WO2023092819A1 - Fin semiconductor device and preparation method therefor - Google Patents

Abstract

Provided in the present invention is a photosensitive sensor, comprising a top electrode, an isolation layer, a bottom electrode, several conductive structures, a support structure, and a multiplication structure array; each multiplication structure is inclined relative to the top electrode and is correspondingly and electrically connected to the conductive structure, such that several accelerating cavity structures are formed between the top electrode and the isolation layer; and an opening facing the top electrode is formed at the top of each accelerating cavity structure, and an emergent through hole is formed at the bottom of each accelerating cavity structure, the emergent through hole being opposite the bottom electrode, and photoelectrons being incident to the accelerating cavity structure, and being formed into secondary photoelectrons through acceleration and multiplication, so as to form amplified signals.

Description

Fin-type semiconductor device and manufacturing method thereof

cross reference

This application claims the priority of the Chinese patent applications with application numbers 202111410534.8, 202111410564.9 and 202111410349.9 filed on November 25, 2021. The content of the above application is incorporated herein by reference.

technical field

The invention relates to the field of integrated circuits, in particular to a photosensitive sensor and a preparation process thereof.

technical background

Conventional single-photon detectors use avalanche diodes, which have high operating voltage and poor integration; the breakdown voltage of avalanche diodes is sensitive to the process, resulting in high power consumption and poor uniformity. If it is used in the field of high-voltage work, the device area is large, and the avalanche diode is fabricated in the substrate, which cannot share the substrate area with the readout circuit, and cannot greatly increase the fill factor of the photosensitive area.

Therefore, it is necessary to provide a new type of photosensitive sensor and its preparation process, so as to improve the integration level and facilitate the improvement of the sensitivity to single photon detection.

Summary of the invention

The photosensitive sensor of the present invention includes: a top electrode, which is used to emit photoelectrons in response to light of a predetermined wavelength; an isolation layer, which is arranged opposite to the top electrode; a bottom electrode, which is arranged opposite to the top electrode and is electrically opposite; The conductive structure is arranged on the isolation layer; the support structure is formed into a cavity structure with the top electrode and the bottom electrode, and is electrically connected with the top electrode and the conductive structure; the multiplication structure array is arranged on The isolation layer includes several multiplication structures, each of the multiplication structures is inclined relative to the top electrode, and correspondingly electrically connected to the conductive structure, so as to form several acceleration cavity structures between the top electrode and the isolation layer , the top of each of the acceleration cavity structures is provided with an opening towards the top electrode, and the bottom is provided with an exit through hole, and the exit through hole is opposite to the bottom electrode; Accelerate and multiply to form secondary photoelectrons, and the photoelectrons and the secondary photoelectrons pass through the exit through hole to the bottom electrode

The present invention also provides a process for preparing a photosensitive sensor, which includes the following steps: S1: providing a substrate, forming a bottom electrode on the top surface of the substrate, exposing the top surface of the bottom electrode, and then forming a substrate on the bottom electrode Forming an isolation layer, the isolation layer has a number of initial through holes; S2: using conductive material to fill the number of initial through holes, forming a number of conductive structures, patterning the isolation layer, making the initial through holes and the conductive structure distributed at intervals, and arranged correspondingly to the bottom electrodes; S3: forming a first sacrificial layer, the first sacrificial layer covering the top surface of the isolation layer and filling the initial through holes, removing part of the first sacrificial layer to form several inclined structures, each of the inclined structures extends towards the same direction, and exposes the top surface of the isolation layer and at least part of the top surface of the conductive structure, and then deposits a dynode material to form a multiplication structure array, and the multiplication structure array includes several multiplication structures. structure, each of the multiplication structures is electrically connected to the corresponding conductive structure; S4: forming a second sacrificial layer, the second sacrificial layer fills the space between adjacent multiplication structures and covers the top surfaces of the plurality of multiplication structures, Forming an opposite groove structure on the second sacrificial layer, filling the groove structure with a support material to form a support structure; S5: depositing a top electrode material to form an initial top electrode, and the initial top electrode covers the support structure top surface and the top surface of the second sacrificial layer, and pattern the initial top electrode to form a release via hole, remove the first/second sacrificial layer through the release via hole, fill the release via with a sealing medium via holes to form the top electrode.

The beneficial effect of the present invention is that: an accelerating electric field is formed in the accelerating cavity structure, photoelectrons are accelerated and collided to form secondary photoelectrons, thereby amplifying the signal, improving the sensitivity of single photon detection, and improving the integration degree, the size is small, and no need to apply High voltage with controllable power consumption.

Description of drawings

Fig. 1 is the sectional view of a kind of photosensitive sensor of the embodiment of the present invention;

2 is a cross-sectional view of a photosensitive sensor according to Embodiment 1 of the present invention;

3 is a schematic diagram of the arrangement of positive V-shaped dynodes and inverted V-shaped dynodes in Embodiment 1 of the present invention;

4 to 11 are structural schematic diagrams of a preparation process of a photosensitive sensor according to Embodiment 1 of the present invention;

12 is a schematic structural view of a top electrode of a photosensitive sensor according to Embodiment 1 of the present invention;

Fig. 13 is a schematic structural diagram of another photosensitive sensor according to Embodiment 1 of the present invention;

14 to 18 are structural schematic diagrams of the preparation process of another photosensitive sensor according to Embodiment 1 of the present invention based on the structure shown in FIG. 5 ;

19 is a schematic structural diagram of a photosensitive sensor according to Embodiment 2 of the present invention;

Fig. 20 is a top view of several cavity structures in Embodiment 2 of the present invention;

Fig. 21 is a schematic structural diagram of the same sub-cavity array layer;

22 to 30 are structural schematic diagrams of the preparation process of the photosensitive sensor according to Embodiment 2 of the present invention;

31 is a schematic structural diagram of a photosensitive sensor according to Embodiment 3 of the present invention;

32 to 40 are structural schematic diagrams of a preparation process of a photosensitive sensor according to Embodiment 3 of the present invention;

FIG. 41 is a schematic structural diagram of another photosensitive sensor according to Embodiment 3 of the present invention.

Contents of the invention

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. the embodiment.

The invention provides a photosensitive sensor, which includes a top electrode, a bottom electrode, an isolation layer, several conductive structures, a supporting structure and several multiplying structures. Based on high integration and high detection sensitivity to single photons, it does not need to apply high voltage to realize the acceleration and cascade multiplication of photoelectrons.

As shown in Figure 1, the top electrode 11 responds to the light of predetermined wavelength to emit photoelectrons; The isolation layer 12 is arranged opposite to the top electrode 11; The bottom electrode 13 is arranged on the isolation layer 12, and is arranged opposite to the top electrode 11 and is electrically opposite; The structure 14 is arranged on the isolation layer 12; the support structure 15, the top electrode 11 and the isolation layer 12 form a cavity structure 16, and the support structure 15 is electrically connected to the top electrode 11; the multiplication structure array is arranged on the isolation layer 12, and includes several multiplying Structure 17, each multiplication structure 17 is inclined relative to the top electrode 11, and correspondingly electrically connected to the conductive structure 14, so as to form a number of acceleration cavity structures (not shown) between the top electrode 11 and the isolation layer 12, each of the acceleration cavity structures The top is provided with an opening facing the top electrode, and the bottom is provided with an exit through hole, and the exit through hole is opposite to the bottom electrode.

Each multiplication structure 17 is inclined to the top electrode 11 and the bottom electrode 13 and arranged perpendicularly to said bottom electrode. The top electrode is inclined to the bottom electrode. The top electrode is formed by connecting several top electrode units, and each of the top electrode units is inclined to the bottom electrode. The top electrode is prepared using a material having a photoelectric effect to emit photoelectrons in response to light of a predetermined wavelength. The material with photoelectric effect is any one of AgOCs and SbCs ₃ .

The acute angle between the extension line of the multiplication structure 17 towards the top electrode 11 and the top electrode 11 is 20°-65°, which is conducive to the transmission of photoelectrons to the multiplication structure 17, and accelerates through the acceleration cavity structure, and collides to form secondary photoelectrons, thereby amplifying signal, improving the sensitivity of single-photon detection. The material used for the dynode is GaP(Cs). Relative to the top electrode 11, several multiplication structures 17 are arranged obliquely towards the same direction to improve integration. The distance between adjacent multiplication structures 17 is smaller than the free path of electron transmission, so as to avoid energy loss of photoelectrons during transmission.

Referring to FIG. 1 , the photosensitive sensor (not marked) also includes a release through hole 18 , which communicates with the cavity structure 16 , and discharges by-products during the preparation process through the release through hole 18 . The photosensitive sensor can be used under non-vacuum conditions, and the release through hole 18 is arranged on the edge of the top electrode 11 to reduce the influence of photoelectrons generated on the top electrode 11.

The present invention also provides a preparation process of a photosensitive sensor, comprising:

S1: providing a substrate, forming a bottom electrode on the top surface of the substrate, exposing the top surface of the bottom electrode, and then forming an isolation layer on the bottom electrode, the isolation layer having a number of initial through holes;

S2: filling the plurality of initial through holes with a conductive material to form a plurality of conductive structures, patterning the isolation layer, so that the initial through holes are spaced apart from the conductive structures, and arranged corresponding to the bottom electrodes;

S3: forming a first sacrificial layer, the first sacrificial layer covering the top surface of the isolation layer and filling the initial through hole, removing part of the first sacrificial layer to form several inclined structures, each of which extends toward the same direction, And exposing the top surface of the isolation layer and at least part of the top surface of the conductive structure, and then depositing a dynode material to form a multiplication structure array, the multiplication structure array includes several multiplication structures, each of the multiplication structures is electrically connected to the corresponding the conductive structure;

S4: Form a second sacrificial layer, the second sacrificial layer fills the space between adjacent multiplication structures and covers the top surfaces of the plurality of multiplication structures, and forms opposite trench structures on the second sacrificial layer to fill the support material to the trench structure to form a support structure;

S5: Deposit top electrode material to form an initial top electrode, the initial top electrode covers the top surface of the support structure and the top surface of the second sacrificial layer, and pattern the initial top electrode to form a release via hole, through the The first/second sacrificial layer is removed for the release via hole, and the release via hole is filled with a sealing medium to form a top electrode.

Embodiment one

FIG. 2 is a cross-sectional view of a photosensitive sensor according to Embodiment 1 of the present invention. The difference between Fig. 2 and the photosensitive sensor shown in Fig. 1 is: Fig. 2 also includes a sealing medium layer 19, and the sealing medium layer 19 closes the release through hole (not marked), so that the cavity structure 16 forms a vacuum state, which can be applied to vacuum condition.

Referring to Fig. 2 and Fig. 3, each multiplication structure 17 comprises several positive V-shaped dynodes 171 and several inverted V-shaped dynodes 172, and both positive V-shaped dynodes 171 and inverted V-shaped dynodes 172 are phased by two inclined dynodes 170. Each of the inclined electrodes 170 is arranged obliquely relative to the top electrode 11 . Positive V-shaped dynodes 171 and inverted V-shaped dynodes 172 are arranged alternately with opposite electrical properties, and adjacent positive V-shaped dynodes 171 and inverted V-shaped dynodes 172 form an acceleration cavity structure 173 . Both sides of the positive V-shaped dynode 171 and the inverted V-shaped dynode 172 can be used, which is conducive to improving the multiplication effect of electrons, and makes the setting of the multiplication structure 17 more compact and highly integrated, reducing the size of the entire device. size of.

The positive V-shaped dynode 171 is a negative voltage dynode, and the inverted V-shaped dynode 172 is a positive voltage dynode. An accelerating electric field is formed in the accelerating cavity structure 173. After photoelectrons collide with the inclined dynode 170, they are multiplied to obtain secondary photoelectrons and achieve acceleration. Adjacent slanted dynodes 170 are electrically opposite so that no high voltage is required to achieve electron multiplication.

Referring to FIGS. 4 to 6 , the bottom electrode includes several anodes. The substrate 21 forms a plurality of anodes 22 with exposed top surfaces. The top surfaces of the anodes 22 and the top surface of the substrate 21 are deposited to cover the isolation layer 12 , and a plurality of conductive structures 14 filled with conductive materials are formed in the isolation layer 12 .

A metal interconnection structure 23 is formed between adjacent anodes 22 , and the metal interconnection structure 23 is electrically connected to the conductive structure 14 . Form a first conductive metal layer on the initial substrate, and pattern it to form a lower interconnection structure 33, deposit a dielectric material on the top of the lower interconnection structure 33 to form a bottom dielectric layer, and then form interconnection vias by photolithography etching, using The interconnection conductive structure 32 filling the interconnection via hole is formed after the interconnection metal material is deposited and subjected to CMP grinding.

A dielectric material is deposited to form a top dielectric layer, the top dielectric layer covers the top surface of the interconnection conductive structure 32 and the top surface of the bottom dielectric layer, and the anode 22 and the upper interconnection structure 31 are formed by depositing on the top dielectric layer. The upper layer interconnection structure 31 is in electrical contact with the lower layer interconnection structure 33 . The lower interconnection structure 33 , the interconnection conductive structure 32 and the upper interconnection structure 31 form a metal interconnection structure 23 , and the metal interconnection structure 23 is connected to a processing circuit. The initial substrate, the top dielectric layer and the bottom dielectric layer constitute a substrate 21 .

An isolation medium is deposited on the top surface of the anode 22 and the top surface of the substrate 21 , and the initial isolation layer is formed after CMP grinding, and then the initial isolation layer is patterned to form the isolation layer 12 with several initial through holes. The deposition and filling methods include any one of chemical vapor deposition process, electron beam evaporation process, atomic layer deposition process and sputtering process.

Referring to FIG. 5 , the initial through-holes are filled with conductive material to form a number of conductive structures 14 , and then the isolation layer 12 is patterned to form a number of outgoing through-holes 26 , and the several outgoing through-holes 26 are spaced apart from the several conductive structures 14 . The exit through hole 26 is opposite to the anode 22 , exposing the top surface of the anode 22 ; the conductive structure 14 is in electrical contact with the metal interconnection structure 23 .

Referring to Fig. 6, several inclined structures 27 are inclined toward the same direction, and the initial dynode layer 28 formed by depositing the dynode material covers the surface of the inclined structures 27, the top surface of the isolation layer 12 and the top surface of the conductive structure 14, and the sacrificial material also fills the Several outgoing through holes 26 are provided on the isolation layer 12 .

S3 includes: S31: forming a first sacrificial layer, the first sacrificial layer covering the top surface of the isolation layer and filling the initial through hole; S32: tilting the substrate, etching to form a cavity structure Cavity array, and then after the substrate is reset, the dynode material is deposited to form an initial dynode layer, and the initial dynode layer fills the cavity array, and then the substrate is tilted to remove part of the initial dynode The electrode layer obtains a multiplication structure array, and the multiplication structure array is arranged on the side wall of the cavity structure and is in electrical contact with the conductive structure.

In another embodiment, in S3, after setting the substrate at an inclination, before forming the first sacrificial layer, deposit an auxiliary sacrificial material to form several auxiliary inclined structures; after forming the first sacrificial layer, remove the second A sacrificial layer, the auxiliary sacrificial material is removed to form several inclined structures. Referring to FIG. 6 , the initial dynode layer 28 covers the sidewall and top surface of the inclined structure 27 , and also covers the top surface of the isolation layer 12 , so that the top surface of the conductive structure 14 is covered.

As shown in FIG. 7 , by cladding etching (Blanket etch), the top surface covering the conductive structure 14 and the initial dynode layer 28 covering the top surface of the isolation layer 12 are removed, exposing the top surface of the conductive structure 14 and the top surface of the isolation layer 12. top surface, and then etch the initial dynode layer 28 on the inclined structure 27 and its surface, the initial dynode layer 28 on the opposite side of the inclined structure 27 is reserved for tilting the dynode to form the multiplication structure 17, adjacent multiplication structures The space between 17 is opposite to the anode 22 through the exit through hole 26 . After removing the sacrificial layer, the multiplication structure is electrically connected to the conductive structure with the same orientation to improve integration. The inclined dynode is inclined to the top electrode and disposed on the isolation layer. The inclined dynodes corresponding to the isolation layers have the same or different heights.

Referring to FIG. 8, in S4, the sacrificial material is deposited to form a second sacrificial layer 41, and the second sacrificial layer 41 fills the space between adjacent multiplication structures and covers the top surfaces of the plurality of multiplication structures and the top surface of the isolation layer 12. . Referring to FIG. 9 , an opposite trench structure 42 is formed on the second sacrificial layer 41 .

Referring to FIG. 1, FIG. 9 and FIG. 10, in S4, a support material is deposited to form an initial support structure, the initial support structure fills the trench structure 42, and covers the second sacrificial layer 41, part of the initial support structure is removed, and The top surface of the second sacrificial layer 41 is exposed to form a support structure 15 , and the support structure 15 includes a first support structure 44 and a second support structure 45 .

Referring to FIG. 1 , FIG. 10 and FIG. 11 , in S5 , the top electrode material is deposited to form the initial top electrode 43 , and the initial top electrode 43 covers the top surface of the second sacrificial layer 41 , the first support structure 44 and the second support structure 45 . The initial top electrode 43 is patterned to form the release via hole 18 , and the second sacrificial layer 41 is removed through the release via hole 18 to form the top electrode 11 . Referring to FIG. 2 , after S5 , it also includes: using the sealing medium 19 to seal the release through hole 18 , and removing the sealing medium on the top surface of the initial top electrode 43 to form the top electrode 11 .

In the high-vacuum film forming equipment, a dielectric deposition process is used to fill the release through hole 18 with a sealing medium 19 to block the release through hole 18; then the sealing medium on the surface of the initial top electrode 43 is removed by blanket etching. Referring to FIG. 12 , the top electrode 11 includes different top electrode units 51 , and each top electrode unit 51 is disposed obliquely to the bottom electrode 13 . Referring to FIG. 13 , several multiplication structures 17 are arranged perpendicular to the bottom electrode 13 , and the top electrode 11 has a tapered structure. The top electrode units 51 are connected in series to realize electrical contact. Photolithography is performed using a grayscale mask to form a tapered structure that gradually thickens from the edge to the middle, and a cathode material is deposited on the top surface of the tapered structure to form an initial top electrode.

Referring to Figures 14 to 18, another embodiment, S3 includes:

S301: forming a first sacrificial layer 201 on a top surface of part of the isolation layer 12;

S302: Obliquely etch the first sacrificial layer 201 to expose the conductive structure 14, so as to form a first inclined window pattern 202 that is inclined and faces the same direction, as shown in FIG. 14 ;

S303: reverse obliquely etch the first sacrificial layer 201 to expose the conductive structure 14, so as to form a second inclined window pattern 203 that is inclined and oriented opposite to the direction of the first inclined window pattern 202, as shown in FIG. 15 ;

S304: Deposit the dynode material on the surface of the first sacrificial layer 201 and the conductive structure 14, remove the dynode material on the upper surface of the first sacrificial layer 201 through an etching process to expose the first sacrificial layer 201, and make the first inclined window pattern 202 and an initial dynode 204 is formed in the second inclined window pattern 203, as shown in FIG. 16;

S305: removing part of the dynode material to form a dynode structure 17, and electrically connecting the dynode structure 17 to the conductive structure, as shown in FIG. 17 ;

S306: remove the first sacrificial layer 201 and part of the isolation layer, so that the adjacent multiplication structure 17 forms a positive V-shaped dynode 171 and an inverted V-shaped dynode 172, and encloses an acceleration cavity structure 173, as shown in FIG. 18 Show.

Embodiment two

Referring to Fig. 19, the upper layer cavity array 13 and the lower layer cavity array 14 form an accelerating cavity array, the accelerating cavity array is arranged between the top electrode 11 and the bottom electrode 12, and the top surface opening of the accelerating cavity array faces the top electrode 11 , the opening of the bottom surface faces the bottom electrode 12 , forming a number of acceleration cavities 17 for the passage of the photoelectrons and secondary electrons, and allowing the secondary photoelectrons to reach the bottom electrode 12 . Referring to FIG. 20 , taking the first acceleration chamber structure 131 as an example, along the direction in which the top electrode 11 is arranged, the cross-section of each acceleration chamber structure is an equilateral hexagon.

The dynodes 15 face each other in pairs and are arranged in each acceleration cavity 17. The photoelectrons are accelerated and multiplied by the dynodes 15 to form the secondary photoelectrons, which improves the integration and is beneficial to improve the sensitivity of weak light detection.

Referring to FIG. 19 , several accelerating chambers 17 are arranged in a direction oblique to the top electrode 11 .

The multiplication structure includes a pair of dynodes, and the pair of dynodes is arranged opposite to each acceleration cavity structure, so that an accelerating electric field is formed between adjacent dynodes in the same cavity structure.

Along the direction inclined to the top electrode, the multiplication structure array includes several sub-cavity array layers, each of the sub-cavity array layers is inclined to the top electrode, and the accelerating cavity structures of adjacent sub-cavity array layers are opposite to each other. In addition, the cavity structures of the same sub-cavity array layer have top openings facing the top electrode and bottom openings facing the bottom electrode.

Among the 8 cavity structures shown in Figure 19, 4 accelerating cavity structures are arranged to form the upper cavity array layer 13, and the upper cavity array layer 13 is used as a sub-cavity array layer, and the other 4 accelerating cavity structures are arranged to form The lower cavity array layer 14, the lower cavity array layer 14 serves as another sub-cavity array layer. The upper cavity array layer 13 and the lower cavity array layer 14 are disposed between the top electrode 11 and the bottom electrode 12 . Each accelerating cavity structure of the upper cavity array layer 13 and each accelerating cavity structure of the lower cavity array layer 14 are provided in a one-to-one correspondence. The number of accelerating cavity structures can be flexibly adjusted according to requirements.

In the adjacent accelerating cavity structures of different sub-cavity array layers, the exit through hole of the accelerating cavity structure close to the top electrode corresponds to the opening of the accelerating cavity structure close to the bottom electrode, so as to allow the photoelectron and secondary Photoelectrons pass through. Referring to FIG. 19 , the exit holes of adjacent first accelerating cavity structures 131 are connected to the openings of the second accelerating cavity structures 141 , so that the first accelerating cavity structures 131 and the second accelerating cavity structures 141 communicate with each other.

Referring to FIG. 19 and FIG. 21 , the photosensitive sensor further includes an interlayer isolation layer. There is an interlayer isolation layer 16 between the upper cavity array layer 13 and the lower cavity array layer 14, and the interlayer isolation layer 16 includes several interlayer conductive structures 161, and several interlayer conductive structures 161 located opposite along the horizontal direction. An interlayer via structure (not shown) for photoelectrons to pass through.

The interlayer conductive structure 161 is in electrical contact with several multiplication structures of at least one layer adjacent to the sub-cavity array layers. Referring to FIG. 21 , the interlayer conductive structure 161 electrically contacts the first dynode 151 and the second dynode 152 , and the first dynode 151 and the second dynode 152 belong to the same sub-cavity array layer. The bottom of each cavity structure is provided with an accelerating film, the accelerating film has a channel hole, the channel hole is used as the bottom opening of the cavity structure, and strengthens the acceleration of the secondary photoelectrons emitted by the cavity structure . The accelerating film is composed of at least one of reduced graphene and graphene oxide layers.

Referring to FIG. 21 , except for several interlayer conductive structures 161 , other parts of the interlayer isolation layer 16 and the accelerating electrodes 162 constitute the accelerating film. The accelerating electrode 162 has a porous structure to allow photoelectrons and secondary photoelectrons to pass through for acceleration. Other parts of the interlayer isolation layer 16 except for some interlayer conductive structures 161 are composed of graphene oxide, and the accelerating electrode 162 is composed of reduced graphene. The accelerating film is isolated from the dynodes in the adjacent accelerating cavity structure so as not to be electrically connected. In adjacent accelerating cavity structures, the dynodes include a first dynode 151 and a second dynode 152 .

The motion channel formed by the adjacent accelerating cavity structures of different sub-cavity array layers is V-shaped. Please refer to FIG. 19, the adjacent accelerating cavity structures of different sub-cavity array layers, taking the first accelerating cavity structure 131 and the second accelerating cavity structure 141 as an example, the first accelerating cavity structure 131 and the second accelerating cavity structure 141 form The structure is V-shaped. The dynode pairs of the same sub-cavity array layer are arranged facing the same direction. The bottom electrode includes a number of anodes isolated from each other, and the anodes are arranged in one-to-one correspondence with the acceleration chamber structure closest to the bottom electrode.

Referring to Fig. 22 and Fig. 23 for the photosensitive sensor according to the second embodiment of the present invention, the bottom electrode includes several anodes. The substrate 21 is formed with a number of anodes 22 with exposed top surfaces, and the top surfaces of the anodes 22 and the top surface of the substrate 21 are deposited and covered with an isolation layer 24, and the isolation layer 24 is formed with a number of conductive structures 25 filled with conductive materials.

A metal interconnection structure 23 is formed between adjacent anodes 22 for external processing circuit, and the metal interconnection structure 23 is electrically connected with the conductive structure 25 . The interconnection conductive structure 32 and the underlying interconnection structure 33 constitute the metal interconnection structure 23 . Specifically, a first conductive metal layer is formed on the initial substrate, and the underlying interconnection structure 33 is patterned, a sacrificial material is deposited on the top of the underlying interconnection structure 33 to form a first sacrificial layer, and then the interconnection is formed by photolithography. The through holes are deposited by interconnecting metal materials and smoothed by CMP to form the interconnected conductive structures 32 filling the interconnected through holes.

Depositing a sacrificial material to form a second sacrificial layer, the second sacrificial layer covering the top surface of the interconnection conductive structure 32 and the first sacrificial layer, forming the anode 22 and the upper interconnection structure 31 on the second sacrificial layer, The upper interconnection structure 31 is electrically contacted with the lower interconnection structure 33 through the interconnection conductive structure 32 . The initial substrate, the second sacrificial layer and the first sacrificial layer constitute a substrate 21 .

Specifically, the top surface of the anode 22 is exposed, and after depositing an initial isolation layer (not indicated) on the top surface of the anode 22 and the top surface of the substrate 21, the initial isolation layer (not indicated) is patterned to form several initial through holes .

Referring to FIG. 23 , the initial through holes are filled with conductive material to form a number of conductive structures, and then the initial isolation layer is patterned, and several outgoing through holes are formed in the initial isolation layer by etching, and several of the The exit through holes are distributed at intervals with several conductive structures. In the isolation layer 24, the conductive structure 25 and the exit through hole 26 are distributed at intervals, and the exit through hole 26 is opposite to the anode 22, exposing at least part of the top surface of the anode 22; the conductive structure 25 is in electrical contact with the metal interconnection structure 23.

In the second embodiment, S3 includes: tilting the substrate, etching to form a cavity array including several cavity structures, and then resetting the substrate, depositing a dynode material to form an initial dynode layer, the initial The dynode layer fills the cavity array, and then the substrate is tilted to remove part of the initial dynode layer to obtain a multiplication structure disposed on the sidewall of the cavity structure and in electrical contact with the conductive structure.

Referring to FIGS. 23 and 24 , the sacrificial material covering the top surface of the isolation layer 24 and filling the exit holes 26 is removed by etching, and a part of the sacrificial material covering the conductive structure 25 is also removed to form several inclined structures 61. The structures 61 are in contact with the conductive structures 25 , are parallel to each other and are inclined to the substrate 21 , adjacent inclined structures 61 form a cavity with a top opening, and the top opening of each cavity is opposite to the anode 22 . Specifically, the sacrificial material is an insulating material.

The dynode material is deposited to form an initial dynode layer (not shown). The initial dynode layer covers the isolation layer 24 and several conductive structures 25 , fills the emission via hole 26 and covers each inclined structure 61 . Referring to FIG. 25, after removing part of the initial dynode layer by anisotropic etching, several dynodes 71 as shown in FIG. The dynode 71 is electrically connected to the conductive structure 25 .

The cavity array includes several sub-cavity array layers, and after the formed sub-cavity array layers are formed in S3, the following steps are performed:

S331: Fill the inside of the formed sub-cavity array layer with a sacrificial material, exposing the top surface of the formed sub-cavity array layer;

S332: Use an interlayer material to form an interlayer isolation layer, the interlayer isolation layer covers the formed sub-cavity array layer, and includes several interlayer conductive structures and several interlayer via structures, each of the interlayer The through-hole structure is arranged relative to the corresponding acceleration cavity structure of the formed sub-cavity array layer, and at least part of the surface of the interlayer conductive structure is exposed; wherein, S3, S331 and S332 are repeatedly executed until several layers of sub-cavities are formed Array layer, the interlayer isolation layer is provided between adjacent sub-cavity array layers, and at least one multiplication structure of the sub-cavity array layer is in electrical contact with the interlayer conductive structure.

For the formation process of the interlayer isolation layer 16, please refer to the formation process of the conductive structure 25 and the exit through hole 26. The difference is that, referring to FIG. 21 and FIG. 26, each interlayer isolation layer is 16 to form an interlayer conductive structure 161, and then spin-coat the dispersion on the top surface of each interlayer isolation layer 16 and between the top surfaces of adjacent interlayer isolation layers 16, so as to realize the channel between adjacent cavity arrays. of the seal. The dispersion liquid is a dispersion liquid containing graphene oxide and an organic solvent. After S332, the dispersion liquid is spin-coated on openings of the acceleration chamber structure, and the graphene oxide layer covers at least one of the openings and is in contact with the interlayer conductive structure.

Referring to FIG. 27 , a second layer cavity array 92 is deposited on top of the first layer cavity array 91 . The inclined structures of the cavity array 92 on the second layer are parallel to each other, and form the same angle with the inclined structures connected along the vertical direction. For the formation method of the several dynodes provided in the cavity array 92 on the second layer, please refer to the above, and details will not be repeated here.

27 to 30, the sacrificial material is filled to form the second sacrificial layer 101, and after forming the opposite trench structures on the second sacrificial layer 101, that is, the first trench structure 102 and the second trench structure 103, a supporting material is used The two trench structures are filled to form a first support structure 111 and a second support structure 112 . Deposit top electrode material, the top electrode material covers the top surface of the first support structure 111 and the second support structure 112, and the top surface of the second sacrificial layer 101 to form the initial top electrode 113, patterning the initial top electrode 113 to form a release through hole 114 .

After the sacrificial material is removed through the release via hole 114 , a sealing medium is used to seal the release via hole, and the sealing medium on the top surface of the initial top electrode 113 is removed to form a top electrode. And the release through hole 114 is reserved to communicate with the cavity structure. Removing a portion of the graphene oxide layer, so that the structures of the relative acceleration chambers along the longitudinal direction are communicated, and then using a sealing medium to seal the release through hole, and removing the sealing medium on the top surface of the initial top electrode.

In S5, removing part of the graphene oxide layer includes forming a channel hole in each graphene oxide layer by photolithography, so as to communicate with the opposing acceleration cavity structures along the longitudinal direction. Then reduce the remaining graphene oxide layer to obtain an accelerating electrode.

Embodiment three

In the photosensitive sensor shown in Figure 31, several isolation layers 14 are arranged in the cavity structure, and the cavity structure is separated to form several sub-cavity structures 18, and each isolation layer 14 is correspondingly provided with some conductive structures (not marked). ) and a plurality of multiplication structure arrays, each of the conductive structures is electrically connected to the support structure; between adjacent isolation layers, the exit through hole of the multiplication structure array near the top electrode is used as a hole near the bottom electrode For the opening of another multiplication structure array, referring to FIG. 31 , the through hole 161 at the bottom of one accelerating cavity structure is opposite to the through hole 162 at the bottom of the other accelerating cavity to improve integration and reduce the movement distance and energy loss of photoelectrons. Each of the multiplication structures is inclined towards the same direction to improve integration. The top electrode 11 and the bottom electrode 12 are arranged along the same direction, and several multiplication structures 15 are inclined to the top electrode 11 and the bottom electrode 12 .

A plurality of multiplication structures 15 are arranged obliquely on each isolation layer 14 relative to the top electrode 11 and are electrically connected to the conductive structures (not shown) in one-to-one correspondence, separating each sub-cavity structure 18 to form an acceleration whose top opens toward the top electrode 11. The cavity structure (not shown) is used to receive incident photoelectrons and accelerate and multiply the incident photoelectrons to form secondary photoelectrons. The bottom of each accelerating cavity structure is opened to allow the secondary photoelectrons to pass through holes 16 , and also includes two opposite multiplication structures 15 . An accelerating electric field is formed between adjacent multiplication structures 15 , and photoelectrons are accelerated between adjacent multiplication structures 15 by using the accelerating electric field and collide to form more photoelectrons to form amplified photoelectron signals. The number of accelerating cavity structures in each sub-cavity structure 18 is greater than one. The distance between adjacent multiplication structures 15 is smaller than the free path of photoelectron transmission, so as to avoid the energy loss of photoelectrons in the transmission process to the greatest extent.

In the adjacent accelerating cavity structures of different isolation layers 14, the through hole of one accelerating cavity structure close to the top electrode 11 is used as the photoelectron entrance of another accelerating cavity structure close to the bottom electrode 12, so that the secondary photoelectrons can be continuously accelerated and accelerated. Cascaded multiplication and receiving by the bottom electrode, the integration degree is improved and the sensitivity to single photon or weak light detection is improved.

The photosensitive sensor also includes an accelerating electrode. The accelerating electrode attracts and accelerates electrons, and the electrons reach the multiplication structure 15 through the accelerating electrode. Referring to FIG. 31 , the accelerating electrode 17 is arranged close to the top electrode 11 to accelerate the photoelectrons and make at least part of the photoelectrons reach the accelerating cavity structure surrounded by adjacent multiplication structures 15 and having a through hole 16 at the bottom. The accelerating electrode 17 is arranged on the bottom surface of the top electrode 11, and is formed between the top surfaces of the accelerating cavity structures of the top cavity structure, and has several accelerating through holes.

The accelerating electrode is arranged between the bottom surface of the top electrode and the top surface of the top accelerating cavity structure, and is provided with a number of accelerating through holes, at least a part of the accelerating through holes correspond to each of the top accelerating cavity structures, and the optoelectronic Through the acceleration through hole to the top acceleration cavity structure, the degree of integration is improved and the movement distance of photoelectrons is reduced. In the corresponding acceleration cavity structures of the adjacent isolation layers, the multiplication structures located on the same side are coaxial, which further improves the degree of integration. Moreover, along the vertical direction, the photoelectrons sequentially pass through each of the sub-cavity structures, further accelerating and cascading multiplication, without occupying more projected area of the substrate, and reducing the processing cost. The adjacent accelerating cavity structures of the isolation layers of different layers have the same structure, which can share the projected area of the substrate and improve the integration degree.

A bottom electrode is formed on the top surface of the substrate to expose the top surface of the bottom electrode, and then a first isolation layer with several initial through holes is formed on the bottom electrode. 32 to 34, the bottom electrode includes a number of anodes, the substrate 21 is formed with a number of anodes 22 exposed on the top surface, the top surface of the anode 22 and the top surface of the substrate 21 are deposited and covered with a first isolation layer 24, the first A number of conductive structures 25 filled with conductive material are formed in an isolation layer 24 .

A metal interconnection structure 23 is formed between adjacent anodes 22 , and the metal interconnection structure 23 is electrically connected to the conductive structure 25 . A first conductive metal layer is formed on the initial substrate, the first conductive metal layer is patterned to form a lower interconnection structure 33, a dielectric material is deposited on the top of the lower interconnection structure 33 to form a bottom dielectric layer, and then formed by photolithography The interconnection vias are deposited using interconnection metal material and smoothed by CMP to form the interconnection conductive structures 32 filling the interconnection vias.

After depositing a dielectric material to form a top dielectric layer covering the top surface of the interconnection conductive structure 32 and the top surface of the bottom dielectric layer, deposit and form the anode 22 and the upper interconnection structure 31 on the top dielectric layer, so that the upper interconnection structure 31 is in electrical contact with an underlying interconnection structure 33 through an interconnection conductive structure 32 . The lower interconnection structure 33 , the interconnection conductive structure 32 and the upper interconnection structure 31 constitute the metal interconnection structure 23 , which is externally connected to the processing circuit. The initial substrate, the top dielectric layer and the bottom dielectric layer constitute a substrate 21 . The top surface of the anode 22 is exposed. After depositing an initial isolation layer (not marked) on the top surface of the anode 22 and the top surface of the substrate 21, the isolation layer is patterned to form a first through hole (not indicated) with several initial Isolation layer 24.

Referring to FIG. 34 , in this embodiment, conductive materials are used to fill the initial via holes to form several conductive structures, and the first isolation layer is patterned so that the plurality of via holes formed by the first isolation layer are connected to the plurality of conductive structures. Structural interval distribution. In the first isolation layer 24 , conductive structures 25 and outgoing through holes 26 are distributed at intervals, and the outgoing through holes 26 are opposite to the anode 22 , exposing the top surface of the anode 22 ; the conductive structure 25 is in electrical contact with the metal interconnection structure 23 .

Referring to FIG. 32 , after depositing a sacrificial material to form a first sacrificial layer covering the top surface of the first isolation layer and filling the through holes, part of the sacrificial material is removed to form several inclined structures extending in the same direction, and the The top surface of the first isolation layer and at least part of the top surface of the conductive structure are exposed, and then the dynode material is deposited to form several dynode structures electrically connected to the conductive structure. Several inclined structures 27 are inclined towards the same direction, and the initial dynode layer formed by depositing the dynode material covers the surface of the inclined structures 27, the top surface of the first isolation layer 24 and the top surface of the conductive structure 25, and the sacrificial material also fills the first dynode layer. Several outgoing through holes 26 are provided on the isolation layer 24 .

In this embodiment, after the first sacrificial layer is formed, the substrate is tilted, and then part of the first sacrificial layer is etched away to form several tilted structures, and the top surface of the isolation layer and at least part of the conductive structure The top surface is exposed.

In another embodiment, after the substrate is tilted, first use auxiliary sacrificial material deposition to form several auxiliary tilting structures, then use sacrificial material deposition to form a first sacrificial layer covering the top surface of the auxiliary tilting structures, and then etch to remove After the sacrificial material on the same side of the plurality of auxiliary inclined structures is removed, the auxiliary sacrificial material is formed to form several inclined structures, and the top surface of the isolation layer and at least part of the top surface of the conductive structure are exposed.

Referring to FIG. 32 , the initial dynode layer 28 covers the sidewall and top surface of the inclined structure 27 , and also covers the top surface of the first isolation layer 24 , so that the top surface of the conductive structure 25 is covered. The initial dynode layer 28 covering the top surface of the conductive structure 25 and the top surface of the first isolation layer 24 is removed by cladding etching (Blanket etch), so that the top surface of the conductive structure 25 and the top surface of the first isolation layer 24 are exposed , and then remove the initial dynode layer on the top surface of the inclined structure 27, and then keep the opposite side covered with the initial dynode layer as an inclined dynode, and the inclined structure 27 provides a supporting function.

Then, the sacrificial layer is removed, and the inclined dynode is electrically connected to the conductive structure with the same orientation, so as to improve integration. Referring to FIG. 35 , in this implementation, the sacrificial material is deposited to form a second sacrificial layer that fills the space between adjacent multiplication structures and covers the top surfaces of the several multiplication structures. The second sacrificial layer 52 fills the space between adjacent dynodes 51 and covers the top surface of the first isolation layer 24 .

Referring to FIG. 36 , S2 and S3 are repeated until several isolation layers are formed, and several multiplication structures 15 are formed in each isolation layer, and the conductive structures adjacent to the isolation layers are arranged oppositely, and the sacrificial material is filled phase The space between adjacent multiplication structures 15 forms a complete sacrificial layer 61 .

36 to 38, in S5, after forming opposite trench structures on the complete sacrificial layer 61, that is, the first trench structure 711 and the second trench structure 712, the support material is used to fill the two trench structures to form the second trench structure. A support structure 131 and a second support structure 132 .

Referring to Figure 36, Figure 39 and Figure 40, in S6, the top electrode material is used to deposit and form the top surface of the support structure, that is, the top surface of the first support structure 131 and the second support structure 132, and the top surface of the complete sacrificial layer 61 Initial top electrode 91 . The initial top electrode 91 is patterned to form a release via 101 . After the sacrificial material is removed through the release via hole, a sealing medium is used to seal the release via hole and the sealing medium on the top surface of the initial top electrode 91 is removed to form a top electrode. And retain the release through hole to communicate with the cavity structure.

The photosensitive sensor also includes several horizontal dynodes, and at least one of the bottom of the acceleration cavity structure is adjacent to the through hole opened and two of the horizontal dynodes are oppositely arranged to enhance the acceleration of secondary photoelectrons. The horizontal dynode is disposed on at least part of the exposed surface of the isolation layer.

FIG. 41 is a schematic structural diagram of another photosensitive sensor according to Embodiment 3 of the present invention. Several multiplication structures 15 are arranged perpendicular to the bottom electrode 12 , and the top electrode 111 is in a tapered structure. A plurality of multiplication structures 15 are perpendicular to each layer of the isolation layer, and are electrically connected to the conductive structures (not shown) one by one, and each sub-cavity structure is separated to form an acceleration chamber structure (not shown) whose top is opened toward the top electrode 111. marked) to receive incident photoelectrons and accelerate and multiply the incident photoelectrons to form secondary photoelectrons.

The above are only preferred embodiments of the present invention, and the embodiments are not intended to limit the scope of patent protection of the present invention, so all equivalent structural changes made by using the description and drawings of the present invention should be included in the same reason Within the protection scope of the appended claims of the present invention.

Claims (36)

1. A photosensitive sensor is characterized in that, comprising:

   a top electrode for emitting photoelectrons in response to light of a predetermined wavelength;

   an isolation layer disposed opposite to the top electrode;

   a bottom electrode disposed opposite to the top electrode and electrically opposite;

   a plurality of conductive structures disposed on the isolation layer;

   a supporting structure, forming a cavity structure with the top electrode and the bottom electrode, and electrically connected with the top electrode and the conductive structure;

   The multiplication structure array is arranged on the isolation layer, including a plurality of multiplication structures, each of the multiplication structures is inclined relative to the top electrode, and correspondingly electrically connected to the conductive structure, so as to be between the top electrode and the isolation layer A number of acceleration chamber structures are formed between them, the top of each acceleration chamber structure is provided with an opening facing the top electrode, and the bottom is provided with an exit hole, and the exit through hole is opposite to the bottom electrode;

   Wherein, photoelectrons are incident to the accelerating cavity structure, and are accelerated and multiplied to form secondary photoelectrons, and the photoelectrons and the secondary photoelectrons pass through the exit through hole to the bottom electrode.
2. The photosensitive sensor according to claim 1, wherein an acute angle at which an extension line of the multiplication structure toward the top electrode intersects the top electrode is 20°-65°.
3. The photosensitive sensor according to claim 1, wherein the distance between adjacent multiplication structures is smaller than the free path of electron transmission.
4. The photosensitive sensor according to claim 1, characterized in that, relative to the top electrode, each of the multiplication structures is inclined in the same direction.
5. The photosensitive sensor according to claim 1, wherein each of the multiplication structures includes a plurality of inclined dynodes, the electrical properties of adjacent inclined dynodes are opposite, and each of the inclined dynodes is arranged obliquely relative to the top electrode .
6. The photosensitive sensor according to claim 1, wherein each of the multiplication structures comprises several positive V-type dynodes and several inverted V-type dynodes, and the positive V-type dynodes and the inverted V-type dynodes alternate Each of the positive V-shaped dynodes and each of the inverted V-shaped dynodes are formed by connecting two inclined dynodes, and each of the inclined dynodes is arranged obliquely relative to the top electrode.
7. The photosensitive sensor according to claim 1, further comprising a release through hole and a sealing medium layer, the release through hole is opened on the edge of the top surface of the cavity structure, and the sealing medium layer seals the release through hole hole.
8. The photosensitive sensor according to claim 1, wherein the plurality of multiplication structures are inclined to the bottom electrode, or the plurality of multiplication structures are perpendicular to the bottom electrode, and the top electrode is inclined to the bottom electrode electrode.
9. The photosensitive sensor according to claim 1, wherein the top electrode is in a cone-shaped structure.
10. The photosensitive sensor according to claim 1, further comprising a metal interconnection structure, the metal interconnection structure is in electrical contact with the bottom electrode to electrically connect a processing circuit.
11. The photosensitive sensor according to claim 1, characterized in that, the cross-section of each of the accelerating cavity structures along the direction in which the top electrodes are arranged is an equilateral hexagon.
12. The photosensitive sensor according to claim 11, characterized in that an accelerating thin film is arranged at the bottom of at least one of the accelerating cavity structures to accelerate the secondary photoelectrons.
13. The photosensitive sensor according to claim 12, wherein the accelerating film comprises one or a combination of reduced graphene and graphene oxide.
14. The photosensitive sensor according to claim 12, wherein the accelerating film has at least one channel hole as the exit through hole.
15. The photosensitive sensor according to claim 11, wherein the multiplication structure array comprises several sub-cavity array layers, each of the sub-cavity array layers is inclined to the top electrode, and the adjacent sub-cavity array layers are The acceleration chamber structures are opposite and communicated with each other.
16. The photosensitive sensor according to claim 15, further comprising: several interlayer isolation layers, several interlayer conductive structures, and several interlayer through hole structures, the adjacent sub-cavity array layers are provided with the The interlayer isolation layer, and at least one multiplication structure of the sub-cavity array layer electrically contacts the interlayer conductive structure, and the accelerating cavity structure of any one of the sub-cavity array layers is opposite to the interlayer via structure , the photoelectrons pass through the interlayer via structure.
17. The photosensitive sensor according to claim 11, characterized in that, the multiplication structure includes a pair of dynodes, and the pair of dynodes is arranged opposite to the inner wall of each acceleration cavity structure.
18. The photosensitive sensor according to claim 17, characterized in that, between different said sub-cavity array layers, the motion channels formed by adjacent accelerating cavity structures are V-shaped.
19. The photosensitive sensor according to claim 1, wherein a plurality of isolation layers are arranged in the cavity structure, and the cavity structure is separated to form a plurality of sub-cavity structures, and each isolation layer is correspondingly provided with a plurality of sub-cavity structures. a conductive structure and a plurality of multiplication structure arrays, each of the conductive structures is electrically connected to the support structure;

    Wherein, between the adjacent isolation layers, the exit through hole of the multiplication structure array close to the top electrode serves as an opening of another multiplication structure array close to the bottom electrode.
20. The photosensitive sensor according to claim 19, wherein the top accelerating cavity structure is an accelerating cavity structure corresponding to the multiplication structure array closest to the top electrode, further comprising: an accelerating electrode, arranged on the top accelerating cavity structure, to accelerate the photoelectrons, and make at least part of the photoelectrons reach the top accelerating cavity structure.
21. The photosensitive sensor according to claim 19, wherein the accelerating electrode is arranged between the bottom surface of the top electrode and the top surface of the top accelerating cavity structure, and is provided with a number of accelerating through holes, at least a part of which is The acceleration through holes correspond to the top accelerating cavity structures, and the photoelectrons pass through the accelerating through holes to the top accelerating cavity structures.
22. The photosensitive sensor according to claim 19, wherein each of said multiplication structures is inclined towards the same direction.
23. The photosensitive sensor according to claim 21, characterized in that the acceleration cavity structures corresponding to the same side of different isolation layers are coaxial.
24. The photosensitive sensor according to claim 19, wherein the multiplication structure includes inclined dynodes, each inclined dynode is inclined to the top electrode, is arranged on each of the isolation layers, and is electrically connected to the conductive structure connected and have the same inclination angle; the inclination dynodes corresponding to the isolation layers in the same layer have the same or different heights.
25. The photosensitive sensor according to claim 19, further comprising a plurality of horizontal dynodes, at least one of the sub-cavity structures corresponding to each exit through-hole adjacent to two of the horizontal dynodes, to accelerate the secondary photoelectrons.
26. A method for preparing a photosensitive sensor, characterized in that it comprises:

    S1: providing a substrate, forming a bottom electrode on the top surface of the substrate, exposing the top surface of the bottom electrode, and then forming an isolation layer on the bottom electrode, the isolation layer having a number of initial through holes;

    S2: Filling the plurality of initial through holes with a conductive material to form a plurality of conductive structures, patterning the isolation layer, so that the initial through holes are spaced apart from the conductive structures, and arranged corresponding to the bottom electrodes;

    S3: forming a first sacrificial layer, the first sacrificial layer covering the top surface of the isolation layer and filling the initial through hole, removing part of the first sacrificial layer to form several inclined structures, each of which extends toward the same direction, And exposing the top surface of the isolation layer and at least part of the top surface of the conductive structure, and then depositing a dynode material to form a multiplication structure array, the multiplication structure array includes several multiplication structures, each of the multiplication structures is electrically connected to the corresponding the conductive structure;

    S4: Form a second sacrificial layer, the second sacrificial layer fills the space between adjacent multiplication structures and covers the top surfaces of the plurality of multiplication structures, and forms opposite trench structures on the second sacrificial layer to fill the support material to the trench structure to form a support structure;

    S5: Deposit top electrode material to form an initial top electrode, the initial top electrode covers the top surface of the support structure and the top surface of the second sacrificial layer, and pattern the initial top electrode to form a release via hole, through the The first/second sacrificial layer is removed for the release via hole, and the release via hole is filled with a sealing medium to form a top electrode.
27. The method according to claim 26, wherein S3 comprises:

    S31: forming a first sacrificial layer, the first sacrificial layer covering the top surface of the isolation layer and filling the initial through hole;

    S32: Tilt the substrate, etch to form a cavity array including several cavity structures, then reset the substrate, deposit a dynode material to form an initial dynode layer, and the initial dynode layer fills the A cavity array, and then tilting the substrate to remove part of the initial dynode layer to obtain a multiplication structure array, the multiplication structure array is arranged on the side wall of the cavity structure and is in electrical contact with the conductive structure.
28. The method according to claim 27, wherein the cavity array comprises several sub-cavity array layers, after S3, further comprising:

    S331: Fill the inside of the formed sub-cavity array layer with a sacrificial material, exposing the top surface of the formed sub-cavity array layer;

    S332: Use an interlayer material to form an interlayer isolation layer, the interlayer isolation layer covers the formed sub-cavity array layer, and includes several interlayer conductive structures and several interlayer via structures, each of the interlayer The through-hole structure is arranged relative to the acceleration cavity structure corresponding to the formed sub-cavity array layer, and at least part of the surface of the interlayer conductive structure is exposed; wherein,

    Repeat S3, S331, and S332 until several layers of sub-cavity array layers are formed, the interlayer isolation layer is provided between adjacent sub-cavity array layers, and at least one sub-cavity array layer is multiplied A structure electrically contacts the interlayer conductive structure.
29. The method according to claim 28, wherein the interlayer material further comprises a dispersion liquid, the dispersion liquid contains graphene oxide and an organic solvent, and after S332, the dispersion liquid is spin-coated on the acceleration chamber The opening of the structure, the graphene oxide layer covers at least one of the openings and is in contact with the interlayer conductive structure.
30. The method according to claim 29, characterized in that after removing the first/second sacrificial layer through the release via hole, part of the graphene oxide layer is removed.
31. The method according to claim 30, wherein removing part of the graphene oxide layer comprises forming channel holes in each of the graphene oxide layers by photolithography.
32. The method according to claim 31, characterized in that, after forming a channel hole in each graphene oxide layer by photolithography, reducing the remaining graphene oxide layer to obtain an accelerating electrode.
33. The method according to claim 26, characterized in that, after forming a second sacrificial layer, after the second sacrificial layer fills the space between adjacent multiplication structures and covers the top surfaces of the several multiplication structures, repeating S2 and S3 , until several layers of isolation layers are formed, several multiplication structures are formed in each layer of isolation layers, the conductive structures of adjacent isolation layers are arranged oppositely, and the sacrificial material fills the space between adjacent multiplication structures to form a complete sacrificial layer.
34. The method according to claim 26, characterized in that, in S3, removing part of the first sacrificial layer to form several inclined structures, including:

    The substrate is arranged obliquely, and then part of the first sacrificial layer is removed by etching to form several oblique structures.
35. The method according to claim 26, characterized in that before forming the first sacrificial layer, an auxiliary sacrificial material is deposited to form several auxiliary inclined structures; after forming the first sacrificial layer, the first sacrificial material on the same side as the auxiliary inclined structures is removed layer, removing the auxiliary sacrificial material to form several inclined structures.
36. The method according to claim 26, wherein the step of forming the top electrode comprises:

    Photolithography is performed using a grayscale mask to form a tapered structure that gradually thickens from the edge to the middle, and then a cathode material is deposited to form an initial top electrode on the top surface of the tapered structure.

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