Single-photon detector, manufacturing method thereof and detection device

Abstract

The embodiment of the invention discloses a single-photon detector, a manufacturing method thereof and a detection device, relates to the technical field of semiconductors, and aims to solve the problem of unstable performance of the single-photon detector. The manufacturing method of the single-photon detector comprises the steps of providing a substrate which comprises a substrate and a first material layer formed on the surface of the substrate, doping the first material layer, forming an epitaxial layer, forming at least one diode doped region in the epitaxial layer, forming at least one first electrode, removing the substrate, and forming at least one second electrode.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a single photon detector and a manufacturing method and a detection device thereof. Background Art

[0002] A single-photon detector is a photoelectric detector that can detect a single photon and has the characteristics of high sensitivity.

[0003] At present, in order to make a denser pixel array, the electrodes of the single-photon detector are usually set on both sides of the epitaxial layer to achieve double-sided power supply. However, the electrodes are set on both sides of the epitaxial layer. Due to structural limitations during the manufacturing process, the impurities doped in the epitaxial layer are difficult to be fully activated, making the device performance unstable. Summary of the invention

[0004] The embodiments of the present disclosure provide a single-photon detector and a manufacturing method and a detection device thereof, aiming to solve the problem of unstable performance of the single-photon detector.

[0005] To achieve the above objectives, the embodiments of the present disclosure adopt the following technical solutions:

[0006] In a first aspect, a method for manufacturing a single-photon detector is provided. The manufacturing method comprises: providing a substrate, the substrate comprising a substrate and a first material layer formed on one side of the substrate. Doping the first material layer. Forming an epitaxial layer, the epitaxial layer being located on a surface of the first material layer away from the substrate. Forming at least one diode doping region in the epitaxial layer. Forming at least one first electrode, the first electrode being located on a side of the epitaxial layer away from the first material layer, the first electrode being connected to one of the diode doping regions in the at least one diode doping region. Removing the substrate. Forming at least one second electrode, the second electrode being located on a side of the first material layer away from the epitaxial layer, the second electrode being connected to the first material layer.

[0007] In the disclosed embodiment, the first material layer of the substrate is first doped, and the doping annealing process heats the first material layer to repair the lattice defects of the first material layer generated during the doping process, and allows the implanted impurity atoms to diffuse in the first material layer to activate the impurity atoms and reduce the contact resistance between the electrode and the first material layer. After the first material layer is doped, a diode doping region is formed in the epitaxial layer, so that the impurity ions of the first material layer are fully activated, and the high temperature during the annealing process of the first material layer will not destroy the structure of the diode doping region, thereby improving the stability of the single-photon detector.

[0008] In some embodiments, the substrate further includes a second material layer, the second material layer being located between the substrate and the first material layer.

[0009] In some embodiments, removing the substrate includes: removing a portion of the substrate by a chemical mechanical polishing process, and removing the remaining portion of the substrate by an etching process, using the second material layer as an etching stop layer.

[0010] In some embodiments, after removing the substrate, the second material layer is removed.

[0011] In some embodiments, in forming the epitaxial layer, the thickness of the epitaxial layer is greater than or equal to the thickness of the first material layer.

[0012] In some embodiments, the diode doping region includes a first doping portion and a second doping portion, and the first doping portion is in contact with the second doping portion. Before forming at least one first electrode, the method for manufacturing a single-photon detector further includes: forming a first electrode contact region in the first doping portion. The doping concentration of the first electrode contact region is greater than the doping concentration of the first doping portion. In forming at least one first electrode, at least one first electrode is in contact with the first electrode contact region.

[0013] In some embodiments, forming at least one first electrode includes: forming an interlayer dielectric layer, the interlayer dielectric layer being located on a surface of the epitaxial layer away from the first material layer. Forming a through hole on the interlayer dielectric layer, the through hole penetrating the interlayer dielectric layer and exposing the diode doping region. Forming the first electrode in the through hole.

[0014] In some embodiments, before forming at least one second electrode, a trench isolation structure is formed. Forming the trench isolation structure includes: forming a trench, the trench is located at the periphery of the diode doping region, the dimension of the trench along a first direction in the epitaxial layer is less than or equal to the dimension of the epitaxial layer along the first direction, and the first direction is the thickness direction of the first material layer. Filling the trench with an isolation material to form the trench isolation structure.

[0015] In some embodiments, the substrate further includes a second material layer located between the substrate and the first material layer. Forming a groove includes: forming an opening on the second material layer, the opening being located at the periphery of the diode doping region. Doping the first material layer and the epitaxial layer from the opening to form a second contact region. In the second contact region, a groove is formed. The size of the groove in the second direction is smaller than the size of the opening in the second direction, and the second direction is perpendicular to the first direction.

[0016] In some embodiments, forming the epitaxial layer further includes: doping the epitaxial layer. The doping concentration of the epitaxial layer is less than the doping concentration of the first material layer.

[0017] In a second aspect, a single-photon detector is provided. The single-photon detector is manufactured by the manufacturing method of the single-photon detector described in any of the above embodiments, and includes: a first material layer, an epitaxial layer, at least one first electrode and at least one second electrode. The first material layer has a first doping type. The epitaxial layer is located on the surface of the first material layer, and at least one diode doping region is arranged in the epitaxial layer. The first electrode is located on a side of the epitaxial layer away from the first material layer, and the first electrode is connected to the diode doping region. The second electrode is located on a side of the first material layer away from the epitaxial layer, and the second electrode is connected to the first material layer.

[0018] The beneficial effects that can be achieved by the method for manufacturing a single-photon detector provided in the embodiments of the present disclosure can be referred to the beneficial effects of the manufacturing method described above, and will not be described in detail here.

[0019] In some embodiments, the dimension of the trench isolation structure of the single photon detector in the epitaxial layer along a first direction is less than or equal to the dimension of the epitaxial layer along the first direction. The first direction is the thickness direction of the first material layer.

[0020] In a third aspect, a detection device is provided, which includes: at least one single-photon detector, which is any of the single-photon detectors in the above embodiments.

[0021] The beneficial effects that can be achieved by the detection device provided by some embodiments of the present disclosure can be referred to the beneficial effects of the manufacturing method described above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings required to be used in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not limitations on the actual size of the products involved in the embodiments of the present disclosure, the actual process of the method, etc.

[0023] Figure 1A It is a structural schematic diagram of a single photon detector in the related art;

[0024] Figure 1B It is a structural schematic diagram of another single photon detector in the related art;

[0025] Figure 2 A flow chart of a method for making a single photon detector provided for some embodiments of the present disclosure;

[0026] Figure 3-15B is a structural diagram corresponding to each step in a method for manufacturing a single-photon detector according to some embodiments;

[0027] Fig.16 is a structural diagram of a single photon detector according to some embodiments;

[0028] Fig.17 is a block diagram of a detection device according to some embodiments. DETAILED DESCRIPTION

[0029] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0030] In the description of the present disclosure, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present disclosure.

[0031] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as an open, inclusive meaning, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics described may be included in any one or more embodiments or examples in any appropriate manner.

[0032] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0033] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0034] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0035] In the context of the present disclosure, the meanings of “on,” “over,” and “over” should be interpreted in the broadest manner, so that “on” means not only “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “over” or “above” means not only “above” or “over” something, but also includes the meaning of “above” or “over” something without intervening features or layers therebetween (i.e., directly on something).

[0036] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0037] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within the acceptable deviation range, wherein the acceptable deviation range is determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism may be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity may also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality may be, for example, the difference between the two equalities is less than or equal to 5% of either one.

[0038] Figure 1A Schematic diagram of the structure of a single photon detector in the related art. Figure 1B It is a schematic diagram of the structure of another single photon detector in the related technology.

[0039] A single photon avalanche diode (SPAD) is a solid-state photodetector device that achieves photodetection based on a reverse bias voltage exceeding the breakdown region of a PN junction. In a single photon avalanche diode, the PN junction is reverse biased at a voltage higher than the breakdown voltage, and an avalanche current is generated under the action of the internal photoelectric effect (the emission of electrons or another carrier when a material is hit by a photon). Using a single photon avalanche diode, very low signal intensities, such as down to a single photon level, can be detected. Single photon detectors based on single photon avalanche diodes can be used in highly sensitive photon capture environments, such as in fluorescence imaging, 3D imaging and other fields.

[0040] Currently, there are two ways to set up the electrodes of single-photon detectors. The first setting is shown in Figure 1A , cathode E1 and anode E2 are set on the same side of the device. In order to avoid the performance degradation of the device caused by the connection between the cathode and cathode, the cathode and cathode need to be isolated, or leave enough spacing, or set a guard ring between the cathode and cathode. These measures increase the size of the single-photon detector and severely limit the application range of the single-photon detector. With the development of single-photon detectors, it is necessary to make pixel arrays with higher density. Therefore, the second setting is usually adopted, see Figure 1B The cathode E1 and the anode E2 are arranged on both sides of the device, and the positive and negative electrodes are separated as much as possible to avoid connection between the positive and negative electrodes, so as to realize double-sided power supply of the device.

[0041] The traditional method of making a double-sided powered single-photon detector is to first form a PN junction in the epitaxial layer, for example, the PN junction is close to the front of the epitaxial layer, and then dope the side of the epitaxial layer away from the PN junction (i.e., the back of the epitaxial layer), with one electrode in contact with the PN junction and the other electrode in contact with the back of the epitaxial layer. In the process of doping the epitaxial layer to form a PN junction, ion implantation is performed, followed by laser annealing. However, laser annealing usually cannot fully activate impurities, which can significantly affect the uniformity of device performance, causing the single-photon detector to be short-circuited, or the device performance to be unstable, affecting the detection efficiency.

[0042] In order to solve the above technical problems, some embodiments of the present disclosure provide a method for manufacturing a single-photon detector, wherein a substrate is first doped, an epitaxial layer is formed on the substrate, a diode doping region is formed in the epitaxial layer, and electrodes are respectively arranged on both sides of the epitaxial layer.

[0043] Figure 2 A flow chart of a method for manufacturing a single-photon detector provided for some embodiments of the present disclosure. Figure 3-15B It is a structural diagram corresponding to each step in the method for manufacturing a single photon detector according to some embodiments. It should be noted that, in this article, the first direction Z is the thickness direction of the single photon detector, and the second direction X is perpendicular to the first direction Z.

[0044] The following is a schematic illustration of a method for manufacturing a single-photon detector provided in some embodiments of the present disclosure with reference to the accompanying drawings.

[0045] In some embodiments, the single-photon detector includes at least one single-photon avalanche diode, and the manufacturing method of the single-photon detector introduced below may correspond to the manufacturing method of one single-photon avalanche diode or the manufacturing method of multiple single-photon avalanche diodes.

[0046] See also Figure 2 , and combined with Figure 3-15B The manufacturing method of the above-mentioned single-photon detector includes: S1-S10.

[0047] S1. Provide a substrate.

[0048] Figure 3 A structural diagram of a substrate is provided in a method for manufacturing a single-photon detector according to some embodiments.

[0049] See also Figure 3 , the base includes a substrate 30 and a first material layer 10 formed on one side of the substrate 30. The first material layer 10 is on the substrate 30, and the thickness direction of the first material layer 10 is the thickness direction of the single-photon detector, that is, the first direction Z is the thickness direction of the first material layer 10. The substrate 30 may include, for example, a single-layer structure, and its material may include a combination of silicon (for example, single-crystal silicon), silicon germanium (SiGe), gallium arsenide (GaAs), germanium (Ge), and other suitable materials. The material of the first material layer 10 may include a combination of silicon (for example, single-crystal silicon), silicon germanium (SiGe), gallium arsenide (GaAs), germanium (Ge), and other suitable materials. The material of the first material layer 10 and the material of the substrate 30 may be the same or different. Exemplarily, the materials of the first material layer 10 and the substrate 30 are both silicon.

[0050] For the convenience of the following description, the two opposite surfaces of the substrate are respectively referred to as the first surface 101 and the second surface 102, the first surface 101 is the side surface of the first material layer 10 away from the substrate 30, and the second surface 102 is the side surface of the substrate 30 away from the first material layer 10. It can be understood that the areas of the first surface 101 and the second surface 102 can be the same or different.

[0051] In some embodiments, see Figure 3 , the substrate also includes a second material layer 20. The second material layer 20 is located between the first material layer 10 and the substrate 30, that is, the first material layer 10, the second material layer 20 and the substrate 30 are stacked in sequence. The material of the second material layer 20 can be one or more combinations of silicon oxide and silicon nitride. The material of the second material layer 20 is different from that of the first material layer 10, and the material of the second material layer 20 is different from that of the substrate 30. Under the same process conditions, the etching rate of the substrate 30 is different from that of the second material layer 20. Exemplarily, the substrate is a silicon on insulator (SOI) substrate, the first material layer 10 is silicon, and the second material layer 20 is silicon dioxide (SiO 2 ), the substrate 30 is silicon.

[0052] S2. Doping the first material layer 10.

[0053] Figure 4 FIG. 4 is a structural diagram of doping a first material layer in a method for manufacturing a single-photon detector according to some embodiments.

[0054] See also Figure 4 , doping the first material layer 10, the doping annealing process will heat the first material layer 10 to repair the lattice defects of the first material layer 10 generated during the doping process, and allow the implanted impurity atoms to diffuse in the first material layer 10 to activate the impurity atoms and reduce the contact resistance between the electrode and the first material layer 10. The doping process is, for example, ion implantation or diffusion process. At this time, the first material layer 10 has a first doping type. The first doping type can be P-type or N-type. Exemplarily, ion implantation is performed on the first material layer 10 from the first surface 101, and the first material layer 10 is doped with elements such as boron (B), indium (In), and gallium (Ga) to form a uniform P-type semiconductor. Exemplarily, ion implantation is performed on the first material layer 10 from the first surface 101, and the first material layer 10 is doped with elements such as phosphorus (P), arsenic (As), and antimony (Sb) to form a uniform N-type semiconductor. At this time, the first surface 101 is the front side of the substrate, and the front side of the substrate faces upward, which is convenient for the doping process of the first material layer 10.

[0055] S3. Forming an epitaxial layer 50.

[0056] Figure 5 FIG. 4 is a structural diagram of forming an epitaxial layer in a method for manufacturing a single-photon detector according to some embodiments.

[0057] See also Figure 5 , epitaxial growth is performed on a surface of the first material layer 10 away from the substrate 30 to form an epitaxial layer 50 , that is, the epitaxial layer 50 is located on the first surface 101 .

[0058] In some embodiments, the epitaxial layer 50 is doped, for example, by ion implantation or diffusion process. The epitaxial layer 50 and the first material layer 10 have the same doping type, for example, the first doping type of the epitaxial layer 50 and the first material layer 10 are both P type.

[0059] In some embodiments, the thickness of the epitaxial layer 50 is greater than or equal to the thickness of the first material layer 10. Compared with doping the entire epitaxial layer 50, under the same process conditions, the doping impurity atoms of the thinner first material layer 10 are more evenly distributed, the doping concentration is higher, the electrode contacts the first material layer 10, the resistivity is lower, and a good ohmic contact is formed between the electrode and the first material layer.

[0060] When a single-photon detector is in use, part of the contribution to light detection is generated by the diffusion of carriers from the neutral region into the multiplication region. The diffusion length of the carrier is related to its lifetime. The longer the carrier lifetime, the longer the diffusion length, the more carriers there are in the multiplication region, and the higher the detection efficiency of the single-photon detector. However, the carrier lifetime is inversely proportional to the doping concentration. The higher the doping concentration, the lower the carrier lifetime, the more difficult it is to diffuse into the multiplication region, and the lower the light propagation efficiency.

[0061] In some embodiments, the lifetime of carriers is increased by controlling the doping concentration of the epitaxial layer 50. The doping concentration of the epitaxial layer 50 is less than the doping concentration of the first material layer 10. For example, the doping concentration of the first material layer 10 may be heavily doped, and the doping concentration of the epitaxial layer may be lightly doped, medium doped, or reverse doped. For example, the doping concentration of the first material layer 10 is greater than 1×10 19 cm -3 , the doping concentration of the epitaxial layer 50 is 1×10 13 cm -3 —1×10 15 cm -3 It is understandable that the doping concentration of the epitaxial layer 50 only needs to be greater than the doping concentration of the first material layer 10 , and the embodiments of the present disclosure do not limit the specific doping concentrations of the epitaxial layer 50 and the first material layer 10 .

[0062] S4. Forming a diode doping region 51.

[0063] Figure 6 The structure diagram of forming a diode doping region in a method for manufacturing a single photon detector according to some embodiments. The single photon detector includes at least one diode doping region, and the figure shows only one diode doping region as an example.

[0064] See also Figure 6, at least one diode doping region 51 is formed in the epitaxial layer 50. One diode doping region 51 corresponds to one single photon avalanche diode. When the single photon detector includes one single photon avalanche diode, one diode doping region 51 is formed in the epitaxial layer 50; when the single photon detector includes multiple single photon avalanche diodes, multiple diode doping regions 51 are formed in the epitaxial layer 50, and the multiple diode doping regions 51 are arranged in an array, and the arrangement direction of the multiple diode doping regions 51 is parallel to the first surface 101.

[0065] Exemplarily, elements such as boron, indium, and gallium can be doped on the epitaxial layer 50 to form a uniform P-type semiconductor; elements such as phosphorus, arsenic, and antimony can be doped on the epitaxial layer 50 to form a uniform N-type semiconductor. The above-mentioned doping process is, for example, an ion implantation process or a diffusion process. In this way, the doped portion of the epitaxial layer 50 forms a first doping portion 511 and a second doping portion 512, and the remaining portion serves as a main body 52. ​​At this time, the first doping portion 511 and the second doping portion 512 form a diode doping region 51. That is, the diode doping region 51 includes a first doping portion 511 and a second doping portion 512. The first doping portion 511 and the second doping portion 512 are located inside the epitaxial layer 50.

[0066] The first doping portion 511 may be a single-layer structure, or the first doping portion 511 may be a multi-layer structure including a plurality of first sub-doping layers of the same doping type, and the plurality of first sub-doping layers are stacked.

[0067] The second doping portion 512 may be a single-layer structure, or the second doping portion 512 may be a multi-layer structure including a plurality of second sub-doping layers of the same doping type, and the plurality of second sub-doping layers are stacked.

[0068] The first doping portion 511 is in contact with the second doping portion 512, and at least the surface of the first doping portion 511 is exposed. Figure 6 , the diode doping region 51 can be vertically stacked, specifically, the first doping portion 511 and the second doping portion 512 are stacked. For example, the first doping portion 511 is located on the side of the second doping portion 512 away from the first surface 101. The surface of the first doping portion 511 away from the second doping portion 512 forms the third surface 103, so that the third surface 103 is exposed on the side of the epitaxial layer 50 away from the first surface 101, and can receive incident photons to achieve the function of photon detection.

[0069] The embodiment of the present disclosure is illustrated by taking the first doping portion 511 and the second doping portion 512 of the diode doping region 51 as being vertically stacked. Those skilled in the art should understand that the diode doping region 51 may also be laterally adjacent, in which case the arrangement direction of the first doping portion 511 and the second doping portion 512 is parallel to the first surface 101. The diode doping region 51 may also be obliquely adjacent, in which case the arrangement direction of the first doping portion 511 and the second doping portion 512 is at an acute angle to the first surface 101. The diode doping region 51 may also be a second doping portion 512 wrapping the first doping portion 511.

[0070] The first doping portion 511 and the second doping portion 512 form a PN junction, that is, the first doping portion 511 and the second doping portion 512 form a depletion region. It can be understood that when the first doping portion 511 and the second doping portion 512 form a PN junction, the doping type of the first doping portion 511 is different from the doping type of the second doping portion 512, for example, the second doping portion 512 has a first doping type, and the first doping portion 511 has a second doping type. When the first doping type is P-type, the second doping type is N-type; when the first doping type is N-type, the second doping type is P-type. The embodiment of the present disclosure is illustrated by taking the first doping type as P-type and the second doping type as N-type as an example. It can be understood that the first doping type as N-type and the second doping type as P-type are also applicable to the embodiment of the present disclosure. Exemplarily, the first doping portion 511 is N-type, the second doping portion 512 is P-type, and the main body 52 is P-type.

[0071] In some embodiments, before forming the diode doping region 51, the epitaxial layer 50 is doped as a whole. When forming the diode doping region 51, a portion of the epitaxial layer 50 is doped again to form a first doping portion 511, and another portion of the epitaxial layer is doped to form a second doping portion 512. At this time, the main body 52 is the remaining portion of the epitaxial layer 50 that has not been doped again. The doping concentrations of the first doping portion 511 and the second doping portion 512 are greater than the doping concentration of the main body 52 to increase the lifetime of carriers. Exemplarily, the doping concentration of the first doping portion 511 is heavily doped, the doping concentration of the second doping portion 512 is also heavily doped, and the doping concentration of the main body 52 is lightly doped.

[0072] In the embodiment of the present disclosure, after the first material layer 10 is doped, a diode doping region 51 is formed in the epitaxial layer 50, so that the high temperature of the first material layer 10 during the annealing process will not destroy the structure of the diode doping region 51; and the impurity ions in the first material layer 10 are fully activated, thereby improving the performance uniformity of the single-photon detector, thereby improving the stability of the formed single-photon detector and improving the detection efficiency.

[0073] S5 (optional): forming a first electrode contact region 513 .

[0074] Figure 7 FIG. 4 is a structural diagram of forming a first electrode contact region in a method for manufacturing a single-photon detector according to some embodiments.

[0075] See also Figure 7 , a first electrode contact region 513 is formed in the first doped portion 511 of the diode doped region 51. The first electrode contact region 513 is formed in the first doped portion 511, and illustratively, the orthographic projection of the first electrode contact region 513 on the third surface 103 is covered by the orthographic projection of the first doped portion 511 on the third surface 103. Also illustratively, the orthographic projection of the first electrode contact region 513 on the third surface 103 coincides with the orthographic projection of the first doped portion 511 on the third surface 103.

[0076] The first electrode contact region 513 may be formed by performing ion implantation in the corresponding region of the first doped portion 511 through a mask and activating the implanted ions. The doping type of the first electrode contact region 513 is the same as the doping type of the first doped portion 511, and the doping concentration of the first electrode contact region 513 is greater than the doping concentration of the first doped portion 511, so that the resistance of the first electrode contact region 513 is less than the resistance of the first doped portion 511, so that the first electrode 60 formed subsequently forms a good ohmic contact with the first doped portion 511 through the first electrode contact region 513.

[0077] In some other implementations, the first electrode contact region 513 may not be formed in the first electrode doping portion 511 , and after the diode doping region 51 is formed, step S6 is directly performed to form the first electrode 60 .

[0078] S6. Forming the first electrode 60.

[0079] Figure 8 FIG. 4 is a structural diagram of forming a first electrode in a method for manufacturing a single-photon detector according to some embodiments.

[0080] See also Figure 8 At least one first electrode 60 is formed on the side of the epitaxial layer 50 away from the first material layer 10, and the first electrode 60 is connected to the diode doping region 51. At this time, the side of the epitaxial layer 50 away from the substrate 30 is the front side of the device, and the side of the substrate 30 away from the epitaxial layer 50 is the back side of the device.

[0081] The material of the first electrode 60 is a conductive material, including one or more combinations of metals (for example, titanium (Ti), tantalum (Ta), chromium (Cr), tungsten (W), etc.), metal compounds (for example, titanium nitride (TiNx), tantalum nitride (TaNx), chromium nitride (CrNx), tungsten nitride (WNx), etc.) and metal alloys (for example, TiSixNy, TaSixNy, CrSixNy, WSixNy, etc.), or other suitable materials.

[0082] In some examples, the first electrode 60 is in contact with the diode doping region 51. One first electrode 60 is in contact with one diode doping region 51, and the first electrode 60 corresponds to the diode doping region 51 one by one, that is, the number of the first electrodes 60 is the same as the number of the diode doping regions 51. Specifically, the first electrode 60 is in contact with the first doping portion 511. Exemplarily, the bottom of the first electrode 60 is in contact with the first electrode contact region 513 in the first doping portion 511, so that a good ohmic contact is formed between the first electrode 60 and the first doping portion 511. Exemplarily, there is no first electrode contact region 513 in the first doping portion 511, and the first electrode 60 is in direct contact with the first doping portion 511. Exemplarily, at least one first electrode 60 is in contact with the first electrode contact region 513 of the corresponding first doping portion 511, and the remaining first electrodes 60 are in direct contact with the corresponding first doping portion 511.

[0083] In some other examples, the first electrode 60 is connected to the diode doping region 51 through a relay electrode. One first electrode 60 corresponds to a plurality of diode doping regions 51 , that is, the number of the first electrodes 60 is less than the number of the diode doping regions 51 .

[0084] For example, the first electrode 60 may be simultaneously connected to all the diode doping regions 51 through relay electrodes. In this case, the single-photon detector forms one first electrode 60 .

[0085] For example, a first electrode 60 can be connected to multiple diode doping regions 51 through relay electrodes, another first electrode 60 can be connected to other diode doping regions 51 through relay electrodes, all diode doping regions 51 are respectively connected to the first electrode 60 through relay electrodes, and one relay electrode is in contact with one diode doping region 51. At this time, the single-photon detector forms multiple second electrodes 60.

[0086] In some other examples, one first electrode 60 may be in contact with one diode doping region 51 , and another first electrode 60 may be connected to a plurality of diode doping regions 51 through a relay electrode.

[0087] The steps of forming the first electrode 60 include:

[0088] S61 , forming an interlayer dielectric layer 90 .

[0089] Fig.9A FIG. 4 is a structural diagram of forming an interlayer dielectric layer in a method for manufacturing a single-photon detector according to some embodiments.

[0090] See also Fig.9A, a dielectric material may be deposited on the side of the epitaxial layer 50 away from the substrate (i.e., the surface of the epitaxial layer 50 away from the first material layer 10) by using a thin film deposition process such as chemical vapor deposition (CVD), physical vapor deposition (PVD) or atomic layer deposition (ALD). The dielectric material may include, for example, polysilicon, silicon oxynitride, etc.

[0091] S62 , forming a through hole 91 in the interlayer dielectric layer 90 .

[0092] Fig. 9B FIG. 4 is a structural diagram of forming a through hole in a method for manufacturing a single-photon detector according to some embodiments.

[0093] See also Fig. 9B , a through hole 91 can be formed on the interlayer dielectric layer 90 by an etching method, the through hole 91 penetrates the interlayer dielectric layer 90 and exposes the diode doping region 51. Exemplarily, the through hole 91 exposes the first doping portion 511. Also exemplary, the through hole 91 exposes the first electrode contact region 513.

[0094] S63 , forming the first electrode 60 in the through hole 91 .

[0095] Fig. 9C FIG. 4 is a structural diagram of forming a first electrode in a through hole in a method for manufacturing a single-photon detector according to some embodiments.

[0096] See also Fig. 9C , a conductive material is filled in the through hole 91. The conductive material can be referred to in the above examples. A chemical-mechanical planarization (CMP) or etching process can be used to remove the conductive material on the upper surface of the interlayer dielectric layer 90, and the conductive material in the through hole 91 is retained to form the first electrode 60.

[0097] In some other implementations, S61 - S63 may be replaced by: directly forming the first electrode 60 on the epitaxial layer 50 by printing or other processes.

[0098] S7 . Remove the substrate 30 .

[0099] Fig.10 FIG. 4 is a structural diagram of a method for manufacturing a single-photon detector according to some embodiments in which the substrate 30 is removed.

[0100] In order to facilitate the removal of the substrate 30, the side of the substrate 30 away from the epitaxial layer 50 is turned upward. At this time, the front side of the device becomes the side of the substrate 30 away from the epitaxial layer 50, and the back side of the device becomes the side of the epitaxial layer 50 away from the substrate 30. The substrate 30 is removed from the front side of the device by CMP or etching process, see Fig.10 Compared with operating from the back of the device in step S6, removing the substrate 30 from the front of the device, CMP directly grinds from the front from top to bottom, or during the etching process, the etching liquid acts on the substrate 30 under the action of gravity, and there is no need to add a structure to lift the etching liquid, which helps to reduce the process difficulty.

[0101] The substrate further includes a second material layer 20, and the step of removing the substrate 30 includes:

[0102] S71 , thinning the substrate 30 by CMP.

[0103] Specifically, the CMP process is used from the side of the substrate 30 away from the first material layer 10 to grind the substrate 30 and remove a portion of the substrate 30. Compared with using an etching process to remove the entire substrate 30, first using a CMP process to thin it can save etching solution, shorten etching time, and improve manufacturing efficiency. In addition, the second material layer 20 plays a role in protecting the first material layer 10, preventing excessive grinding, making the surface of the first material layer 10 uneven, maintaining the uniformity of the thickness of the first material layer 10, and making the contact resistance of the second electrode formed subsequently uniform.

[0104] S72 , removing the remaining portion of the substrate 30 through an etching process, using the second material layer 20 as an etching stop layer.

[0105] Since the materials of the second material layer 20 and the substrate 30 are different, the second material layer 20 is used as an etching stop layer and will not be etched to the first material layer 10, thereby maintaining a uniform thickness of the first material layer 10. In this way, during the operation of the single-photon detector formed, the distances at which photogenerated carriers in different regions diffuse to the depletion region are consistent, thereby maintaining the stability of the performance of the single-photon detector.

[0106] In some embodiments, since the side of the first material layer 10 away from the substrate 30 faces upward when the substrate 30 is removed, before operating the substrate 30, a protective layer can be formed on the surface of one side of the epitaxial layer 50 where the first electrode 60 is provided, or a supporting substrate (not shown in the figure) can be temporarily bonded.

[0107] In some other implementations, S71 - S72 may be replaced by: directly removing the entire substrate 30 through a CMP process, or removing the entire substrate 30 through an etching process.

[0108] S8 (optional): remove the second material layer 20 .

[0109] Fig.11 A structural diagram of removing the second material layer in a method for manufacturing a single-photon detector according to some embodiments.

[0110] See also Fig.11 , the second material layer 20 can be removed by CMP or etching process. Since the second material layer 20 and the first material layer 10 are made of different materials, under the same process conditions, the etching speed of the first material layer 10 is different from the etching speed of the second material layer 20. Removing the second material layer 20 can reduce the device thickness, form a denser pixel array, and increase the application range of the single-photon detector.

[0111] In other implementations, if there is no second material layer 20 in the substrate, this step can be omitted.

[0112] In some other implementations, step S8 may be performed after step S9 or step S10, and the disclosed embodiment does not limit this. Exemplarily, after removing the substrate 30, the trench isolation structure 70 is directly formed, and then the second material layer 20 is removed to form the second electrode 80. Again exemplarily, after removing the substrate 30, the trench isolation structure 70 is formed, the second electrode 80 is formed, and then the second material layer 20 is removed.

[0113] S9 (optional): forming a trench isolation structure 70 .

[0114] Figure 12A-12B FIG. 5 is a diagram showing the steps of forming a trench isolation structure in a method for manufacturing a single photon detector according to some embodiments.

[0115] In the related art, the number of single photon avalanche diodes is arranged in an array to form a larger detection area. However, when the number of single photon avalanche diodes is arranged in an array, crosstalk is easily formed between adjacent single photon avalanche diodes.

[0116] In order to reduce crosstalk, a trench isolation structure 70 is formed in the step of making a single-photon detector. The trench isolation structure 70 is located at the periphery of the diode doping region 51. The trench isolation structure 70 can achieve optical isolation, that is, when multiple single-photon avalanche diodes are arranged in an array, the photons incident on one of the single-photon avalanche diodes can be measured only by the single-photon avalanche diode, and will not be measured by the adjacent single-photon avalanche diode, thereby avoiding crosstalk between adjacent single-photon avalanche diodes. It can be understood that the trench isolation structure 70 is located at the periphery of the diode doping region 51, which means that the orthographic projection of the trench isolation structure 70 on the first surface 101 does not overlap with the orthographic projection of the diode doping region 51 on the first surface 101.

[0117] The steps of forming the trench isolation structure 70 include:

[0118] S91, see Fig. 12A , forming a groove 71.

[0119] Exemplarily, the process of forming the trench 71 is an etching process.

[0120] The groove 71 is located at the periphery of the diode doping region 51, and extends from the surface of the first material layer 10 away from the epitaxial layer 50 to the epitaxial layer 50, that is, the groove 71 at least penetrates the first material layer 10. The first dimension h1 of the groove 71 in the epitaxial layer 50 along the first direction Z is less than or equal to the thickness H of the epitaxial layer 50. Specifically, the first dimension h1 of the groove 71 refers to the depth of the groove 71 in the epitaxial layer 50; the first dimension h1 of the groove 71 is equal to the thickness H of the epitaxial layer 50, which means that the groove 71 penetrates the epitaxial layer 50. It can be understood that the groove 71 is located at the periphery of the diode doping region 51 here, which means that the orthographic projection of the groove 71 on the first surface 101 does not overlap with the orthographic projection of the diode doping region 51 on the first surface 101.

[0121] Exemplarily, the trench 71 is a shallow isolation trench, and in this case, the first dimension h1 of the trench 71 is smaller than the thickness H of the epitaxial layer 50. The shallow isolation trench process is simple, mature, and easy to implement.

[0122] As another example, the trench 71 is a deep isolation trench and penetrates the epitaxial layer 50. The deep isolation trench has a good isolation effect.

[0123] It should be noted that the present disclosure does not limit the width of the groove 71. It is understandable that the larger the width of the groove 71, the better the isolation effect, but the larger the groove 71, the smaller the area of ​​the detection area. Therefore, those skilled in the art can select the width of the groove 71 according to needs. Here, the width of the groove 71 refers to the distance between the two sides of the groove 71 parallel to its extension direction on the orthographic projection of the first surface 101.

[0124] The groove 71 may include a plurality of groove units arranged at intervals. Those skilled in the art may arrange more groove units in the crosstalk-prone area and fewer groove units in other areas according to requirements.

[0125] S92, see Fig. 12B , an isolation material is filled in the trench 71 to form a trench isolation structure 70 .

[0126] The isolation material may be silicon dioxide, silicon nitride, polysilicon, or metal tungsten; the above isolation materials may be filled into the trench 71 through a deposition process.

[0127] The trench 71 is a shallow isolation trench, and the dimension h of the trench isolation structure 70 in the epitaxial layer 50 along the first direction Z is less than the thickness H of the epitaxial layer. The trench 71 is a deep isolation trench, and the dimension h of the trench isolation structure 70 in the epitaxial layer 50 along the first direction Z is equal to the epitaxial layer 50. At this time, the trench isolation structure 70 penetrates the epitaxial layer 50.

[0128] In some embodiments, before the isolation material is filled in the trench 71, a dielectric material is deposited on the bottom and sidewalls of the trench 71, and the dielectric material is a material with a dielectric constant exceeding 3.9. With a high dielectric constant, the charges in the dielectric are more easily polarized, resulting in easier movement of the charges in the dielectric, stronger conductivity, and reduced dark counts in the trench isolation structure 70.

[0129] Figure 13A-13C FIG. 5 is a diagram showing a step of forming a groove in a method for manufacturing a single photon detector according to some embodiments.

[0130] In some embodiments, the substrate further includes a second material layer 20, and the step of forming the groove 71 includes:

[0131] S911, see Fig.13A An opening (hereinafter referred to as a first opening) 21 is formed in the second material layer 20 .

[0132] Exemplarily, the process for forming the first opening 21 is an etching process. The first opening 21 penetrates the second material layer 20 and exposes the first material layer 10. The first opening 21 is located at the periphery of the diode doping region 51, that is, the orthographic projection of the first opening 21 on the first surface 101 does not overlap with the orthographic projection of the diode doping region 51 on the first surface 101. Since the material of the second material layer 20 is silicon oxide, the doping process cannot penetrate the second material layer 20. Therefore, in order to allow ions to be implanted to a predetermined depth, it is necessary to first set the first opening 21 on the second material layer 20 to expose the first material layer 10.

[0133] S912, see Fig. 13B , forming a second contact region 72.

[0134] The first material layer 10 and the epitaxial layer 50 are doped through the first opening 21. This process does not require the use of a mask, and the angle of ion implantation can be adjusted as needed during the implantation process. A second contact region 72 is formed within a predetermined depth on the surface of the first material layer 10 close to the second material layer 20 and facing the inside of the epitaxial layer 50, and a rapid thermal annealing is performed to activate the impurity ions.

[0135] S913, see Fig. 13C , in the second contact region 72 , a trench 71 is formed.

[0136] The groove 71 is located in the second contact area 72, and the dimension d of the groove 71 in the second direction X is smaller than the dimension D of the first opening 21 in the second direction X. That is to say, the second contact area 72 is separated from the side wall of the groove 71 to the epitaxial layer 50, so that some defects on the groove 71 cannot enter the working area of ​​the device, which helps to improve the device performance.

[0137] S10 , forming the second electrode 80 .

[0138] Fig.14 FIG. 4 is a structural diagram of forming a second electrode in a method for manufacturing a single-photon detector according to some embodiments.

[0139] See also Fig.14 At least one second electrode 80 is formed on a side of the first material layer 10 away from the epitaxial layer 50 . The second electrode 80 is connected to the first material layer 10 .

[0140] In some examples, the second electrode 80 contacts the first material layer 10 , and in this case, one second electrode 80 corresponds to one diode doping region 51 .

[0141] In some other examples, the second electrode 80 is connected to the first material layer 10 through a second relay electrode. In this case, one second electrode 80 corresponds to a plurality of diode doping regions 51 , and one diode doping region 51 corresponds to one second relay electrode.

[0142] In some other examples, a second electrode 80 may be in contact with the first material layer 10, and the second electrode 80 corresponds to a diode doping region 51; another second electrode 80 may be connected to the first material layer 10 through a relay electrode, and the second electrode 80 corresponds to another plurality of diode doping regions 51. The material of the second electrode 80 may refer to the material of the first electrode 60 described above, and will not be described in detail here.

[0143] In some examples, the second electrode 80 is in contact with the first material layer 10 . When the trench isolation structure 70 is formed in the step of manufacturing the single photon detector, the second electrode 80 is located inside the trench isolation structure 70 .

[0144] Figure 15A-15B FIG. 4 is another structural diagram of forming a second electrode in a method for manufacturing a single-photon detector according to some embodiments.

[0145] In some embodiments, the substrate further includes a second material layer 20, and the step of forming the second electrode 80 includes:

[0146] S101, see Fig.15A , forming a second opening 22 in the second material layer 20 .

[0147] Exemplarily, the process for forming the second opening 22 is an etching process. The second opening 22 penetrates the second material layer 20 and exposes the first material layer 10. The second opening 22 is located inside the trench isolation structure 70, that is, the orthographic projection of the second opening 22 on the first surface 101 does not overlap with the orthographic projection of the trench isolation structure 70 on the first surface 101.

[0148] In some other implementations, the first opening 21 and the second opening 22 can be formed in one etching process, which saves process and improves the manufacturing efficiency of the single-photon detector.

[0149] S102, see Fig. 15B , a second electrode 80 is formed in the second opening 22 .

[0150] Exemplarily, a conductive material is deposited in the second opening 22 to form the second electrode 80 .

[0151] In some embodiments, after forming the second electrode 80, a surface optical diffraction structure is further formed. The surface optical diffraction structure is located on the upper surface of the single-photon detector, close to the first doping portion 511 of the diode doping region 51. The light enters the multiplication region through the surface optical diffraction structure to gather the light. The surface optical diffraction structure is used to strengthen the optical path of the photon in the device to improve the detection efficiency. The surface optical diffraction structure can be a surface pyramid diffraction structure, a Fresnel diffraction lens, or a microlens.

[0152] The disclosed embodiment also provides a single photon detector, which is manufactured by any of the above methods.

[0153] Fig.16 is a structural diagram of a single photon detector according to some embodiments.

[0154] See also Fig.16 , the single-photon detector 100 includes a first material layer 10, an epitaxial layer 50, at least one first electrode 60 and at least one second electrode 80. The first material layer 10 has a first doping type. The epitaxial layer 50 is located on the surface of the first material layer 10, and at least one (e.g., one, or more) diode doping region 51 is provided in the epitaxial layer 50. The structure of the diode doping region 51 can refer to the description above. The first electrode 60 is located on a side of the epitaxial layer 50 away from the first material layer 10, and is connected to the diode doping region 51. The second electrode 80 is located on a side of the first material layer 10 away from the epitaxial layer 50, and is connected to the first material layer 10.

[0155] Exemplarily, the first electrode 60 is an anode, and the second electrode 80 is a cathode. At this time, the bias voltage is negative, and the absolute value of the bias voltage is the sum of the absolute value of the breakdown voltage and the overbias voltage.

[0156] Exemplarily, the first electrode 60 is a cathode, and the second electrode 80 is an anode. At this time, the bias voltage is positive, and the absolute value of the bias voltage is the sum of the absolute value of the breakdown voltage and the overbias voltage.

[0157] It is understood by those skilled in the art that, when working, a bias voltage Vop higher than the breakdown voltage is applied to the single-photon detector 100, and an avalanche region with a relatively high electric field strength is formed around the first doped portion 511 and the second doped portion 512. When a photon is incident (i.e., incident from the front), an incident path from the photon incident point to the first material layer 10 is formed, and the photon is absorbed by the main body 52 of the epitaxial layer 50 on the above-mentioned incident path and generates photogenerated carriers, which drift to the avalanche region located in the PN junction region under the action of the electric field, or diffuse into the depletion region under the action of the concentration difference, and then drift to the avalanche region under the action of the electric field, and collision ionization occurs in the avalanche region, generating an avalanche multiplication effect, and forming a large avalanche current to be collected by the second electrode 80.

[0158] According to the manufacturing method of the above-mentioned single-photon detector, the formed single-photon detector includes at least one SPAD. The epitaxial layer 50 includes a plurality of epitaxial sublayers arranged parallel to the first surface 101, and the material of the epitaxial sublayer can refer to the material of the epitaxial layer above; the first material layer 10 includes a plurality of first material sublayers arranged parallel to the first surface 101, and the material of the first material sublayer can refer to the material of the first material layer above. SPAD includes epitaxial sublayers and first material sublayers stacked in sequence, each epitaxial sublayer is provided with a diode doping region, and the first material sublayer has a first doping type. The material and structure of the diode doping region can refer to the description of the diode doping region above.

[0159] Some embodiments of the present disclosure also provide a detection device. The detection device is capable of emitting light and receiving light passing through an object to be detected, converting the received light signal into an electrical signal, and determining the internal image information and external image information of the object to be detected based on the electrical signal, thereby realizing the detection function. For example, the detection device can be any one of a security inspection device, a medical detection device, or an industrial non-destructive testing device, but is not limited thereto. The embodiments of the present application do not impose any special restrictions on the specific form of the above-mentioned detection device, and the structure of the detection device is illustrated below.

[0160] Fig.17 is a structural diagram of a detection device according to some embodiments.

[0161] See also Fig.17The detection device 1000 includes a single photon detector 100 , and the structure of the single photon detector 100 can refer to the above description. In some embodiments, the detection device 1000 may further include an emitter 200 and a processor 300 , and the processor 300 is electrically connected to the single photon detector 100 .

[0162] The emitter 200 is used to emit light. In some embodiments, the emitter 200 can be used to emit invisible light, such as X-rays or gamma rays, to ensure the penetration of light into the object to be detected, thereby improving the detection accuracy of the detection device 1000. In other embodiments, the emitter 200 can also be used to emit visible light. The present disclosure does not limit the type of light emitted by the emitter 200.

[0163] In some embodiments, there may be multiple emitters 200 , and the multiple emitters 200 are respectively disposed at different positions, so that light can be emitted from different positions to the object to be detected, thereby improving the reliability of the detection device 1000 .

[0164] In some embodiments, there may be multiple single-photon detectors 100 so as to receive light from different directions.

[0165] The processor 300 is electrically connected to the single-photon detector 100. It can be understood that the processor 300 is used to receive the electrical signal from the single-photon detector 100, and generate internal image information and external image information of the object to be detected according to the electrical signal from the single-photon detector 100. In some embodiments, the processor 300 can be a central processing unit (CPU) or a graphic processing unit (GPU).

[0166] In some embodiments, after the processor 300 generates the image information of the object to be detected, the image information can be transmitted to the outside of the detection device. In other embodiments, the detection device 1000 can also include a display device, which is used to display the image information generated by the processor. In this way, the user can intuitively obtain the internal image information and external image information of the object to be detected through the display device, thereby improving the convenience of using the detection device.

[0167] The beneficial effects that can be achieved by a detection device 1000 provided in some embodiments of the present disclosure are the same as the beneficial effects that can be achieved by the single-photon detector 100 provided by the above technical solution, and will not be repeated here.

[0168] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A method for manufacturing a single photon detector, characterized in that: include: providing a substrate; The base comprises a substrate and a first material layer formed on one side of the substrate; doping the first material layer; forming an epitaxial layer; The epitaxial layer is located on a surface of the first material layer away from the substrate; forming at least one diode doping region in the epitaxial layer; forming at least one first electrode; the first electrode is located on a side of the epitaxial layer away from the first material layer, and the first electrode is connected to the diode doping region; removing the substrate; At least one second electrode is formed; the second electrode is located on a side of the first material layer away from the epitaxial layer, and the second electrode is connected to the first material layer.

2. The method for manufacturing a single photon detector according to claim 1, characterized in that: The substrate further comprises: The second material layer is located between the substrate and the first material layer.

3. The method for manufacturing a single photon detector according to claim 2, characterized in that: The removing of the substrate comprises: removing a portion of the substrate by a chemical mechanical polishing process; The remaining portion of the substrate is removed through an etching process, with the second material layer serving as an etching stop layer.

4. The method for manufacturing a single photon detector according to claim 3, characterized in that: After removing the substrate, the second material layer is removed.

5. The method for manufacturing a single photon detector according to claim 1, characterized in that: In the forming of the epitaxial layer, the thickness of the epitaxial layer is greater than or equal to the thickness of the first material layer.

6. The method for manufacturing a single photon detector according to claim 1, characterized in that: The diode doping region includes a first doping portion and a second doping portion, wherein the first doping portion is in contact with the second doping portion; Before forming at least one first electrode, the method for manufacturing the single-photon detector further includes: A first electrode contact region is formed in the first doped portion; the doping concentration of the first electrode contact region is greater than the doping concentration of the first doped portion; In the forming of at least one first electrode, the at least one first electrode is in contact with the first electrode contact region.

7. The method for manufacturing a single photon detector according to claim 1, characterized in that: The forming of at least one first electrode comprises: forming an interlayer dielectric layer; the interlayer dielectric layer is located on a surface of the epitaxial layer away from the first material layer; forming a through hole on the interlayer dielectric layer; the through hole penetrates the interlayer dielectric layer and exposes the diode doping region; In the through hole, a first electrode is formed.

8. The method for manufacturing a single photon detector according to claim 1, characterized in that: Also includes: Before forming at least one second electrode, forming a trench isolation structure; The forming of the trench isolation structure comprises: forming a trench; the trench is located at the periphery of the diode doping region, and the dimension of the trench in the epitaxial layer along a first direction is less than or equal to the dimension of the epitaxial layer along the first direction; the first direction is the thickness direction of the first material layer; An isolation material is filled in the trench to form a trench isolation structure.

9. The method for manufacturing a single photon detector according to claim 8, characterized in that: The base also includes: a second material layer located between the substrate and the first material layer; The forming of the groove comprises: forming an opening on the second material layer, wherein the opening is located at a periphery of the diode doping region; doping the first material layer and the epitaxial layer through the opening to form a second contact region; A trench is formed in the second contact region; a dimension of the trench in a second direction is smaller than a dimension of the opening in the second direction, and the second direction is perpendicular to the first direction.

10. The method for manufacturing a single photon detector according to claim 1, characterized in that: The forming of the epitaxial layer further comprises: The epitaxial layer is doped, and the doping concentration of the epitaxial layer is lower than the doping concentration of the first material layer.

11. A single photon detector, characterized in that: The single-photon detector is manufactured by the manufacturing method of the single-photon detector according to any one of claims 1 to 10, comprising: A first material layer, the first material layer having a first doping type; An epitaxial layer, located on the surface of the first material layer; at least one diode doping region is arranged in the epitaxial layer; At least one first electrode, located on a side of the epitaxial layer away from the first material layer; the first electrode is connected to the diode doping region; At least one second electrode is located on a side of the first material layer away from the epitaxial layer; the second electrode is connected to the first material layer.

12. The single photon detector according to claim 11, characterized in that: A dimension of the trench isolation structure of the single-photon detector in the epitaxial layer along a first direction is smaller than or equal to a dimension of the epitaxial layer along the first direction; the first direction is a thickness direction of the first material layer.

13. A detection device, characterized in that: include: At least one single-photon detector, wherein the single-photon detector is the single-photon detector according to any one of claims 11-12.

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