusion lens 311 and at least one second diffusion lens 312 are aligned to form a lens unit 340. The lens units 340 are distributed in an array or the lens units 340 are distributed across.

Each lens unit 340 includes both the first diffusion lens 311 and the second diffusion lens 312 therein. In the lens unit 340, various matching manners may be adopted, such as matching a first diffusion lens 311 with a second diffusion lens 312, matching a first diffusion lens 311 with several second diffusion lenses 312 (refer to fig. 6b, matching an exemplary 1 first diffusion lens 311 with 2 second diffusion lenses 312), matching several first diffusion lenses 311 with a second diffusion lens 312 (refer to fig. 6c, matching an exemplary 2 first diffusion lenses 311 with 1 second diffusion lens 312), and matching several first diffusion lenses 311 with several second diffusion lenses 312 (refer to fig. 6d, matching an exemplary 3 first diffusion lenses 311 with 2 second diffusion lenses 312). Of course, the lens unit 340 including the determined number of first diffusion lenses 311 and the determined number of second diffusion lenses 312 also has various arrangements, and the specific arrangement is not limited herein. For example, the lens unit 340 includes 2

first diffusion lenses

311 and 2 second diffusion lenses 312, including at least two ways of fig. 6d and 6 e.

The lens units 340 may be distributed in an array, for example, according to the shape of the light-sensing surface 200a of the photodiode 200, and referring to fig. 6a, for example, the light-sensing surface 200a of the photodiode 200 is rectangular, and the lens units 340 may be arranged in three rows and three columns, that is, 3 × 3, on the plane where the light-sensing surface 200a of the photodiode 200 is located. The lens units 340 may also be distributed in a crossed manner, and the crossing angle may include various angles, such as 21 °, 45 °, 60 °, 90 °, and the like, and when the crossing angle is 90 °, as shown in fig. 6f, the lens units 340 are arranged in a cross-shaped structure. The light-scattering member 300 is arranged by taking the lens unit 340 as a unit, the scattering lenses 310 are regularly distributed, and the light scattering of the scattering units can be adjusted by setting the number and arrangement mode of the scattering lenses 310 in the lens unit 340, so that the light-scattering member can be used to adapt to different requirements.

Alternatively, in one lens unit 340, one first diffusion lens 311 and one second diffusion lens 312 are alternately arranged. After a plurality of lens units 340 are arranged in this way, it appears that the first diffusion lens 311 is disposed between two second diffusion lenses 312. Thus, the light rays on the two sides after being scattered by the first scattering lens 311 can be respectively transmitted to the convex surface 320 surface of the corresponding second scattering lens 312 for second scattering, so that the transmission direction of the light can be further diffused towards the two sides, the light is more dispersed, the transmission path is also more prolonged, and the photodiode 200 can absorb the light more favorably, thereby improving the quantum efficiency. Moreover, the lens unit 340 is simple in structure, and the manufacturing difficulty is reduced.

Optionally, in any of the diffusers 300, edges of two adjacent diffusion lenses 310 contact or partially overlap.

The edge contact of two adjacent scattering lenses 310, referring to fig. 7a, means that the edges of two scattering lenses 310 are just opposite, such as the edges of the convex surfaces 320 of two scattering lenses 310 are tangent, so that there is a certain gap between the scattering lenses 310. Referring to fig. 7b, the edges of two adjacent scattering lenses 310 may partially overlap, that is, the edges of the convex surfaces 320 of two scattering lenses 310 have a certain overlap, so that when a plurality of scattering lenses 310 are arranged in this way, the whole scattering lenses 310 have a wave shape or a zigzag shape, and the position of each convex surface 320 cannot be identified. In the light diffuser 300 of this type, the scattering lenses 310 are distributed compactly, so that the number of scattering lenses 310 per unit area is large, and the scattering effect on light is strong, so that light is dispersed and the propagation path is also extended, which is beneficial to absorption of light by the photodiode 200, thereby improving quantum efficiency. It is understood that, referring to fig. 3, the edges of two adjacent scattering lenses 310 may not be in contact with each other, and have a certain distance therebetween. Of course, when the light diffusion member 300 is arranged by taking the lens unit 340 as a unit, the edges of two adjacent diffusion lenses 310 in the lens unit 340 can be arranged in three ways, i.e., in contact, partially overlapped or spaced.

Optionally, referring to fig. 8, the light dispersion member 300 has a first area 300a and a second area 300b surrounding the first area 300 a. At least one diffusion lens 310 in the light diffusion member 300 includes N third diffusion lenses 313 and M fourth diffusion lenses 314. The third scattering lens 313 is located in the first region 300a, and the fourth scattering lens 314 is located in the second region 300b, where N > M, and N and M are positive integers.

The second region 300b surrounds the first region 300a, it can be understood that the first region 300a is a middle region of the light dispersion member 300 and the second region 300b is an edge region of the light dispersion member 300. The number of the third diffusion lenses 313 is N, the number of the fourth diffusion lenses 314 is M, and N > M. That is, the number of the diffusion lenses 310 of the middle region of the light dispersion member 300 is greater than that of the edge region. The first area 300a corresponds to the middle area of the sensing surface 200a of the photodiode 200 covered by the light diffusion member 300, and the second area 300b corresponds to the edge area of the sensing surface 200a of the photodiode 200 covered by the light diffusion member 300. Due to the light-gathering effect of the micro-lens 31 or the shielding of the electrodes or other elements at the edges of the photodiode 200, the light-sensing surface 200a of the photodiode 200 is distributed in a manner similar to that of a case where the light is distributed more in the middle and less at the edges. Therefore, the arrangement of the scattering lenses 310 is matched with the light distribution of the light-sensing surface 200a of the photodiode 200, so that the scattering lenses 310 with the matched number are provided for different numbers of light, the requirement of improving the quantum efficiency by scattering light can be met, and the number of the scattering lenses 310 can be reduced, so that the production cost of the light-scattering member 300 is reduced. In addition, the number of the diffusion lenses 310 in the edge area of the light dispersion member 300 is small, and the difficulty in manufacturing the light dispersion member 300 is also reduced.

Optionally, the radius of the convex surface 320 is 0.5 to 1 micron. Simulation experiments prove that the scattering lens 310 with the convex surface 320 with the radius can effectively scatter light, so that the propagation direction of the light is further diverged, the light is more dispersed, the propagation path of the light is further prolonged, and the light can be absorbed by the photodiode 200 more easily, so that the quantum efficiency is improved.

Optionally, referring to fig. 9, the photodiode array 10 further includes a plurality of isolation trenches 350 and a first scattering structure 360. The isolation trenches 350 are disposed in the semiconductor substrate 100 and extend along the direction from the light-sensing surfaces 200a to the backlight surfaces 200b of the photodiodes 200. The isolation trenches 350 are disposed around a circumference of the photodiodes 200, separating adjacent two photodiodes 200. The first scattering structure 360 is disposed on a side of the isolation trench 350 facing the photodiode 200, and the first scattering structure 360 is used for scattering light incident to the isolation trench 350 to the photodiode 200.

A plurality of isolation trenches 350 are disposed in the semiconductor substrate 100 and may extend from the first surface 100a of the semiconductor substrate 100 toward the second surface 100b. The isolation trenches 350 are disposed in one-to-one correspondence with the photodiodes 200, and the isolation trenches 350 are disposed around a circumference of the corresponding photodiode 200 to be spaced apart from the adjacent photodiodes 200. The isolation trench 350 is a trench opened in the semiconductor substrate 100 and filled with a material having a relatively large refractive index, so that when light in the semiconductor substrate 100 propagates to the isolation trench 350, total reflection can occur, and light crosstalk from the light transmitted to the adjacent photodiode 200 is avoided. The material filled in the isolation trench 350 may be an oxide such as tantalum oxide, aluminum oxide, hafnium oxide, or nitrogen oxide, or an organic material having a refractive index of 1.4-3.8.

The first scattering structure 360 is disposed on a side surface of the isolation trench 350 facing the photodiode 200, and when the trench 351 is disposed, the side surface of the trench 351 may be formed in a concave-convex shape, and thus, the concave-convex structure is formed on the side surface after the material is filled. The concave-convex structure scatters light propagating to the position in the semiconductor substrate 100, and the light propagates in all directions and is easier to propagate into the photodiode 200, so that the waste of light is avoided, the propagation path is prolonged, and the quantum efficiency is improved.

Optionally, referring to fig. 9, the photodiode array 10 further includes a plurality of metal grids 370. The metal grids 370 are disposed in the semiconductor substrate 100 at the ends of the isolation trenches 350 near the light-sensing surfaces 200a of the photodiodes 200.

As mentioned above, the photodiode 200 can convert an optical signal into an electrical signal. The metal grid 370 is disposed at an end of the isolation trench 350 around a circumference of the corresponding photodiode 200, spacing it from the adjacent photodiode 200. The metal grid 370 is provided to prevent electrical crosstalk from occurring when electrical signals generated by the photodiodes 200 are transmitted to adjacent photodiodes 200. As such, the photodiode array 10 is more sensitive.

Optionally, referring to fig. 9, the photodiode array 10 further includes a second scattering structure 380, the second scattering structure 380 is disposed at a side of the semiconductor substrate 100 close to the backlight surface 200b, and the second scattering structure 380 is used for scattering light incident on the backlight surface 200b of the photodiode 200 to the photodiode 200.

The second scattering structure 380 is disposed in the semiconductor substrate 100 at a side close to the backlight surface 200b, that is, at a side close to the second surface 100b in the semiconductor substrate 100, that is, the second scattering structure 380 is disposed below the photodiode 200 and faces the photodiode 200.

Illustratively, the second scattering structure 380 may be a convex structure, the convex surface of which faces the backlight surface 200b of the semiconductor substrate 100. The second scattering structure 380 may also be a rough surface on the surface facing the backlight surface 200b of the semiconductor substrate 100. Thus, light irradiated to the rough surface can be diffused in multiple directions by diffuse reflection.

The second scattering structure 380 is configured to scatter light propagating to the bottom of the semiconductor substrate 100 to the photodiode 200 by scattering, and the light propagating to the bottom of the semiconductor substrate 100 may include one or more of the following: the light propagating from the photosensitive surface 200a to the bottom of the semiconductor substrate 100 vertically through the photodiode 200, the light scattered from the convex surface 320 and reflected to the bottom of the semiconductor substrate 100 through the isolation trench 350, or the light scattered from the convex surface 320 and scattered to the bottom of the semiconductor substrate 100 through the first scattering structure 360 of the isolation trench 350. The actual propagation process of the light is more complicated, and the intermediate process is simplified for the convenience of description. If part of the light is actually scattered by the convex surface 320, it may be refracted many times to reach the side surface of the isolation trench 350.

Example 1

A photodiode array model 1 is provided. The absorption efficiency of the photodiode array for light with wavelengths of 850nm, 400nm, 550nm and 650nm, respectively, was simulated by simulation software, and the simulation results are shown in fig. 10a and table 1. The photodiode array model comprises a semiconductor substrate, a plurality of photodiodes and a plurality of light-scattering pieces. Each light-scattering element corresponds to a photodiode, and the specific structure is shown as the structure in the dashed box shown in M1 of fig. 10 a. Each light scattering piece comprises a scattering lens, the convex radius of each scattering lens is 0.05um, and adjacent scattering lenses are arranged at intervals. The simulation results showed that the absorption efficiencies of the photodiode array for light having wavelengths of 850nm, 400nm, 550nm and 650nm were 18.60%, 65.70%, 80.20% and 68.50%, respectively. After the convex surface is added to the photodiode array, more photons can be absorbed, and the simulation result shows that the dark regions are more, which indicates that the effect of converting absorbed photons into electrons is better. The dark areas near the upper surface in fig. 10a are mainly concentrated in the middle area but have a tendency to spread towards the edge areas.

Example 2

A photodiode array model 2 is provided. The absorption efficiency of the photodiode array for light with wavelengths of 850nm, 400nm, 550nm and 650nm was simulated by simulation software, and the simulation results are shown in fig. 10b and table 1. The photodiode array model comprises a semiconductor substrate, a plurality of photodiodes and a plurality of light-scattering pieces. Each light-scattering element corresponds to a photodiode, and the specific structure is shown as the structure in the dashed box shown by M2 in fig. 10 b. Each diffuser comprises a diffuser lens, each diffuser lens has a convex surface radius of 0.1um, and adjacent diffuser lenses are in edge contact. The simulation results showed that the absorption efficiencies of the photodiode array for light having wavelengths of 850nm, 400nm, 550nm and 650nm were 13.70%, 65.40%, 77.90% and 67.60%, respectively. The dark areas near the middle of fig. 10b are evenly distributed and have been expanded to near the edge areas.

Example 3

A photodiode array model 3 is provided. The absorption efficiency of the photodiode array for light with wavelengths of 850nm, 400nm, 550nm and 650nm, respectively, was simulated by simulation software, and the simulation results are shown in fig. 10c and table 1. The photodiode array model comprises a semiconductor substrate, a plurality of photodiodes and a plurality of light-scattering pieces. Each light-scattering element corresponds to a photodiode, and the specific structure is shown as the structure in the dashed box shown by M3 in fig. 10 c. Each light scattering piece comprises two scattering lenses, wherein the convex radius of one scattering lens is 0.05um, and the convex radius of the other scattering lens is 0.1um. The two kinds of scattering lenses are alternately arranged, and the edges of the two kinds of scattering lenses are in contact. The simulation results showed that the absorption efficiencies of the photodiode array for light having wavelengths of 850nm, 400nm, 550nm and 650nm were 23.20%, 64.90%, 78% and 69.60%, respectively. The dark areas near the middle of fig. 10c are evenly distributed and have been spread to the edge areas.

Example 4

A photodiode array pattern 4 is provided. The absorption efficiency of the photodiode array for light with wavelengths of 850nm, 400nm, 550nm and 650nm was simulated by simulation software, and the simulation results are shown in fig. 10d and table 1. The photodiode array model comprises a semiconductor substrate, a plurality of photodiodes and a plurality of light-scattering pieces. Each light-scattering element corresponds to a photodiode, and the specific structure is shown as the structure in the dashed box shown by M4 in fig. 10 d. Each light scattering piece comprises a scattering lens, the convex radius of each scattering lens is 0.1um, adjacent scattering lenses are partially overlapped, and the overlapping width is 0.25um. The simulation results showed that the absorption efficiencies of the photodiode array for light having wavelengths of 850nm, 400nm, 550nm and 650nm were 26.40%, 64.60%, 78.10% and 68.40%, respectively. The dark areas of each part 10d in the figure are uniformly distributed and all extend to the edge area.

Comparative example 1

A photodiode array pattern 5 is provided. The absorption efficiency of the photodiode array for light with wavelengths of 850nm, 400nm, 550nm and 650nm was simulated by simulation software, and the simulation results are shown in fig. 10e and table 1. The photodiode array model does not include a light-scattering member, and the rest is the same as the photodiode array model 1. The simulation results are shown in fig. 10e and table 1. The simulation results showed that the absorption efficiencies of the photodiode array for light having wavelengths of 850nm, 400nm, 550nm and 650nm were 13.30%, 64.90%, 77.60% and 67.10%, respectively. The dark areas of the parts 10e in the figure are mainly concentrated in the middle area.

Table 1 absorption efficiency simulation results of photodiode array model

	850nm	400nm	550nm	650nm
					Comparative example 1	13.30％	64.90％	77.60％	67.10％
Example 1	13.70％	65.40％	77.90％	67.60％
					Example 2	18.60％	65.70％	80.20％	68.50％
Example 3	23.20％	64.90％	78％	69.60％
					Example 4	26.40％	64.60％	78.10％	68.40％

From the above simulation results, although the absorption efficiency of example 1 for light having a wavelength of 850nm is not significant, the dark region distribution pattern near the upper surface in fig. 10a shows that it absorbs light having a wavelength of 850nm better than comparative example 1. And comparing fig. 10a to 10e together, the photon absorption is concentrated mainly in the lower half of the silicon substrate in fig. 10a to 10d, compared to the pattern 10e without the added near infrared enhancement, and the absorption is significantly higher than 10e in the surface and middle region of the silicon substrate. Fig. 10a to 10d can all show the case where the dark regions have a larger area than fig. 10e, illustrating that the surface absorption is enhanced after the light dispersion member is added to fig. 10a to 10 d.

The absorption efficiency of examples 2 to 4 for light having a wavelength of 850nm is significantly improved as compared with comparative example 1, and the distribution of dark regions in the figure supports this conclusion. Overall, it is consistent that examples 1 to 4 have improved absorption efficiency for light having a wavelength of 850nm as compared with comparative example 1, and absorption efficiency for light having wavelengths of 400nm, 550nm and 650nm is substantially the same as that of comparative example 1, because the photodiode has relatively high absorption efficiency for light having a shorter wavelength, and can have a higher absorption rate without providing a light diffusion member.

The photodiode array model 1 to the photodiode array model 4 can significantly increase the absorption efficiency of near infrared light. Therefore, the photodiode array of the embodiment of the application can improve the quantum efficiency of the photodiode array to near infrared light.

Referring to fig. 11, the present embodiment further provides a method for manufacturing a photodiode array, where the method includes:

s1, forming a plurality of photodiodes distributed in an array in a semiconductor substrate; wherein, the first and the second end of the pipe are connected with each other, the photodiode has a light-sensing surface and a backlight surface.

And S2, forming a plurality of light scattering pieces on one side, close to the photosensitive surface, in the semiconductor substrate, wherein the plurality of light scattering pieces correspond to the plurality of photodiodes one by one, and the light scattering pieces are used for scattering light penetrating through the light scattering pieces.

Before forming a plurality of light-scattering members in the semiconductor substrate on the side close to the light-sensing surface in S2, the method includes: and forming a plurality of arc-shaped grooves on the surface of one side of the semiconductor substrate close to the light sensing surface.

Forming a plurality of light scattering members in the semiconductor substrate on a side adjacent to the photosensitive surface includes: a scattering lens is formed in one arc-shaped groove, the surface of the scattering lens, facing the arc-shaped groove, is an arc surface, and the arc surface is the same as the arc surface of the arc-shaped groove in radian. At least one of the diffusion lenses constitutes a diffuser.

Wherein, it includes to form a plurality of arc recesses at semiconductor substrate near the surface of one side of photosurface: and forming a plurality of arc-shaped grooves on the surface of one side of the semiconductor substrate close to the photosensitive surface by adopting an isotropic etching process. The light scattering member is easily formed on the surface of one side of the semiconductor substrate close to the light-sensing surface by the isotropic etching process, so that the incident light irradiated to the light diffusion member is diffused through the light diffusion member.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A photodiode array, comprising:

a semiconductor substrate;

the photodiodes are arranged in the semiconductor substrate and distributed in an array mode, and each photodiode is provided with a light sensing surface and a backlight surface;

and the light scattering pieces are arranged on one side, close to the photosensitive surface, in the semiconductor substrate, correspond to the photodiodes one by one and are used for scattering light penetrating through the light scattering pieces.

2. The photodiode array of claim 1, wherein each of the light diffusers comprises at least one scattering lens having a convex surface facing a photosensitive surface of the corresponding photodiode of the scattering lens, the scattering lens being configured to scatter light transmitted through the scattering lens.

3. The photodiode array of claim 2, wherein a vertical projection of the scattering lens on the semiconductor substrate overlaps a vertical projection of the photodiode on the semiconductor substrate.

4. The photodiode array of claim 2, wherein in any of the diffusers, the diffuser lenses comprise at least one first diffuser lens and at least one second diffuser lens, and a radius of a convex surface of the first diffuser lens is smaller than a radius of a convex surface of the second diffuser lens.

5. The photodiode array of claim 4, wherein at least one of the first scattering lenses and at least one of the second scattering lenses are arranged in a row to form a lens unit;

the lens units are distributed in an array mode, or the lens units are distributed in a crossed mode.

6. The photodiode array of claim 5, wherein in one of the lens units, one of the first diffusion lenses and one of the second diffusion lenses are arranged alternately.

7. The photodiode array of claim 2, wherein in any one of the diffusers, edges of two adjacent scattering lenses are in contact or partially overlap.

8. The photodiode array of claim 2, wherein the diffuser has a first region and a second region surrounding the first region;

at least one of the diffusion lenses in the diffuser includes N third diffusion lenses and M fourth diffusion lenses; the third scattering lens is positioned in the first area, and the fourth scattering lens is positioned in the second area; wherein N > M, and both N and M are positive integers.

9. The photodiode array of claim 2, wherein the radius of the convex surface comprises 0.5 to 1 micron.

10. The photodiode array of any of claims 1-9, further comprising:

a plurality of isolation trenches disposed in the semiconductor substrate and extending in a direction from the light sensing surfaces to the backlight surfaces of the plurality of photodiodes; the isolation channel is arranged around one circle of the photodiode and separates two adjacent photodiodes;

the first scattering structure is arranged on the side face, facing the photodiode, of the isolation channel and is used for scattering light incident to the isolation channel to the photodiode.

11. The photodiode array of claim 10, further comprising:

and the metal grids are arranged in the semiconductor substrate and are positioned at the end parts of the isolation channels, which are close to the light-sensitive surfaces of the photodiodes.

12. The photodiode array of any one of claims 1-9, further comprising:

and the second scattering structure is arranged on one side, close to the backlight surface, in the semiconductor substrate and is used for scattering light incident to the backlight surface of the photodiode to the photodiode.

13. A method of fabricating a photodiode array, the method comprising:

forming a plurality of photodiodes distributed in an array in a semiconductor substrate; wherein the photodiode has a light sensing surface and a backlight surface;

and forming a plurality of light-scattering pieces on one side, close to the photosensitive surface, in the semiconductor substrate, wherein the plurality of light-scattering pieces correspond to the plurality of photodiodes one to one, and the light-scattering pieces are used for scattering light penetrating through the light-scattering pieces.

14. The method of manufacturing a photodiode array according to claim 13,

before the forming of the plurality of light scattering members in the semiconductor substrate on the side close to the photosensitive surface, the method comprises the following steps: forming a plurality of arc-shaped grooves on the surface of one side, close to the photosensitive surface, of the semiconductor substrate;

the forming of the plurality of light scattering members in the semiconductor substrate on the side close to the photosensitive surface comprises: a scattering lens is formed in one arc-shaped groove, the surface, facing the arc-shaped groove, of the scattering lens is an arc surface, the radian of the arc surface is the same as that of the arc surface of the arc-shaped groove, and at least one scattering lens forms one light-scattering part.

15. The method of manufacturing a photodiode array according to claim 13 or 14,

the forming of the plurality of arc-shaped grooves on the surface of the semiconductor substrate close to one side of the photosensitive surface comprises: and forming a plurality of arc-shaped grooves on the surface of one side, close to the photosensitive surface, of the semiconductor substrate by adopting an isotropic etching process.

16. A sensor, comprising: a lens layer, a dielectric layer, and the photodiode array of any one of claims 1-12; the photodiode array, the dielectric layer and the lens layer are sequentially stacked.

17. The sensor of claim 16, wherein the dielectric layer is integrally connected to the scattering lens of the photodiode array and is made of the same material.

18. A camera, comprising:

a lens assembly;

a sensor as claimed in claim 16 or 17, provided at the light exit side of the lens assembly.

19. An electronic device, comprising:

a shell body, a plurality of first connecting rods and a plurality of second connecting rods,

the camera of claim 16 or 17, at least a portion of the camera being embedded within the housing.

20. The electronic device of claim 19, further comprising an emitting end, wherein the emitting end is configured to emit a detection light toward an object to be measured, and the camera is configured to receive a reflected light of the detection light reflected by the object to be measured.