CN117894813B - Preparation method of photodetector - Google Patents

Abstract

The application provides a preparation method of a photoelectric detector. The preparation method of the photoelectric detector comprises the following steps: providing a substrate with a functional layer, wherein the functional layer comprises a plurality of photoelectric detection elements arranged in an array; forming a solder film layer on the surface of the functional layer, which is far away from the substrate, wherein the solder film layer covers the surface of the functional layer, which is far away from the substrate; placing the imprinting template on one side of the solder film layer away from the substrate; a plurality of grooves which are distributed at intervals are arranged on one side of the imprinting template facing the solder film layer; pressurizing the imprinting template to enable the imprinting template to partially enter the solder film layer so as to extrude partial materials of the solder film layer into the grooves to form a protruding structure; separating the stamping template from the solder film layer, etching the solder film layer, and etching at least the part of the solder film layer between adjacent convex structures to obtain a plurality of solder columns which are arranged at intervals, wherein the solder columns are electrically connected with the photoelectric detection element.

Description

Preparation method of photodetector

Technical Field

The present application relates to the field of photoelectric detection technology, and in particular to a method for preparing a photoelectric detector.

Background technique

Photodetectors are used to convert optical signals into electrical signals. With the advancement of science and technology and the development of society, their application fields are becoming wider and wider, and they are widely used in the fields of medical treatment, optical communication, industrial detection, etc. Photodetectors include multiple array-arranged photodiodes and multiple welding protrusions located on one side of the photodiodes. Each photodiode is electrically connected to a welding protrusion, and the welding protrusions are used to weld with the signal processor to achieve physical and electrical connection between the signal processor and the photodiode.

Currently, a photolithography stripping process is usually used to prepare welding bosses. The photolithography stripping process includes coating photoresist, exposing the photoresist using a mask, developing the exposed photoresist to form a through hole, forming solder in the through hole using an electroplating process, stripping and removing the photoresist, and other process steps. The preparation process of the boss is relatively complicated.

Summary of the invention

The present application provides a method for preparing a photoelectric detector. The method for preparing a photoelectric detector comprises:

Providing a substrate having a functional layer formed thereon, wherein the functional layer includes a plurality of photoelectric detection elements arranged in an array;

forming a solder film layer on a surface of the functional layer away from the substrate, wherein the solder film layer covers the surface of the functional layer away from the substrate;

Placing the embossing template on the side of the solder film layer away from the substrate; a plurality of grooves arranged at intervals are provided on the side of the embossing template facing the solder film layer;

Pressurizing the stamping template so that the stamping template partially enters the solder film layer, so as to squeeze part of the material of the solder film layer into the groove to form a protruding structure;

The imprint template is separated from the solder film layer, and the solder film layer is etched, at least the portion of the solder film layer between adjacent protruding structures is etched away to obtain a plurality of solder columns arranged at intervals, and the solder columns are electrically connected to the photoelectric detection element.

In one embodiment of the present application, the preparation method further includes: while pressurizing the imprint template, heating the solder film layer, and the heating temperature is respectively lower than the melting point of the material of the solder film layer and the melting point of the material of the imprint template.

In one embodiment of the present application, etching the solder film layer includes:

The surface of the solder film layer away from the substrate is etched, and the etching speed of each part of the surface of the solder film layer away from the substrate is substantially the same.

In one embodiment of the present application, etching the surface of the solder film layer away from the substrate includes: etching the surface of the solder film layer away from the substrate using an ion beam etching process.

In one embodiment of the present application, the material of the imprint template is a non-metallic material.

In one embodiment of the present application, the material of the imprint template includes at least one of silicon oxide and silicon nitride.

In one embodiment of the present application, the cross-sectional area of the groove gradually increases in a direction from the imprint template to the substrate.

In one embodiment of the present application, the bottom surface of the groove is a plane.

In one embodiment of the present application, the distance between the geometric centers of the bottom surfaces of adjacent grooves is less than or equal to 5 μm; and/or,

The depth of the groove is greater than or equal to 3 μm; and/or,

The ratio of the maximum width of the bottom surface of the groove to the distance between the geometric centers of the bottom surfaces of adjacent grooves is less than or equal to 90%.

In one embodiment of the present application, a distance between geometric centers of orthographic projections of adjacent solder pillars on the substrate is less than or equal to 5 μm.

In one embodiment of the present application, the depth of the groove is less than the thickness of the solder film layer.

In one embodiment of the present application, etching the surface of the solder film layer includes: etching the surface of the solder film layer using an ion beam etching process.

In one embodiment of the present application, the material of the solder film layer is indium.

The preparation method of the photodetector provided in the embodiment of the present application first pressurizes the imprint template located on the side of the solder film layer away from the substrate to squeeze part of the material of the solder film layer into the groove of the imprint template, and then etches the solder film layer to obtain a plurality of solder columns arranged at intervals; it can be seen that the preparation process of the solder column in the preparation method of the photodetector provided in the embodiment of the present application is simple, which can shorten the time for preparing the photodetector; after etching the solder film layer, at least etching away the part of the solder film layer located between adjacent protruding structures, the distance between adjacent solder columns in the obtained multiple solder columns is the same as the distance between adjacent protruding structures, that is, the same as the distance between adjacent grooves, and the distance between the centers of adjacent solder columns can be adjusted by adjusting the distance between adjacent grooves of the imprint template. Therefore, the solder column can be prepared by using an imprint template with a smaller distance between adjacent grooves to achieve the purpose of reducing the distance between adjacent solder columns, thereby meeting the requirements of small-sized photoelectric detection elements in photodetectors for solder columns.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a method for preparing a photodetector provided by an exemplary embodiment of the present application;

FIG2 is a partial cross-sectional view of a first intermediate structure provided by an exemplary embodiment of the present application;

FIG3 is a partial cross-sectional view of a second intermediate structure provided by an exemplary embodiment of the present application;

FIG4 is a partial cross-sectional view of a third intermediate structure provided by an exemplary embodiment of the present application;

FIG5 is a partial cross-sectional view of a fourth intermediate structure provided by an exemplary embodiment of the present application;

FIG. 6 is a partial cross-sectional view of a photodetector provided by an exemplary embodiment of the present application.

Detailed ways

Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and/or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

The following will describe in detail the method for preparing the photoelectric detector provided in the embodiment of the present application in conjunction with the accompanying drawings. In the absence of conflict, the features in the following embodiments can complement or be combined with each other.

The embodiment of the present application provides a method for preparing a photoelectric detector. Referring to FIG1 , the method for preparing a photoelectric detector includes the following steps 110 to 150 .

In step 110 , a substrate having a functional layer formed thereon is provided, wherein the functional layer includes a plurality of photoelectric detection elements arranged in an array.

In step 120, a solder film layer is formed on a surface of the functional layer away from the substrate, and the solder film layer covers the surface of the functional layer away from the substrate.

In step 130, an imprinting template is placed on a side of the solder film layer away from the substrate; a side of the imprinting template facing the solder film layer is provided with a plurality of grooves arranged at intervals.

In step 140, the imprinting template is pressurized so that the imprinting template partially enters the solder film layer, so as to squeeze part of the material of the solder film layer into the groove to form a protruding structure.

In step 150, the imprint template is separated from the solder film layer, and the solder film layer is etched, at least the portion of the solder film layer between adjacent protruding structures is etched away to obtain a plurality of solder columns arranged at intervals, and the solder columns are electrically connected to the photoelectric detection element.

The preparation method of the photodetector provided in the embodiment of the present application first pressurizes the imprint template located on the side of the solder film layer away from the substrate to squeeze part of the material of the solder film layer into the groove of the imprint template, and then etches the solder film layer to obtain a plurality of solder columns arranged at intervals; it can be seen that the preparation process of the solder column in the preparation method of the photodetector provided in the embodiment of the present application is simple, which can shorten the time for preparing the photodetector; after etching the solder film layer, at least etching away the part of the solder film layer located between adjacent protruding structures, the distance between adjacent solder columns in the obtained multiple solder columns is the same as the distance between adjacent protruding structures, that is, the same as the distance between adjacent grooves, and the distance between the centers of adjacent solder columns can be adjusted by adjusting the distance between adjacent grooves of the imprint template. Therefore, the solder column can be prepared by using an imprint template with a smaller distance between adjacent grooves to achieve the purpose of reducing the distance between adjacent solder columns, thereby meeting the requirements of small-sized photoelectric detection elements in photodetectors for solder columns. When the distance between adjacent solder columns is small, in the process of preparing the solder columns by the photolithography stripping process, the solder columns formed by the electroplating process may cover the surface of the photoresist, and the subsequent process of stripping the photoresist will cause the solder columns to fall off, or drive the top part of the solder column to separate from other parts, thereby resulting in poor height uniformity of the solder columns, affecting the electrical connection effect between the solder columns and the signal processor. The preparation method of the photoelectric detector provided in the embodiment of the present application does not require the use of a photolithography stripping process, can effectively improve the problem of solder column falling off, and can improve the height uniformity of the solder columns, thereby improving the electrical connection effect between the solder columns and the signal processor.

The following is an introduction to the steps of the method for preparing the photoelectric detector provided in the embodiment of the present application.

In step 110 , a substrate having a functional layer formed thereon is provided, wherein the functional layer includes a plurality of photoelectric detection elements arranged in an array.

In one embodiment, the photodetection element is a photodiode.

In one embodiment, the functional layer further comprises an insulating layer, the insulating layer is located on a side of the photoelectric detection element away from the substrate, the insulating layer is provided with a through hole, the through hole of the insulating layer exposes the electrode of the photoelectric detection element, and the solder column can be electrically connected to the electrode of the photoelectric detection element through the through hole of the insulating layer. The area of the insulating layer where the through hole is not provided is substantially flush with the surface of the substrate away from the substrate, so that the surface of the solder film layer formed in step 120 can be substantially flush.

In step 120, a solder film layer is formed on a surface of the functional layer away from the substrate, and the solder film layer covers the surface of the functional layer away from the substrate.

Through this step, a first intermediate structure as shown in FIG2 can be obtained. As shown in FIG2, the solder film layer 30 is located on the side of the functional layer 20 away from the substrate 10. The surface of the solder film layer 30 away from the substrate 10 is substantially flush, which helps to improve the height uniformity of the solder column formed subsequently, and further helps to improve the electrical connection effect between the solder column and the signal processor after the solder column and the signal processor are soldered.

In one embodiment, an evaporation coating process can be used to form a solder film layer on the surface of the functional layer away from the substrate. During the evaporation coating process, the material of the solder film layer 30 partially enters the through hole of the insulating layer and is electrically connected to the electrode of the photoelectric detection element. The morphology of the solder film layer formed by the evaporation coating process is good, which can make the surface flatness of the solder film layer away from the substrate better.

In one embodiment, the material of the solder film layer is indium. Indium has good ductility. When the solder film layer is stamped with an imprinting template, the solder film layer is more likely to deform to form a convex structure, which can reduce the difficulty of the stamping process; and indium is not easily oxidized at room temperature, which can ensure the welding effect of the solder column and the signal processor.

In one embodiment, the thickness of the solder film layer ranges from 5 μm to 15 μm. The thickness of the solder film layer can be determined according to the height of the solder column to be formed, and the thickness of the solder film layer is greater than the height of the solder column to be formed.

In step 130, an imprinting template is placed on a side of the solder film layer away from the substrate; a side of the imprinting template facing the solder film layer is provided with a plurality of grooves arranged at intervals.

Through this step, a second intermediate structure as shown in FIG3 can be obtained. As shown in FIG3, the size and shape of the multiple grooves 41 of the imprint template 40 are the same, so that the size and shape of the multiple protrusion structures formed in the subsequent steps can be basically the same. The size of the groove 41 includes the depth of the groove 41 and the area of each cross section of the groove 41 parallel to the substrate 10; the size of the protrusion structure includes the height of the protrusion structure and the area of each cross section of the protrusion structure parallel to the substrate 10.

In one embodiment, the material of the embossing template 40 is a non-metallic material. In the subsequent process of embossing the solder film layer using the embossing template, the solder film layer can be heated. By setting the material of the embossing template to be a non-metallic material, it can be avoided that during the process of embossing the solder film layer by the embossing template, the material of the solder film layer and the material of the embossing template are fused due to the increase in temperature, which makes it difficult to separate the embossing template from the solder film layer after the embossing is completed. It can also be avoided that the material of the solder film layer reacts with the material of the embossing template to form an alloy, which affects the welding effect of the solder column and the signal processor.

In one embodiment, the material of the imprint template 40 includes at least one of silicon oxide and silicon nitride. In this way, the melting point of the material of the imprint template 40 is above 2000 degrees, which can effectively prevent the imprint template from melting and deforming during the imprinting process, thereby affecting the continued use of the imprint template and improving the service life of the imprint template; and the material of the imprint template 40 is easy to obtain, and the cost of the imprint template is low.

In one embodiment, as shown in FIG3 , the cross-sectional area of the groove 41 gradually increases in the direction from the imprint template 40 to the substrate 10. The cross-sectional area of the groove 41 refers to the cross-sectional area parallel to the surface of the substrate 10. In this way, in the direction from the imprint template 40 to the substrate 10, the width of the portion of the imprint template 40 located between adjacent grooves 41 gradually decreases, and in the process of pressurizing the imprint template 40 to make it enter the solder film layer 30, the imprint template 40 is subjected to less resistance, and it is easier for the imprint template 40 to enter the solder film layer 30.

In one embodiment, the bottom surface of the groove 41 is a plane. The bottom surface of the groove 41 refers to the surface of the groove 41 away from the substrate 10. By setting the bottom surface of the groove 41 to be a plane, the surface of the subsequently formed protruding structure away from the substrate 10 can be a plane, and the surface of the solder column finally formed away from the substrate 10 can be relatively flat. Since the surface flatness of the solder column away from the substrate 10 is better, when the signal processor is welded to the solder column, even if there is a deviation in the alignment of the electrode of the signal processor and the corresponding solder column, the electrode of the signal processor can be ensured to contact with the surface of the solder column away from the substrate 10, which can improve the reliability of the welding between the electrode of the signal processor and the corresponding solder column and prevent the problem of cold soldering.

In some embodiments, the groove 41 may be in a truncated cone shape.

In one embodiment, the distance between the geometric centers of the bottom surfaces of adjacent grooves 41 in the imprint template 40 may be submicron. For example, the distance between the geometric centers of the bottom surfaces of adjacent grooves 41 is less than or equal to 5 μm. The imprint template may be processed using a high-precision processing equipment so that the distance between adjacent grooves in the imprint template 40 is smaller. When the groove 41 is truncated cone-shaped, the bottom surface of the groove 41 is circular, and its geometric center is also the center of the circle. In some embodiments, the distance between the geometric centers of adjacent grooves 41 may be 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc.

In one embodiment, the depth of the groove 41 is greater than or equal to 3 μm. In the process of etching the solder film layer 30, the etching speed of each part of the surface of the solder film layer 30 can be basically the same, so the height of the solder column finally obtained is basically the same as the depth of the groove 41, that is, the height of the solder column is greater than or equal to 3 μm. In this way, after the photodetector and the signal processor are welded, the height of the gap between the functional layer of the photodetector and the signal processor is greater than or equal to 3 μm, which facilitates the injection of adhesive material into the gap between the functional layer of the photodetector and the signal processor. After the adhesive material is cured, the strength of the photodetector and the signal processor can be improved.

In one embodiment, the ratio of the maximum width of the bottom surface of the groove 41 to the distance between the geometric centers of the bottom surfaces of adjacent grooves 41 is less than or equal to 90%. When the bottom surface of the groove is circular, the maximum width of the bottom surface of the groove is the diameter of the bottom surface. In the process of etching the solder film layer 30, the etching speed of each part of the surface of the solder film layer 30 can be basically the same, then the shape and size of the top surface of the obtained solder column (the surface away from the substrate) are basically the same as the shape and size of the bottom surface of the groove 41, and the distance between the geometric centers of the bottom surfaces of adjacent grooves 41 is basically the same as the distance between the geometric centers of the top surfaces of adjacent solder columns, that is, the ratio of the maximum width of the top surface of the solder column to the distance between the geometric centers of the top surfaces of adjacent solder columns is less than or equal to 90%. The signal processor soldered to the photodetector includes a plurality of conductive parts, and the distance between the geometric centers of the surfaces of adjacent conductive parts is basically the same as the distance between the geometric centers of the top surfaces of adjacent solder columns, then the ratio of the maximum width of the top surface of the solder column of the photodetector to the distance between the geometric centers of the surfaces of adjacent conductive parts in the signal processor is less than or equal to 90%. In this way, when the photodetector and the signal processor are soldered, the problem of short circuit caused by electrical connection between the same solder column of the photodetector and two adjacent conductive parts of the signal processor can be avoided.

In one embodiment, as shown in FIG3 , the depth of the groove 41 of the imprint template 40 is less than the thickness of the solder film layer 30. With such a configuration, after the imprint template 40 embosses the solder film layer 30, it can be ensured that the portion of the solder film layer 30 that enters each groove 41 fills the groove 41, thereby ensuring that the shapes and sizes of the multiple protruding structures 31 formed are substantially the same, thereby helping to improve the uniformity of the morphology of the solder column formed subsequently.

In step 140, the imprinting template is pressurized so that the imprinting template partially enters the solder film layer, so as to squeeze part of the material of the solder film layer into the groove to form a protruding structure.

In this step, after the imprint template 40 is pressurized, the imprint template applies force to the solder film layer, so that part of the material of the solder film layer 30 is squeezed and enters the groove 41 of the imprint template 40. Through this step, a third intermediate structure as shown in FIG4 can be obtained. As shown in FIG4, part of the material of the solder film layer 30 enters the groove 41 to form a convex structure 31, and the convex structure 31 in each groove 41 fills the groove 41 respectively.

In one embodiment, the preparation method further includes the following steps: while the step of pressurizing the imprint template, the solder film layer is heated, and the heating temperature is respectively lower than the melting point of the material of the solder film layer and the melting point of the material of the imprint template. By heating the solder film layer, the ductility of the solder film layer can be improved, which is more conducive to the material of the solder film layer entering the groove and helping the material of the solder film layer to fill the groove; by setting the heating temperature lower than the melting point of the solder film layer and the melting point of the material of the imprint template, it is possible to avoid the fusion of the material of the solder film layer and the material of the imprint template, which makes it difficult to separate the imprint template and the solder film layer.

In one embodiment, as shown in Fig. 4, the solder film layer 30 is partially located between the protruding structure 31 and the functional layer 20. The imprint template 40 cannot divide the solder film layer into a plurality of spaced structures, so after step 140, the portion of the solder film layer between the protruding structure 31 and the functional layer is a continuous film layer.

In step 150, the imprint template is separated from the solder film layer, and the solder film layer is etched, at least the portion of the solder film layer between adjacent protruding structures is etched away to obtain a plurality of solder columns arranged at intervals, and the solder columns are electrically connected to the photoelectric detection element.

The fourth intermediate structure shown in FIG. 5 can be obtained by separating the imprint template from the solder film layer.

In one embodiment, the step of separating the imprint template from the solder film layer is performed after the temperature of the solder film layer and the imprint template drops to room temperature. After the solder film layer returns to room temperature, the shape of the protruding structure 31 is fixed and is not easily deformed. After the imprint template is separated from the plastic film layer, the shape of the protruding structure 31 does not change.

In one embodiment, the imprinting template may be separated from the solder film layer by applying force to the imprinting template.

In one embodiment, the step of etching the solder film layer comprises the following process: etching the surface of the solder film layer away from the substrate, and the etching speed of each part of the surface of the solder film layer away from the substrate is substantially the same. The surface of the solder film layer 30 includes the surface of the solder film layer 30 located between adjacent protruding structures 31 away from the substrate 10, the surface of the protruding structure 31 away from the substrate 10, and the side of the protruding structure 31. Since the etching speed of each part of the surface of the solder film layer 30 is substantially the same during the etching of the solder film layer 30, after the etching of the solder film layer 30 is completed, the shape and size of the solder column finally obtained are substantially the same as the protruding structure 31, that is, the shape and size of the solder column are substantially the same as the shape and size of the groove 41 of the imprint template 40. Therefore, the groove 41 of the imprint template 40 can be made according to the shape and size of the solder column to be formed, so as to prepare the solder column of the desired size and shape using the imprint template.

The photoelectric detector shown in Fig. 6 can be obtained through step 150. As shown in Fig. 6, in the photoelectric detector, the solder film layer 30 includes a plurality of solder pillars 32 arranged at intervals, and the size and shape of each solder pillar 32 are substantially the same.

In one embodiment, the distance between the geometric centers of the orthographic projections of adjacent solder pillars 32 on the substrate 10 is less than or equal to 5 μm. The distance between the geometric centers of the orthographic projections of adjacent solder pillars 32 on the substrate 10 is the same as the distance between the geometric centers of the bottom surfaces of adjacent grooves 41 of the imprint template 40. In some embodiments, the solder pillars 32 are truncated cone-shaped, and the orthographic projection of the solder pillars 32 on the substrate 10 is a circle, and its geometric center is also the center of the orthographic projection. In some embodiments, the distance between the geometric centers of the orthographic projections of adjacent solder pillars 32 on the substrate 10 may be 0.1 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc.

In one embodiment, the height of the solder pillar 32 is greater than or equal to 3 μm.

In one embodiment, a ratio of a maximum width of a top surface of the solder pillar 32 to a distance between geometric centers of top surfaces of adjacent solder pillars 32 is less than or equal to 90%.

In one embodiment, the step of etching the surface of the solder film layer away from the substrate includes the following process: etching the surface of the solder film layer using an ion beam etching process. The ion beam etching process uses the principle of glow discharge to decompose the inert gas into ions, and the ions bombard the surface of the sample to be etched under the acceleration of the electric field to achieve the etching effect. Etching the solder film layer using the ion beam etching process can control the side wall profile of the solder column 32, which helps to improve the uniformity of the size of the obtained solder column 32, and can make the height of each solder column 32 basically the same, and make the morphology of each solder column 32 more consistent, thereby helping to improve the welding effect of the photodetector and the signal processor, and ensure the reliability of the electrical connection between the photodetector and the signal processor. The preparation method of the photodetector provided in the embodiment of the present application, through the process of imprinting using an imprinting template and the ion beam etching process, can make the distance between the geometric centers of the positive projections of adjacent solder columns 32 on the substrate 10 in the prepared solder column 32 smaller (for example, reaching the submicron level), and at the same time ensure the uniformity of the morphology of the solder column.

In one embodiment, each of the solder pillars is electrically connected to a photodetection element.

In one embodiment, the photodetector is an infrared light detector.

An embodiment of the present application further provides a photoelectric detection system, which includes the photoelectric detector described in any of the above embodiments.

In one embodiment, the photoelectric detection system further includes a signal processor, which includes a plurality of electrodes, each electrode being soldered to a solder column of the photoelectric detector; the signal processor is used to collect the electrical signal output by the photoelectric detection system.

In one embodiment, the photoelectric detection system further includes a housing, and the photoelectric detector is fixed in the housing.

In one embodiment, the signal processor may also perform data processing on the collected electrical signals to generate images.

In one embodiment, the photoelectric detection system further comprises a display. The display can display the image generated by the processor.

In one embodiment, the photoelectric detection system can be used in fields such as medical treatment, security inspection, and non-destructive industrial inspection.

It should be noted that in the accompanying drawings, the sizes of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it may be directly on the other element, or there may be an intermediate layer. In addition, it is understood that when an element or layer is referred to as being "under" another element or layer, it may be directly under the other element, or there may be more than one intermediate layer or element. In addition, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it may be the only layer between the two layers or two elements, or there may also be more than one intermediate layer or element. Similar reference numerals throughout the text indicate similar elements.

Those skilled in the art will readily appreciate other embodiments of the present application after considering the description and practicing the contents disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The description and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims (10)

1. A method of fabricating a photodetector, comprising:

Providing a substrate with a functional layer, wherein the functional layer comprises a plurality of photoelectric detection elements arranged in an array;

Forming a solder film layer on the surface of the functional layer far away from the substrate, wherein the solder film layer covers the surface of the functional layer far away from the substrate;

Placing an imprinting template on one side of the solder film layer away from the substrate; a plurality of grooves which are distributed at intervals are formed in one side, facing the solder film layer, of the imprinting template;

pressurizing the imprinting template to enable the imprinting template to partially enter the solder film layer so as to squeeze part of the material of the solder film layer into the groove to form a protruding structure; the part of the solder film layer between the convex structure and the functional layer is a continuous film layer;

and separating the imprinting template from the solder film layer, etching the surface of the solder film layer far away from the substrate, wherein the etching speed of the surface of the solder film layer far away from the substrate is basically the same, so as to obtain a plurality of solder columns which are distributed at intervals, and the solder columns are electrically connected with the photoelectric detection element.

2. The method of manufacturing a photodetector of claim 1, wherein said method of manufacturing further comprises: and heating the solder film layer while pressurizing the imprinting template, wherein the heating temperature is respectively smaller than the melting point of the material of the solder film layer and the melting point of the material of the imprinting template.

3. The method for manufacturing a photodetector according to claim 1, wherein etching the surface of the solder film layer away from the substrate comprises: and etching the surface of the solder film layer far away from the substrate by adopting an ion beam etching process.

4. The method of claim 1, wherein the material of the imprint template is a nonmetallic material.

5. The method of claim 1, wherein the material of the imprint template comprises at least one of silicon oxide and silicon nitride.

6. The method of manufacturing a photodetector according to claim 1, wherein the cross-sectional area of the groove gradually increases in a direction directed toward the substrate by the imprint template; and/or the number of the groups of groups,

The bottom surface of the groove is a plane.

7. The method of manufacturing a photodetector according to claim 1, wherein a distance between geometric centers of bottom surfaces of adjacent grooves is less than or equal to 5 μm; and/or the number of the groups of groups,

The depth of the groove is more than or equal to 3 mu m; and/or the number of the groups of groups,

The ratio of the maximum width of the bottom surface of the groove to the distance between the geometric centers of the bottom surfaces of adjacent grooves is less than or equal to 90%.

8. The method of manufacturing a photodetector of claim 1, wherein a distance between geometric centers of orthographic projections of adjacent solder columns on the substrate is less than or equal to 5 μm.

9. The method of manufacturing a photodetector of claim 1, wherein the depth of said recess is less than the thickness of said solder film layer.

10. The method of manufacturing a photodetector of claim 1, wherein said solder film layer is indium.