CN105742386B - Photodiode and preparation method thereof, X-ray detection substrate and preparation method thereof - Google Patents

Abstract

The invention discloses a photodiode and its manufacturing method, an X-ray detection substrate and its manufacturing method. The photodiode comprises: a base substrate, and an intrinsic layer, a first doped layer and a second Doped layer; the orthographic projection of the upper surface of the intrinsic layer on the substrate is located in the area where the orthographic projection of the lower surface of the intrinsic layer is located on the substrate; the first doped layer and the second doped layer are respectively located On the two opposite inclined side surfaces of the intrinsic layer. In the above photodiode structure provided by the embodiment of the present invention, since the first doped layer and the second doped layer are respectively located on the two inclined side surfaces of the intrinsic layer, ion implantation can be used for doping in the manufacturing process , so that the doping concentration can be precisely controlled, and the performance of the photodiode can be effectively controlled, and the inclined side surface can increase the effective light-receiving area of the photodiode, collect more photogenerated carriers, and generate a higher signal intensity.

Description

Photodiode and manufacturing method thereof, X-ray detection substrate and manufacturing method thereof

technical field

The invention relates to the field of display technology, in particular to a photodiode and a manufacturing method thereof, an X-ray detection substrate and a manufacturing method thereof.

Background technique

X-ray inspection is widely used in medical, safety, non-destructive testing, scientific research and other fields, and it is increasingly playing an important role in the national economy and people's livelihood. At present, in actual use, X-ray detection generally uses film photography. The imaging quality of X-ray film photography is high, and it can correctly provide reliable information on the physical appearance and defects of the tested piece. However, it has the disadvantages of complicated operation process, high operating cost, difficult preservation of results, inconvenient query and portability, and easy access to the eyes of reviewers. Disadvantages such as damage by strong light. In order to solve the above problems, X-ray digital photography (DigitaI Radiography, DR) detection technology appeared in the late 1990s. The flat panel detector is used in the X-ray digital photography system, and its pixel size can be smaller than 0.1mm, so its imaging quality and resolution are almost comparable to those of film photography, and it also overcomes the limitations of film photography. It also provides convenience for computer processing of images. Due to the different electronic conversion modes, digital X-ray radiography detection can be divided into direct conversion type (Direct DR) and indirect conversion type (Indirect DR). The direct conversion type X-ray flat panel detector consists of a ray receiver, a command processor and a power supply. The ray receiver includes a scintillation crystal screen (Gd ₂ O ₂ S or CsI), a large-area amorphous silicon sensor array, and a readout circuit. Among them, the scintillation crystal screen is used to convert X-ray photons into visible light, and the large-scale integrated amorphous silicon sensor array close to it converts the visible light on the screen into electrons, which are then digitized by the readout circuit and sent to the computer to form Displayable digital images.

The indirect conversion detector is composed of an X-ray conversion layer, an amorphous silicon photodiode, a thin film transistor, a basic pixel unit for signal storage, and signal amplification and signal reading. The structure of the indirect flat panel detector is mainly composed of a scintillator (cesium iodide) or a phosphor (gadolinium oxysulfide) layer, an amorphous silicon layer with a photodiode function, and a TFT array. This type of flat panel detector scintillator or phosphor layer can convert X-rays into electrical signals after being exposed to X-rays, and read out the charge signal of each pixel through a thin-film transistor array and convert it into a digital signal and send it to the computer for image processing System integration for X-ray imaging.

The PIN photodiode is a key component of the indirect X-ray detection substrate, which determines the absorption efficiency of visible light, and has a great impact on key indicators such as X-ray dose, X-ray imaging resolution, and image response speed. The PIN preparation method of the indirect X-ray detection substrate mainly adopts PECVD technology, which can be conveniently processed at the same time through different process gases (such as: SiH ₄ , NH ₃ , N ₂ O, PH ₃ , H ₂ , B ₂ H ₆ , etc.) The PIN device can be quickly formed, but its disadvantage is that the doping concentration is relatively fixed, cannot be precisely controlled, and cannot achieve special regionalized doping.

Therefore, how to design a new PIN photodiode structure that can accurately control the doping concentration is a technical problem to be solved urgently by those skilled in the art.

Contents of the invention

In view of this, embodiments of the present invention provide a photodiode and its manufacturing method, an X-ray detection substrate and its manufacturing method, which can precisely control the doping concentration.

Therefore, an embodiment of the present invention provides a PIN photodiode, including: a base substrate, and an intrinsic layer, a first doped layer, and a second doped layer located on the base substrate;

The orthographic projection of the upper surface of the intrinsic layer on the base substrate is located in the area where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is located;

The first doped layer and the second doped layer are respectively located on two opposite inclined side surfaces of the intrinsic layer.

In a possible implementation manner, in the above-mentioned PIN photodiode provided by the embodiment of the present invention, the intrinsic layer has an isosceles trapezoidal structure in a cross section perpendicular to the base substrate.

In a possible implementation manner, the above PIN photodiode provided in the embodiment of the present invention further includes: a first transparent electrode layer located on the first doped layer;

and a second transparent electrode layer located on the second doped layer.

In a possible implementation manner, in the above PIN photodiode provided by the embodiment of the present invention, the first doped layer is a P-type semiconductor layer, and the second doped layer is an N-type semiconductor layer; or

The first doped layer is an N-type semiconductor layer, and the second doped layer is a P-type semiconductor layer.

An embodiment of the present invention also provides an X-ray detection substrate, including: a thin film transistor and a PIN photodiode; wherein,

The PIN photodiode is the above-mentioned PIN photodiode provided by the embodiment of the present invention.

In a possible implementation manner, in the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, the thin film transistor is a top-gate thin film transistor;

The drain of the top-gate thin film transistor is electrically connected to the first transparent electrode layer of the PIN photodiode.

In a possible implementation manner, the above-mentioned X-ray detection substrate provided in the embodiment of the present invention further includes:

a first protective layer over the PIN photodiode;

A cathode electrically connected to the second transparent electrode layer of the PIN photodiode through the via hole of the first protection layer.

In a possible implementation manner, in the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, the source and the drain of the top-gate thin film transistor are arranged in the same layer as the cathode.

In a possible implementation manner, the above-mentioned X-ray detection substrate provided in the embodiment of the present invention further includes:

A second protection layer located below the thin film transistor and the PIN photodiode and above the base substrate.

In a possible implementation manner, the above-mentioned X-ray detection substrate provided in the embodiment of the present invention further includes:

The resin encapsulation layer and the scintillation layer are stacked on the thin film transistor and the PIN photodiode.

The embodiment of the present invention also provides a method for manufacturing the above-mentioned PIN photodiode provided by the embodiment of the present invention, including:

Form the pattern of the intrinsic layer on the base substrate; the orthographic projection of the upper surface of the intrinsic layer on the base substrate is located where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is within the area;

forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process;

forming a pattern of a second doped layer on the other inclined side surface of the intrinsic layer opposite to the first doped layer formed by a patterning process and an ion implantation process;

Ion activation is performed on the first doped layer and the second doped layer through a high temperature activation process.

In a possible implementation manner, in the above-mentioned PIN photodiode manufacturing method provided by the embodiment of the present invention, after performing ion activation on the first doped layer and the second doped layer, further includes:

A pattern of the first transparent electrode layer is formed on the first doped layer, and a pattern of the second transparent electrode layer is formed on the second doped layer through a patterning process.

The embodiment of the present invention also provides a method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, including:

Form the pattern of the intrinsic layer on the base substrate; the orthographic projection of the upper surface of the intrinsic layer on the base substrate is located where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is within the area;

forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process;

forming a pattern of a second doped layer on the other inclined side surface of the intrinsic layer opposite to the first doped layer formed by a patterning process and an ion implantation process;

performing ion activation on the first doped layer and the second doped layer through a high temperature activation process;

A pattern of thin film transistors is formed on the base substrate.

In a possible implementation manner, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, after performing ion activation on the first doped layer and the second doped layer, after forming the thin film transistor Before graphics, also include:

A pattern of the first transparent electrode layer is formed on the first doped layer, and a pattern of the second transparent electrode layer is formed on the second doped layer through a patterning process.

In a possible implementation manner, in the manufacturing method of the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, after forming the pattern of the first transparent electrode layer and the second transparent electrode layer, it further includes:

A pattern of the first protection layer is formed on the base substrate.

In a possible implementation manner, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, forming a pattern of thin film transistors on the base substrate specifically includes:

forming a pattern of an active layer of a thin film transistor on the base substrate on which the pattern of the first protective layer is formed;

A source electrode, a drain electrode, and a cathode pattern electrically connected to the second transparent electrode layer through the via holes of the first protective layer are formed on the base substrate on which the active layer pattern is formed by a patterning process ;

A gate insulating layer and gate patterns are sequentially formed on the base substrate on which the source and drain patterns are formed.

In a possible implementation manner, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, before forming the pattern of the intrinsic layer on the substrate substrate, it further includes:

A pattern of the second protection layer is formed on the base substrate.

In a possible implementation manner, in the manufacturing method of the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, after forming the gate pattern, further includes:

Patterns of a resin encapsulation layer and a scintillation layer are sequentially formed on the base substrate.

The beneficial effects of the embodiments of the present invention include:

An embodiment of the present invention provides a photodiode and its manufacturing method, an X-ray detection substrate and its manufacturing method, the photodiode includes: a base substrate, and an intrinsic layer, a first doped layer and The second doped layer; the orthographic projection of the upper surface of the intrinsic layer on the substrate is located in the region where the orthographic projection of the lower surface of the intrinsic layer is on the substrate; the first doped layer and the second doped layer respectively located on two opposite inclined side surfaces of the intrinsic layer. In the above photodiode structure provided by the embodiment of the present invention, since the first doped layer and the second doped layer are respectively located on the two inclined side surfaces of the intrinsic layer, ion implantation can be used for doping in the manufacturing process , so that the doping concentration can be precisely controlled, and the performance of the photodiode can be effectively controlled, and the inclined side surface can increase the effective light-receiving area of the photodiode, collect more photogenerated carriers, and generate a higher signal intensity.

Description of drawings

Fig. 1 is one of the structural representations of the PIN photodiode provided by the embodiment of the present invention;

Fig. 2 is the second structural schematic diagram of the PIN photodiode provided by the embodiment of the present invention;

Fig. 3 is the flow chart of the manufacturing method of the PIN photodiode provided by the embodiment of the present invention;

Fig. 4 is one of the structural schematic diagrams of the X-ray detection substrate provided by the embodiment of the present invention;

Fig. 5 is the second structural schematic diagram of the X-ray detection substrate provided by the embodiment of the present invention;

Fig. 6 is one of the flow charts of the manufacturing method of the X-ray detection substrate provided by the embodiment of the present invention;

FIG. 7 is the second flow chart of the manufacturing method of the X-ray detection substrate provided by the embodiment of the present invention.

detailed description

Specific implementations of the photodiode and its manufacturing method, the X-ray detection substrate and its manufacturing method provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Wherein, the thickness and shape of each film layer in the drawings do not reflect the real ratio of the PIN photodiode and the X-ray detection substrate, and the purpose is only to illustrate the content of the present invention.

An embodiment of the present invention provides a PIN photodiode, as shown in FIG. 1 , including: a base substrate 10, and an intrinsic layer 11, a first doped layer 12, and a second doped layer located on the base substrate 10 13;

The orthographic projection of the upper surface of the intrinsic layer 11 on the base substrate 10 is located in the area where the orthographic projection of the lower surface of the intrinsic layer 11 on the base substrate 10 is located;

The first doped layer 12 and the second doped layer 13 are respectively located on two opposite inclined side surfaces of the intrinsic layer 11 .

In the above-mentioned PIN photodiode provided in the embodiment of the present invention, since the first doped layer and the second doped layer arranged in the PIN photodiode are respectively located on two opposite inclined side surfaces of the intrinsic layer, in the first The doping layer and the second doping layer can be doped by ion implantation in the manufacturing process, so that the doping concentration can be precisely controlled, and the performance of the photodiode can be effectively controlled, and the inclined side surface can increase The effective light-receiving area of the photodiode collects more photogenerated carriers and generates a higher signal intensity.

In specific implementation, in the above-mentioned PIN photodiode provided by the embodiment of the present invention, as shown in FIG. The size of the doped layer and the second doped layer are the same, thereby ensuring the performance of the photodiode. It should be noted that the thickness of the intrinsic layer can be set as to The thickness of the intrinsic layer may be determined according to actual conditions, and is not limited here.

Further, in specific implementation, in the above-mentioned PIN photodiode provided by the embodiment of the present invention, as shown in FIG. 2 , the PIN photodiode may further include: a first transparent electrode layer 14 located on the first doped layer 12 ; and the second transparent electrode layer 15 on the second doped layer 13 . That is to say, the transparent electrode layer arranged on the PIN photodiode is arranged in two parts, so that when applied to the X-ray detection substrate, one part can be electrically connected with the cathode, and the other part can be electrically connected with the drain in the thin film transistor , making the structure simpler. It should be noted that the material of the first transparent electrode layer and the second transparent electrode layer can be set to indium tin oxide (ITO), indium zinc oxide (IZO), graphene, nano-silver wire, zinc oxide (ZnO) among them One or a combination. The materials of the first transparent electrode layer and the second transparent electrode layer may be determined according to actual conditions, and are not limited here.

In specific implementation, in the above-mentioned PIN photodiode provided by the embodiment of the present invention, when the first doped layer can be set as a P-type semiconductor layer, then the second doped layer is an N-type semiconductor layer; or the first doped layer layer can be set as an N-type semiconductor layer, then the second doped layer is a P-type semiconductor layer. The types of the first doped layer and the second doped layer can be determined according to actual conditions, and are not limited here.

Based on the same inventive concept, the embodiment of the present invention also provides a manufacturing method of the above-mentioned PIN photodiode provided by the embodiment of the present invention. Since the principle of solving the problem of this method is similar to that of the aforementioned PIN photodiode, the implementation of the method can be See the implementation of the PIN photodiode, which will not be repeated here.

During specific implementation, the manufacturing method of the PIN photodiode provided by the embodiment of the present invention, as shown in Figure 3, specifically includes the following steps:

S301, forming the pattern of the intrinsic layer on the base substrate; the orthographic projection of the upper surface of the intrinsic layer on the base substrate is located in the area where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is located;

S302, forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process;

S303, forming a pattern of the second doped layer on the other inclined side surface of the intrinsic layer opposite to the formed first doped layer through a patterning process and an ion implantation process;

S304. Perform ion activation on the first doped layer and the second doped layer through a high temperature activation process.

In the manufacturing process of the above-mentioned PIN photodiode provided by the embodiment of the present invention, since ion implantation can be used to dope the first doped layer and the second doped layer located on the two inclined side surfaces of the intrinsic layer, thus The doping concentration can be precisely controlled to realize effective control of the performance of the photodiode. It should be noted that, when performing step S302, that is, in the process of forming the pattern of the first doped layer, the patterning process specifically refers to coating a layer of photoresist on the surface of the intrinsic layer, and through exposure and development processes, the to-be The photoresist in the area where the first doped layer pattern is formed is removed, then the ion implantation process is performed, and finally the photoresist is stripped; similarly, when step S303 is performed, that is, in the process of forming the second doped layer pattern Among them, the patterning process specifically refers to coating a layer of photoresist on the surface of the intrinsic layer, removing the photoresist in the area where the pattern of the second doped layer is to be formed through exposure and development processes, and then performing the ion implantation process , and finally the photoresist is stripped.

In specific implementation, in the above-mentioned PIN photodiode manufacturing method provided by the embodiment of the present invention, step S304 may further include: after performing ion activation on the first doped layer and the second doped layer:

A pattern of the first transparent electrode layer is formed on the first doped layer, and a pattern of the second transparent electrode layer is formed on the second doped layer through a patterning process.

The manufacturing method of the PIN photodiode provided by the embodiment of the present invention is described in detail below with a specific example, and the specific steps of making the PIN photodiode are as follows:

Step 1, forming the pattern of the intrinsic layer on the base substrate;

During specific implementation, a layer of α-Si:H thin film is deposited on the base substrate, and the thickness range of the α-Si:H thin film can be set at The patterning of the α-Si:H intrinsic layer is realized by coating, exposure, development, post-baking and etching, and the photoresist is peeled off; at this time, the upper surface of the formed α-Si:H intrinsic layer pattern is on the substrate The orthographic projection on the base substrate is located in the area where the orthographic projection of the lower surface of the α-Si:H intrinsic layer pattern on the base substrate is located;

Step 2, forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process;

In specific implementation, a layer of photoresist is coated on the intrinsic layer pattern formed after step 1, and the photoresist is exposed, developed, post-baked and etched to realize the first doping of P+α-Si:H Patterning of the impurity layer; then using an ion implantation process to realize the doping of the first doped layer of P+α-Si:H; finally stripping the photoresist on the intrinsic layer;

Step 3, forming a pattern of the second doped layer on the other inclined side surface of the intrinsic layer opposite to the formed first doped layer through a patterning process and an ion implantation process;

In specific implementation, a layer of photoresist is coated on the intrinsic layer pattern, and the photoresist is exposed, developed, post-baked and etched to realize the patterning of the N+α-Si:H second doped layer ; Afterwards, the ion implantation process is used to realize the doping of the N+α-Si:H second doped layer; finally, the photoresist on the intrinsic layer is stripped;

Step 4, performing ion activation on the first doped layer and the second doped layer through a high-temperature activation process;

In specific implementation, high-temperature activation processes, such as excimer laser annealing (ELA), rapid thermal annealing (RTA), high-temperature furnace heating (OVEN), etc., are used to inject ions into the first doped layer and the second doped layer. to activate;

Step 5, forming a pattern of the first transparent electrode layer on the first doped layer through a patterning process, and forming a pattern of the second transparent electrode layer on the second doped layer;

In specific implementation, after step 4 is performed, an electrode layer is deposited on the base substrate on which the first doped layer, the second doped layer, and the intrinsic layer pattern are formed, and the material of the electrode layer can be set as One or a combination of indium tin oxide (ITO), indium zinc oxide (IZO), graphene, nano-silver wire, zinc oxide (ZnO); conduct a patterning process on the electrode layer, that is, through coating, exposure, development, post-processing Baking and etching, forming the pattern of the first transparent electrode layer on the first doped layer, and forming the pattern of the second transparent electrode layer on the second doped layer.

So far, the above-mentioned PIN photodiode provided by the embodiment of the present invention has been produced through the above-mentioned steps 1 to 5 provided in the specific examples.

An embodiment of the present invention provides an X-ray detection substrate, as shown in FIG. 4 , including: a thin film transistor (TFT) and a PIN photodiode; wherein the PIN photodiode is a PIN photodiode in any of the above modes. The implementation of the X-ray detection substrate can refer to the above-mentioned embodiment of the PIN photodiode, and repeated descriptions will not be repeated.

The above-mentioned X-ray detection substrate provided in the embodiment of the present invention includes a thin film transistor and a PIN photodiode in any of the above-mentioned modes, and the orthographic projection of the upper surface of the intrinsic layer in the PIN photodiode on the base substrate is located at the intrinsic The lower surface of the layer is in the region where the orthographic projection on the substrate is located; the first doped layer and the second doped layer are respectively located on the two opposite inclined side surfaces of the intrinsic layer, so that the doping can be precisely controlled concentration, reduce the irradiation intensity of X-rays, realize effective control of photodiode performance, and set the inclined side surface to increase the effective light-receiving area of photodiode, collect more photogenerated carriers, and generate higher signal strength.

In specific implementation, in the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, as shown in FIG. 4 , the thin film transistor can be set as a top-gate thin film transistor; The first transparent electrode layer 14 of the X-ray detection substrate is electrically connected, such a structure can make the active layer 22 of the thin film transistor be protected by the grid 23 of the thin film transistor, and there will be no light shining on the active layer when the X-ray detection substrate is working, so as to avoid The effect of light on the performance of the active layer is eliminated, that is, effective light protection.

In specific implementation, in the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, as shown in FIG. A cathode 25 electrically connected to the second transparent electrode layer 15 of the PIN photodiode through a hole in the protection layer 24 . The first protective layer can avoid affecting the performance of the intrinsic layer of the PIN photodiode during the manufacturing process.

In specific implementation, in the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, as shown in FIG. , The drain and the cathode are arranged on the same layer, so that no additional preparation process is required when preparing the X-ray detection substrate, and the pattern of the source, drain and cathode can be formed by only one patterning process, which can save the preparation cost. Simplify the manufacturing process and improve production efficiency.

In specific implementation, in the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, in order to improve the contact performance between the thin film transistor and the PIN photodiode and the substrate substrate respectively, as shown in Figure 5, the X-ray detection substrate may also include : the second protection layer 27 located below the thin film transistor and the PIN photodiode and above the base substrate 10 .

In specific implementation, in the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, as shown in Fig. 4 and Fig. 5, the X-ray detection substrate may also include: a laminated layer located above the thin film transistor and the PIN photodiode resin encapsulation layer 28 and scintillation layer 29 .

Based on the same inventive concept, the embodiment of the present invention also provides a method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention. Since the problem-solving principle of this method is similar to that of the aforementioned X-ray detection substrate, the method’s For the implementation, please refer to the implementation of the X-ray detection substrate, and repeated descriptions will not be repeated.

In specific implementation, the manufacturing method of the X-ray detection substrate provided by the embodiment of the present invention, as shown in FIG. 6 , specifically includes the following steps:

S601, forming the pattern of the intrinsic layer on the base substrate; the orthographic projection of the upper surface of the intrinsic layer on the base substrate is located in the area where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is located;

S602, forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process;

S603, forming a pattern of the second doped layer on the other inclined side surface of the intrinsic layer opposite to the formed first doped layer through a patterning process and an ion implantation process;

S604, performing ion activation on the first doped layer and the second doped layer through a high temperature activation process;

S605, forming a pattern of thin film transistors on the base substrate.

In the manufacturing process of the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, since ion implantation can be used to dope the first doped layer and the second doped layer on the two inclined side surfaces of the intrinsic layer, In this way, the doping concentration can be precisely controlled, the irradiation intensity of X-rays can be reduced, and the performance of the photodiode can be effectively controlled. It should be noted that, after performing steps S601 to S604, performing step S605 to form the pattern of the thin film transistor can avoid the influence of the high temperature process on the performance of the thin film transistor, and realize the feasibility of applying the ion implantation process to the preparation of the X-ray detection substrate.

In specific implementation, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, after step S604 performs ion activation on the first doped layer and the second doped layer, step S605 forms the pattern of the thin film transistor Before, as shown in Figure 7, you can also include:

S606, forming a pattern of the first transparent electrode layer on the first doped layer through a patterning process, and forming a pattern of the second transparent electrode layer on the second doped layer.

In specific implementation, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, after forming the first transparent electrode layer and the second transparent electrode layer pattern, step S606 may further include:

S607, forming a pattern of the first protection layer on the base substrate.

In specific implementation, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, step S605 forms a pattern of a thin film transistor on the substrate substrate, as shown in FIG. 7 , which can be specifically implemented in the following manner:

S701, forming a pattern of an active layer of a thin film transistor on the base substrate on which the pattern of the first protective layer is formed;

S702, forming a pattern of a source electrode, a drain electrode, and a cathode electrically connected to the second transparent electrode layer through a via hole in the first protection layer on the base substrate on which the pattern of the active layer is formed through a patterning process;

S703, sequentially forming a gate insulating layer and a pattern of the gate on the base substrate on which the patterns of the source and the drain are formed.

In specific implementation, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, step S601 may further include:

S704, forming a pattern of the second protection layer on the base substrate.

In specific implementation, in the method for manufacturing the above-mentioned X-ray detection substrate provided by the embodiment of the present invention, after the gate pattern is formed in step S703, as shown in FIG. 7 , it may further include:

S705, sequentially forming patterns of a resin encapsulation layer and a scintillation layer on the base substrate.

The following uses a specific example to describe in detail the manufacturing method of the X-ray detection substrate provided by the embodiment of the present invention. The specific steps for manufacturing the X-ray detection substrate are as follows:

Step 1, forming a pattern of the second protective layer on the base substrate;

In specific implementation, a second protective layer film is deposited on the base substrate, and the material of the second protective layer film can be set as _Six O _y , _Six N _y , _Six O _y N _z , Al _x O One or a combination of _y , Ti _x O _y ; performing a patterning process on the second protective layer film, that is, forming a pattern of the second protective layer on the base substrate by applying glue, exposing, developing, post-baking and etching;

Step 2, forming the pattern of the intrinsic layer on the base substrate;

During specific implementation, a layer of α-Si:H thin film is deposited on the base substrate having the second protective layer pattern formed in Step 1, and the thickness range of the α-Si:H thin film can be set at The patterning of the α-Si:H intrinsic layer is realized by coating, exposure, development, post-baking and etching, and the photoresist is peeled off; at this time, the upper surface of the formed α-Si:H intrinsic layer pattern is on the substrate The orthographic projection on the base substrate is located in the area where the orthographic projection of the lower surface of the α-Si:H intrinsic layer pattern on the base substrate is located;

Step 3, forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process;

In specific implementation, a layer of photoresist is coated on the intrinsic layer pattern formed after step 2, and the photoresist is exposed, developed, post-baked and etched to realize the first doping of P+α-Si:H Patterning of the impurity layer; then using an ion implantation process to realize the doping of the first doped layer of P+α-Si:H; finally stripping the photoresist on the intrinsic layer;

Step 4, forming a pattern of the second doped layer on the other inclined side surface of the intrinsic layer opposite to the formed first doped layer through a patterning process and an ion implantation process;

In specific implementation, a layer of photoresist is coated on the intrinsic layer pattern, and the photoresist is exposed, developed, post-baked and etched to realize the patterning of the N+α-Si:H second doped layer ; Afterwards, the ion implantation process is used to realize the doping of the N+α-Si:H second doped layer; finally, the photoresist on the intrinsic layer is stripped;

Step 5, performing ion activation on the first doped layer and the second doped layer through a high-temperature activation process;

In specific implementation, high-temperature activation processes, such as excimer laser annealing (ELA), rapid thermal annealing (RTA), high-temperature furnace heating (OVEN), etc., are used to inject ions into the first doped layer and the second doped layer. to activate;

Step 6, forming a pattern of the first transparent electrode layer on the first doped layer through a patterning process, and forming a pattern of the second transparent electrode layer on the second doped layer;

In specific implementation, after step 5 is performed, an electrode layer is deposited on the base substrate on which the first doped layer, the second doped layer, and the intrinsic layer pattern are formed, and the material of the electrode layer can be set as One or a combination of indium tin oxide (ITO), indium zinc oxide (IZO), graphene, nano-silver wire, zinc oxide (ZnO); conduct a patterning process on the electrode layer, that is, through coating, exposure, development, post-processing Baking and etching, forming a pattern of the first transparent electrode layer on the first doped layer, and forming a pattern of the second transparent electrode layer on the second doped layer;

Step 7, forming a pattern of the first protective layer on the base substrate;

In specific implementation, after step 6 is performed, a first protective layer film is deposited on the base substrate on which the second protective layer, the first transparent electrode layer, the second transparent electrode layer, and the intrinsic layer pattern are formed, The material of the first protective layer film can be set as one or a combination of _{Six Oy} , _{Six Ny , Six Oy N z} , _AlxOy , _{TixOy ;} Patterning process, that is, forming the pattern of the first protective layer and the via hole of the first protective layer on the base substrate by applying glue, exposing, developing, post-baking and etching;

Step 8, forming the pattern of the active layer of the thin film transistor on the base substrate on which the pattern of the first protective layer is formed;

In specific implementation, after step 7 is performed, a layer of active layer film is deposited on the base substrate with the first protective layer pattern formed, and the material of the active layer film can be set to α-Si:H, LTPS One or a combination of , IGZO, ITZO, ZnON; patterning the active layer film, that is, forming the pattern of the active layer of the thin film transistor on the substrate by applying glue, exposing, developing, post-baking and etching ;

Step 9, forming a pattern of a source electrode, a drain electrode, and a cathode electrically connected to the second transparent electrode layer through a via hole in the first protective layer on the base substrate formed with an active layer pattern through a patterning process;

In specific implementation, after step 8 is performed, a source-drain metal layer is formed on the base substrate forming the active layer pattern, and the material of the source-drain metal layer can be set to Mo, Al, Ti, Cu , Nd, Nb, or a combination thereof; a patterning process is performed on the source and drain metal layers, that is, through coating, exposure, development, post-baking and etching, the source, drain, and pass through The pattern of the cathode electrically connected to the via hole of the first protective layer and the second transparent electrode layer;

Step 10, sequentially forming a gate insulating layer and gate patterns on the base substrate formed with source and drain patterns;

In specific implementation, a gate insulating layer film is deposited on the base substrate with source and drain patterns formed, and the material of the gate insulating layer film can be set as _Six O _y , _Six N _y , Si One or a combination of _x O _y N _z , Al _x O _y , Ti _x O _y ; the patterning process of the gate insulating layer film, that is, through coating, exposure, development, post-baking and etching, on the substrate Form the pattern of the gate insulating layer; then deposit a layer of gate metal layer on the gate insulating layer, the material of the gate metal layer can be set to one or a combination of Mo, Al, Ti, Cu, Nd, Nb ;Patterning the gate metal layer, that is, forming a gate pattern on the gate insulating layer by applying glue, exposing, developing, post-baking and etching;

Step eleven, sequentially forming patterns of the resin encapsulation layer and the scintillation layer on the base substrate;

In specific implementation, after step ten is performed, a layer of resin encapsulation layer film is coated on the base substrate, and the resin encapsulation layer film is patterned, that is, through glue coating, exposure, development, post-baking and etching, Form the pattern of the resin encapsulation layer on the base substrate; then evaporate a layer of scintillation layer on the resin encapsulation layer, the material of the scintillation layer can be set to one or a combination of Gd ₂ O ₂ S, CsI, HgI; finally encapsulation Complete the X-ray detection substrate preparation.

So far, the above-mentioned X-ray detection substrate provided by the embodiment of the present invention has been produced through the above-mentioned steps 1 to 11 provided in the specific examples.

An embodiment of the present invention provides a photodiode and its manufacturing method, an X-ray detection substrate and its manufacturing method, the photodiode includes: a base substrate, and an intrinsic layer, a first doped layer and The second doped layer; the orthographic projection of the upper surface of the intrinsic layer on the substrate is located in the region where the orthographic projection of the lower surface of the intrinsic layer is on the substrate; the first doped layer and the second doped layer respectively located on two opposite inclined side surfaces of the intrinsic layer. In the above photodiode structure provided by the embodiment of the present invention, since the first doped layer and the second doped layer are respectively located on the two inclined side surfaces of the intrinsic layer, ion implantation can be used for doping in the manufacturing process. , so that the doping concentration can be precisely controlled, and the performance of the photodiode can be effectively controlled, and the inclined side surface can increase the effective light-receiving area of the photodiode, collect more photogenerated carriers, and generate a higher signal intensity.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (17)

1. An X-ray detection substrate, characterized in that it comprises: a thin film transistor and a PIN photodiode; wherein, The PIN photodiode includes: a base substrate, and an intrinsic layer, a first doped layer, and a second doped layer located on the base substrate; The orthographic projection of the upper surface of the intrinsic layer on the base substrate is located in the area where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is located; The first doped layer and the second doped layer are respectively located on two opposite inclined side surfaces of the intrinsic layer; Wherein, the pattern of the first doped layer is formed on an inclined side surface of the intrinsic layer through a patterning process, an ion implantation process and a high temperature activation process; The pattern of the second doped layer is formed on the other inclined side surface of the intrinsic layer opposite to the first doped layer formed by patterning process, ion implantation process and high temperature activation process. 2 . The X-ray detection substrate according to claim 1 , wherein the intrinsic layer has an isosceles trapezoidal structure in a cross section perpendicular to the base substrate. 3 . 3. The X-ray detection substrate according to claim 1, further comprising: a first transparent electrode layer located on the first doped layer; and a second transparent electrode layer located on the second doped layer. 4. The X-ray detection substrate according to any one of claims 1-3, wherein the first doped layer is a P-type semiconductor layer, and the second doped layer is an N-type semiconductor layer; or The first doped layer is an N-type semiconductor layer, and the second doped layer is a P-type semiconductor layer. 5. The X-ray detection substrate according to claim 4, wherein the thin film transistor is a top-gate thin film transistor; The drain of the top-gate thin film transistor is electrically connected to the first transparent electrode layer of the PIN photodiode. 6. The X-ray detection substrate according to claim 5, further comprising: a first protective layer over the PIN photodiode; A cathode electrically connected to the second transparent electrode layer of the PIN photodiode through the via hole of the first protection layer. 7 . The X-ray detection substrate according to claim 6 , wherein the source and drain of the top-gate thin film transistor are arranged in the same layer as the cathode. 8. The X-ray detection substrate according to claim 1, further comprising: A second protection layer located below the thin film transistor and the PIN photodiode and above the base substrate. 9. The X-ray detection substrate according to claim 1, further comprising: The resin encapsulation layer and the scintillation layer are stacked on the thin film transistor and the PIN photodiode. 10. A method for making a PIN photodiode, comprising: Form the pattern of the intrinsic layer on the base substrate; the orthographic projection of the upper surface of the intrinsic layer on the base substrate is located where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is within the area; forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process; forming a pattern of a second doped layer on the other inclined side surface of the intrinsic layer opposite to the first doped layer formed by a patterning process and an ion implantation process; Ion activation is performed on the first doped layer and the second doped layer through a high temperature activation process. 11. The manufacturing method of PIN photodiode as claimed in claim 10, is characterized in that, after ion activation is carried out to described first doped layer and second doped layer, also comprises: A pattern of the first transparent electrode layer is formed on the first doped layer, and a pattern of the second transparent electrode layer is formed on the second doped layer through a patterning process. 12. A method for manufacturing the X-ray detection substrate according to any one of claims 1-9, characterized in that it comprises: Form the pattern of the intrinsic layer on the base substrate; the orthographic projection of the upper surface of the intrinsic layer on the base substrate is located where the orthographic projection of the lower surface of the intrinsic layer on the base substrate is within the area; forming a pattern of the first doped layer on an inclined side surface of the intrinsic layer through a patterning process and an ion implantation process; forming a pattern of a second doped layer on the other inclined side surface of the intrinsic layer opposite to the first doped layer formed by a patterning process and an ion implantation process; performing ion activation on the first doped layer and the second doped layer through a high temperature activation process; A pattern of thin film transistors is formed on the base substrate. 13. The manufacturing method of the X-ray detection substrate according to claim 12, characterized in that, after performing ion activation on the first doped layer and the second doped layer, before forming the pattern of the thin film transistor, further include: A pattern of the first transparent electrode layer is formed on the first doped layer, and a pattern of the second transparent electrode layer is formed on the second doped layer through a patterning process. 14. The method for manufacturing an X-ray detection substrate according to claim 13, further comprising: after forming the pattern of the first transparent electrode layer and the second transparent electrode layer: A pattern of the first protection layer is formed on the base substrate. 15. The method for manufacturing an X-ray detection substrate according to claim 14, wherein forming a pattern of a thin film transistor on the base substrate specifically comprises: forming a pattern of an active layer of a thin film transistor on the base substrate on which the pattern of the first protective layer is formed; A source electrode, a drain electrode, and a cathode pattern electrically connected to the second transparent electrode layer through the via hole of the first protective layer are formed on the base substrate formed with the pattern of the active layer through a patterning process ; A gate insulating layer and gate patterns are sequentially formed on the base substrate on which the source and drain patterns are formed. 16. The method for manufacturing an X-ray detection substrate according to claim 12, further comprising: before forming the pattern of the intrinsic layer on the base substrate: A pattern of the second protection layer is formed on the base substrate. 17. The method for manufacturing an X-ray detection substrate according to claim 15, further comprising: after forming the gate pattern: Patterns of a resin encapsulation layer and a scintillation layer are sequentially formed on the base substrate.