CN217062113U - Photodiode and photodiode detector - Google Patents

Abstract

The utility model provides a photodiode and photodiode detector. The photodiode includes a first conductivity type substrate having opposing first and second surfaces; the photodiode further comprises a first conductive injection layer, a second conductive injection layer, an electrode wire, a first connecting hole and a third injection region, wherein the first conductive injection layer and the second conductive injection layer are positioned in the first conductive type substrate and are respectively exposed from the first surface and the second surface of the first conductive type substrate, the first conductive injection layer and the second conductive injection layer are both made of second conductive type materials, the electrode wire is arranged on the outer side of the second surface of the first conductive type substrate, and the electrode wire comprises a first electrode wire electrically connected with the second injection region; a first electric connecting column for connecting the first injection region and the first electrode wire is arranged in the first connecting hole; the third injection region is positioned in the first conductive type substrate and at the periphery of the second injection region, and the material of the third injection region is the first conductive type material. The structure is beneficial to improving the collection efficiency of photon-generated carriers.

Description

Photodiode and photodiode detector

Technical Field

The utility model belongs to the technical field of the semiconductor, especially, relate to a photodiode and photodiode detector.

Background

Compared with the traditional front-illuminated photodiode detector, the back-illuminated photodiode has the advantages of high mounting reliability, small pixel pitch, easiness in splicing, small crosstalk, good consistency and the like in the application of an array module; since the space charge region of the back-illuminated photodiode is located at the inner side close to the front surface, the substrate needs to be thinned to ensure light entering from the back surface. In this way, the absorption path of the incident light in the substrate is easily reduced, and particularly, the absorption efficiency of the long wave is reduced, so that the photo-generated carriers generated in the space charge region are reduced, thereby causing a reduction in the optical responsivity of the semiconductor device having the back-illuminated photodiode.

SUMMERY OF THE UTILITY MODEL

According to the first aspect of the embodiment of the utility model, provide a photodiode, photodiode includes:

a first conductivity type substrate having opposing first and second surfaces;

a first implanted region in the first conductivity-type substrate and exposed from a first surface of the first conductivity-type substrate; the material of the first injection region is a second conductive type material;

a second implanted region in the first conductivity-type substrate and exposed from a second surface of the first conductivity-type substrate; the material of the second injection region is a second conductive type material;

the electrode wire is arranged on the outer side of the second surface of the first conductive type substrate and comprises a first electrode wire electrically connected with the second injection region;

a first via hole having a first electrical connection post therein connecting the first injection region and the first electrode line;

and the third injection region is positioned in the first conductive type substrate and positioned at the periphery of the second injection region, and the material of the third injection region is the first conductive type material.

In some embodiments, the electrode lines further comprise second electrode lines electrically connected to the third implant regions.

In some embodiments, the photodiode is provided with a plurality of first via holes.

In some embodiments, the plurality of first via holes are arranged in an array in the first conductive type substrate.

In some embodiments, the photodiode includes two first connection holes oppositely arranged in a length direction of the photodiode, the first connection holes extend in a width direction of the photodiode, a long-shaped communication hole is formed, and a wall-shaped first connection column extending in the width direction of the photodiode is formed in the first connection holes.

In some embodiments, an insulating layer is formed on the hole wall of the first via hole, and the first electrical connection pillar is disposed in the insulating layer.

In some embodiments, the photodiode further comprises a first electrode and a second electrode; the first electrode is arranged on one side of the second surface of the first conductive type liner and connected to the outer side of the first electrode wire, and the second electrode is arranged on one side of the second surface of the first conductive type liner and connected to the outer side of the second electrode wire.

In some embodiments, the first conductivity type substrate has a thickness in a range of 300 μm to 700 μm.

In some embodiments, the photodiode includes a fourth implantation region located in the first conductive type substrate and at the periphery of the first implantation region, and the material of the fourth implantation region is the first conductive type material;

a second communication hole is formed in the photodiode, and a second electric connection column used for connecting the third injection region and the fourth injection region is formed in the second communication hole;

the photodiode comprises a third conductive trace layer and a fourth conductive trace layer which are arranged outside the first surface of the first conductive type substrate, the third conductive trace layer is electrically connected with the first injection area, and the second electrode wire is electrically connected with the third injection area.

According to a second aspect of the embodiments of the present invention, there is provided a photodiode detector, the photodiode detector includes a plurality of photodiodes as described above, the plurality of photodiodes are arranged in an array.

Based on the technical scheme, the two layers of space charge areas are formed on the inner sides of the two opposite surfaces of the first conduction type substrate, so that the light absorption rate is favorably improved, the collection efficiency of photon-generated carriers is improved, and the photocurrent response of a device with the photodiode is improved.

Drawings

Fig. 1 is a cross-sectional view of a photodiode according to an embodiment of the present invention;

FIG. 2 is a bottom view of the photodiode of FIG. 1 with the passivation layer removed;

FIG. 3 is a schematic bottom view of the photodiode shown in FIG. 1 with the dielectric layer, the passivation layer, the first electrode lines and the second electrode lines removed;

fig. 4 is a schematic bottom view of a photodiode according to another embodiment of the present invention, showing a dielectric layer, a passivation layer, first electrode lines and second electrode lines removed;

fig. 5 is a cross-sectional view of a photodiode according to another embodiment of the present invention;

fig. 6 is a schematic bottom view of the photodiode shown in fig. 5 with the dielectric layer, the passivation layer, the first electrode lines and the second electrode lines removed.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Embodiments of the present invention are described in detail below with reference to the accompanying drawings.

An embodiment of the present invention provides a photodiode, including:

a first conductivity type substrate having opposing first and second surfaces;

a first implanted region in the first conductivity type substrate and exposed from a first surface of the first conductivity type substrate; the material of the first injection region is a second conductive type material;

a second implanted region in the first conductivity type substrate and exposed from the second surface of the first conductivity type substrate; the material of the second injection region is a second conductive type material;

the electrode wire is arranged on the outer side of the second surface of the first conductive type substrate and comprises a first electrode wire electrically connected with the second injection region;

a first via hole having a first electrical connection post therein connecting the first injection region and the first electrode line;

and the third injection region is positioned in the first conduction type substrate and is positioned at the periphery of the second injection region.

According to the photodiode, the two layers of space charge areas are formed on the inner sides of the two opposite surfaces of the first conduction type substrate, so that the light absorption rate is favorably improved, the collection efficiency of photon-generated carriers is improved, and the photocurrent response of a device with the photodiode is improved.

The photodiode provided in the present application is described in detail below with reference to fig. 1 to 6.

Fig. 1 is a cross-sectional view of a photodiode 100 according to an embodiment of the present invention, and referring to fig. 1 and fig. 2 and fig. 3 as necessary, the photodiode 100 includes a first conductive type substrate 10, and a first implantation region 20, a second implantation region 30, an electrode line, a first via hole 40, and a third implantation region 51 are formed in the first conductive type substrate 10. Therein, a first conductivity type substrate 10 has opposing first and second surfaces 1001, 1002. The first implantation region 20 is located in the first conductive type substrate 10 and exposed from the first surface 1001 of the first conductive type substrate 10; wherein the material of the first implantation region 20 is a second conductive type material. The second implantation region 30 is located in the first conductive type substrate 10 and exposed from the second surface 1002 of the first conductive type substrate 10; wherein the material of the second implantation region 30 is a second conductive type material. The electrode lines are disposed outside the second surface 1002 of the first conductive type substrate 10, and the electrode lines include the first electrode lines 61 electrically connected to the second implantation regions 30. A first electrical connection post 402 connecting the first implanted region 20 and the first electrode line 61 is provided in the first connection hole 40. The third implant region 51 is located in the first conductive type substrate 10 and at the periphery of the second implant region 30.

Here, the side where the first surface 1001 of the first conductivity type substrate 10 is located is a light incident side, and the photodiode 100 is a back-illuminated photodiode. The material of the first and second implant regions 20 and 30 has a photosensitive material, and the first and second implant regions 20 and 30 form two photosensitive regions, respectively, thereby forming space charge regions near the first and second implant regions 20 and 30, respectively.

In some embodiments, the first conductivity type is N-type and the second conductivity type is P-type. The first conductive type material is an N-type material, and the second conductive type material is a P-type material. The first implant region 20 and the second implant region 30 are P-type implant regions. The third implant region 51 is an N-type implant region. Accordingly, the first and second implant regions 20 and 30 may be formed by implanting a P-type dopant material. The third implantation region 51 may be formed by implanting an N-type dopant material. The doping concentration of the N-type doping material of the third implantation region 51 is higher than that of the N-type doping material in the N-type substrate.

Here, the third implantation region 51 is located at the periphery of the second implantation region 30, and may form a closed ring-shaped region as shown in fig. 3, or may be an unclosed ring-shaped region. A size of the third implantation region 51 in the thickness direction of the first conductive type substrate 10 may be larger than a size of the second implantation region 30 in the thickness direction of the first conductive type substrate 10.

The first electrode lines 61 may be connected to the second implantation regions 30 near the edge.

Here, the first communication hole 40 may be formed by mechanical drilling or laser drilling.

The photodiode 100 may further include a dielectric layer 110 disposed on the second surface 1002 of the first conductive type substrate 10. Specifically, a portion of the electrode line passes through dielectric layer 110, and another portion of the electrode line is disposed on a side of dielectric layer 110 away from first conductivity-type substrate 10. Further, the electrode lines further include a second electrode line 71. The second electrode lines 71 are electrically connected to the third implantation regions 51. The third implant region 51 may be exposed from the second surface 1002 of the first conductive type substrate 10. The dielectric layer is formed of an insulating material.

Correspondingly, the photodiode further comprises a first electrode 81 and a second electrode 82. The first electrode 81 is disposed on one side of the second surface 1002 of the first conductive type substrate 10 and connected to the outer side of the first electrode line 61, and the second electrode 82 is disposed on one side of the second surface 1002 of the first conductive type substrate 10 and connected to the outer side of the second electrode line 71, so as to facilitate connection of an external power source.

The first electrode line 61 here is an anode conductive layer, and the first electrode 81 is an anode. Here, the second electrode line 71 is a cathode conductive layer, and the second electrode 82 is a cathode. The first electrical connection post 402 may be connected to the first electrode line 61 and the first implantation region 20.

In some embodiments, the photodiode 100 is provided with a plurality of first through vias 40.

In some embodiments, the plurality of first through holes 40 are arrayed in the first conductive type substrate 10. The array arrangement here may be a symmetrical arrangement or a uniform arrangement, so as to collect photo-generated carriers more uniformly, and further improve the photocurrent response of the device with the photodiode (as shown in fig. 3).

The wall of the first via is formed with an insulating layer 401, and a first electrical connection post 402 is disposed within the insulating layer 401.

The insulating layer 401 here may be formed by depositing an insulating material on the inner wall of the first via hole 40, or may be formed by oxidizing the hole wall of the first via hole 40.

In other embodiments, as shown in fig. 4, the first via hole 40 may extend along the width direction W of the photodiode 100 to form a strip-shaped via hole, and accordingly, a wall-shaped first electrical connection column extending along the width direction W of the photodiode 100 is formed in the first via hole 40. The photodiode 100 includes two opposing elongated first via holes to form two opposing wall-shaped first electrical connection posts to prevent cross-talk between the photodiode 100 and other photodiodes adjacent thereto in the length direction L thereof.

Further, in some embodiments, the first conductive type substrate 10 has a thickness in a range of 200 μm to 700 μm.

Further, in some embodiments, the first surface 1001 of the first conductive type substrate 10 is provided with an anti-reflection layer 91 at a side thereof. The anti-reflection layer 91 covers at least the surface of the first implantation region 20. Of course, the remaining first surface 1001 of the first conductive type substrate 10 may be covered.

Further, the side of the first conductive type substrate 10 where the second surface 1002 is located is provided with a passivation layer 93. The passivation layer 93 covers at least the surfaces of the first electrode lines 61, the second electrode lines 71, and the second implantation regions 30. Of course, the remaining second surface 1002 of the first conductive type substrate 10 may be covered.

As shown in fig. 5 and 6, fig. 5 is a cross-sectional view of a photodiode 200 according to another embodiment of the present invention; fig. 6 is a schematic bottom view of the photodiode shown in fig. 5 with the dielectric layer, the passivation layer, the first electrode lines and the second electrode lines removed.

Unlike the photodiode 100 described above, the photodiode 200 includes, in addition to the structure of the photodiode 100 except for the passivation layer 93, a fourth implantation region 52, where the fourth implantation region 52 is located in the first conductivity type substrate 10 and at the periphery of the first implantation region 20, and the fourth implantation region 52 is made of the first conductivity type material.

A second via hole 101 is provided in the photodiode 200, and a second electrical connection post 102 connecting the third implantation region 51 and the fourth implantation region 52 is provided in the second via hole 101.

The photodiode 200 includes a third conductive trace layer 62 and a fourth conductive trace layer 72 disposed outside the first surface 1001 of the first conductivity type substrate 10, the third conductive trace layer 62 being electrically connected to the first implanted region 20, the fourth conductive trace layer 72 being electrically connected to the fourth implanted region 52.

The first surface and the second surface can be selectively used as the incident light side according to actual conditions.

Compared to the photodiode 100, the photodiode 200 can be selected according to the light incident surface, so that the package thereof has a certain flexibility.

It should be noted that, in some other embodiments, the first conductive type material may also be a P-type material, and the second conductive type material is correspondingly an N-type material. The first electrode is correspondingly a cathode and the second electrode is an anode.

The present application further provides a photodiode detector. The photodiode detector comprises a plurality of photodiodes 100 or 200, and the photodiodes 100 or 200 are arranged in an array.

Those skilled in the art will appreciate that the drawings are merely schematic representations of preferred embodiments and that the blocks or flowchart illustrations in the drawings are not necessarily required to practice the present invention. The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. A photodiode, comprising:

a first conductivity type substrate having opposing first and second surfaces;

a first implanted region in the first conductivity-type substrate and exposed from a first surface of the first conductivity-type substrate; the material of the first injection region is a second conductive type material;

a second implanted region in the first conductivity-type substrate and exposed from a second surface of the first conductivity-type substrate; the material of the second injection region is a second conductive type material;

the electrode wire is arranged on the outer side of the second surface of the first conductive type substrate and comprises a first electrode wire electrically connected with the second injection region;

a first via hole having a first electrical connection post therein connecting the first injection region and the first electrode line;

and the third injection region is positioned in the first conductive type substrate and positioned at the periphery of the second injection region, and the material of the third injection region is the first conductive type material.

2. The photodiode of claim 1, wherein the electrode lines further comprise second electrode lines electrically connected to the third implant region.

3. The photodiode of claim 1, wherein the photodiode is provided with a plurality of first via holes.

4. The photodiode of claim 3, wherein the plurality of first via holes are arrayed in the first conductivity type substrate.

5. The photodiode of claim 3, wherein the photodiode includes two first via holes oppositely arranged in a length direction of the photodiode, the first via holes extending in a width direction of the photodiode to form a strip-shaped via hole, the first via holes forming wall-shaped first connection pillars extending in the width direction of the photodiode.

6. The photodiode of claim 1, wherein a wall of the first via hole is formed with an insulating layer, and the first electrical connection post is disposed within the insulating layer.

7. The photodiode of claim 2, further comprising a first electrode and a second electrode; the first electrode is arranged on one side of the second surface of the first conductive type liner and connected to the outer side of the first electrode wire, and the second electrode is arranged on one side of the second surface of the first conductive type liner and connected to the outer side of the second electrode wire.

8. The photodiode of claim 1, wherein the first conductivity type substrate has a thickness in a range of 300 μ ι η to 700 μ ι η.

9. The photodiode of claim 2 or 7, wherein the photodiode comprises a fourth implanted region in the first conductivity type substrate and located at a periphery of the first implanted region, the fourth implanted region being of the first conductivity type material;

a second through hole is formed in the photodiode, and a second electric connection column for connecting the third injection region and the fourth injection region is formed in the second through hole;

the photodiode comprises a third conductive trace layer and a fourth conductive trace layer which are arranged outside the first surface of the first conductive type substrate, the third conductive trace layer is electrically connected with the first injection area, and the second electrode wire is electrically connected with the third injection area.

10. A photodiode detector, comprising a plurality of photodiodes according to any one of claims 1 to 9 arranged in an array.

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