CN111370525A - Photodetector, preparation method thereof, and photodetector device - Google Patents

Abstract

The invention discloses a photodetector, a preparation method thereof and a photoelectric detection device. In the invention, a photosensitive semiconductor layer is directly formed on a base substrate, and an electrode layer is formed on the base substrate formed with the photosensitive semiconductor layer, namely the present invention. In the invention, the photosensitive device is first formed on the base substrate, and then the switching transistor is formed, which can improve the uniformity of each film layer in the photosensitive device, thereby improving the overall uniformity of the photodetector, thereby improving the performance of the photodetector; in addition, In the prior art, the switching transistor is formed first and then the photosensitive device is formed, so that the photosensitive semiconductor layer has an influence on the electrical characteristics of the metal oxide TFT; and the present invention forms the photosensitive semiconductor layer on the substrate first, which can reduce the photosensitive semiconductor layer. Influence on the electrical characteristics of the metal oxide TFT; in addition, the use of the structure of the present invention can also reduce the Mask process.

Description

Photodetector, preparation method thereof, and photodetector device

technical field

The invention relates to the technical field of photoelectric detection, in particular to a photoelectric detector, a preparation method thereof and a photoelectric detection device.

Background technique

Metal-Semiconductor-Metal (MSM) photodetectors utilize the Schottky barrier between the metal and semiconductor interface to form a carrier depletion region similar to a PN junction. Under the action of an external electric field, the photogenerated carriers generated by the incident light in the semiconductor drift motion in the depletion region of the reverse Schottky junction, and are quickly collected by the electrodes at both ends of the photodetector. MSM structured light detectors are widely used in various photon and particle detectors due to their simple structure, small parasitic capacitance, fast response speed, and low manufacturing cost.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a photodetector, a method for preparing the same, and a photodetector device, which are used to improve the overall uniformity of the photodetector, and at the same time, reduce the influence of the photosensitive semiconductor layer of the photodetector on the electrical characteristics of the metal oxide TFT, As well as reducing the Mask process.

An embodiment of the present invention provides a photodetector, comprising: a base substrate, a photosensitive semiconductor layer directly on the base substrate, and an electrode layer located on a side of the photosensitive semiconductor layer away from the base substrate.

Optionally, during specific implementation, the above-mentioned photodetector provided by the embodiment of the present invention further includes: a first passivation layer located on the side of the electrode layer away from the base substrate, and a first passivation layer located on the first passivation layer on the side of the electrode layer away from the base substrate. A switch transistor on the side of the passivation layer away from the base substrate; the material of the channel layer of the switch transistor is metal oxide, and the drain electrode of the switch transistor is electrically connected to the first electrode.

Optionally, during specific implementation, the above-mentioned photodetector provided in the embodiment of the present invention further includes: a second passivation layer located between the electrode layer and the first passivation layer, and a second passivation layer located between the electrode layer and the first passivation layer. a light shielding layer between the first passivation layer and the second passivation layer; the orthographic projection of the light shielding layer on the base substrate covers the channel layer of the switching transistor on the base substrate orthographic projection.

Correspondingly, an embodiment of the present invention also provides a photoelectric detection device, including the above-mentioned photodetector.

Correspondingly, an embodiment of the present invention also provides a method for preparing a photodetector, comprising:

forming a photosensitive semiconductor layer directly on the base substrate;

An electrode layer is formed on the base substrate on which the photosensitive semiconductor layer is formed; wherein, the electrode layer includes a first electrode and a second electrode which are insulated from each other and arranged at intervals.

Optionally, during specific implementation, in the above-mentioned preparation method provided by the embodiment of the present invention, after forming the photosensitive semiconductor layer and before forming the electrode layer, the method further includes: forming a potential barrier enhancement layer.

Optionally, during specific implementation, in the above-mentioned preparation method provided by the embodiment of the present invention, the forming the barrier enhancement layer specifically includes:

The barrier enhancement layer is formed at a temperature of 260°C-400°C by chemical vapor deposition.

Optionally, during specific implementation, in the above-mentioned preparation method provided in the embodiment of the present invention, after forming the photosensitive semiconductor layer and before forming the potential barrier enhancement layer, further comprising:

The photosensitive semiconductor layer is annealed at a temperature greater than 230°C.

Optionally, during specific implementation, in the above-mentioned preparation method provided in the embodiment of the present invention, it also includes:

forming a first passivation layer on the base substrate formed with the electrode layer;

A switching transistor is formed on the base substrate on which the first passivation layer is formed; the material of the channel layer of the switching transistor is metal oxide, and the drain of the switching transistor is electrically connected to the first electrode .

Optionally, during specific implementation, in the above-mentioned preparation method provided in the embodiment of the present invention, before forming the first passivation layer, the method further includes:

forming a second passivation layer on the base substrate formed with the conductive layer;

A light shielding layer is formed on the base substrate on which the second passivation layer is formed; the orthographic projection of the light shielding layer on the base substrate covers the projection of the channel layer of the switching transistor on the base substrate Orthographic projection.

The beneficial effects of the present invention are as follows:

In the photodetector, its preparation method, and the photodetector device provided by the embodiments of the present invention, the MSM type photodetector generally includes a photosensitive device and a switching transistor electrically connected to the photosensitive device. In the present invention, a photosensitive semiconductor layer is directly formed on a substrate. , and the electrode layer is formed on the base substrate formed with the photosensitive semiconductor layer, that is, the present invention adopts the photosensitive device to be formed on the base substrate first, and then the switching transistor is formed, which can improve the uniformity of each film layer in the photosensitive device, thereby Improve the overall uniformity of the photodetector, thereby improving the performance of the photodetector; in addition, in the prior art, the switching transistor is formed first and then the photosensitive device is formed. Since the material of the photosensitive semiconductor layer of the photosensitive device is a-Si, the existing Technology When depositing the a-Si layer, hydrogen ions will drift to the active layer of the metal oxide TFT, so that the active layer of the metal oxide TFT will produce donor defects, that is, the active layer of the metal oxide TFT has more defects. Electrons, so that the active layer of the metal oxide TFT is conductive in advance, causing the threshold voltage of the metal oxide TFT to shift, so the photosensitive semiconductor layer in the method of preparing the photodetector in the prior art has an effect on the electrical characteristics of the metal oxide TFT. In the present invention, the photosensitive semiconductor layer is first formed on the base substrate, so that the photosensitive semiconductor layer will not affect the active layer of the subsequently formed metal oxide TFT, thereby reducing the photosensitive semiconductor layer of the photodetector. The influence of the electrical characteristics of the oxide TFT; in addition, the use of the preparation method of the present invention can also reduce the Mask process.

Description of drawings

1 is a schematic structural diagram of a photodetector in the related art;

Fig. 2 is the volt-ampere characteristic curve measured under different source-drain voltages of the switching transistor for the structure shown in Fig. 1;

3 is one of the schematic flow charts of a method for preparing a photodetector according to an embodiment of the present invention;

FIG. 4 is a second schematic flowchart of a method for preparing a photodetector provided by an embodiment of the present invention;

FIG. 5 is a third schematic flowchart of a method for manufacturing a photodetector according to an embodiment of the present invention;

6 is a fourth schematic flowchart of a method for manufacturing a photodetector according to an embodiment of the present invention;

FIG. 7 is a fifth schematic flowchart of a method for manufacturing a photodetector provided by an embodiment of the present invention;

8 is a schematic cross-sectional structure diagram of a photodetector provided by an embodiment of the present invention;

FIG. 9 is a schematic top-view structural diagram of an electrode layer in a photodetector according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Also, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

Unless otherwise defined, technical or scientific terms used in the present invention should have the ordinary meaning as understood by one of ordinary skill in the art to which the present invention belongs. The terms "first," "second," and similar terms used herein do not denote any order, quantity, or importance, but are merely used to distinguish different components. "Comprises" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things. Words like "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

It should be noted that the dimensions and shapes of the figures in the accompanying drawings do not reflect the actual scale, and are only intended to illustrate the content of the present invention. And the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout.

At present, the MSM type photodetector in the related art, as shown in FIG. 1, includes a base substrate 01, a switching transistor 02 located on the base substrate (in order to improve the mobility, the switching transistor 02 is a metal oxide transistor), The first passivation layer 03 on the switching transistor 02, the first flat layer 04 on the first passivation layer 03, the buffer layer 05 on the first flat layer 04, the light shielding layer 06 on the buffer layer 05, The second flat layer 07 on the light shielding layer 06, the second passivation layer 08 on the second flat layer 07, the electrode layer 09 on the second passivation layer 08, the barrier enhancement layer on the electrode layer 09 10 , a photosensitive semiconductor layer 11 located on the barrier enhancement layer 10 , and a third passivation layer 12 located on the photosensitive semiconductor layer 11 . In the prior art, when the photodetector shown in FIG. 1 is fabricated, a switching transistor 02 is first fabricated on the base substrate 01, and then an electrode layer 09, a barrier enhancement layer 10 and a photosensitive semiconductor layer 11 are formed on the switching transistor 02. The formed photosensitive device, since the material of the photosensitive semiconductor layer 11 is a-Si, when depositing the a-Si layer in the prior art, the deposition materials include silane and hydrogen plasma, and during the deposition process, hydrogen ions will be directed to some parts of the switching transistor 02. The active layer of the switching transistor 02 drifts, so that the active layer of the switching transistor 02 has a donor defect, that is, the active layer of the switching transistor 02 has more electrons, so that the active layer of the switching transistor 02 is conductive in advance, resulting in a threshold value of the switching transistor 02. The voltage drifts, so the photosensitive semiconductor layer 11 has an impact on the electrical characteristics of the switching transistor 02 in the method of preparing the photodetector in the prior art, as shown in FIG. 2 , which takes the photodetector shown in FIG. 1 as an example The volt-ampere characteristic curve test, in which the abscissa represents the voltage V, and the ordinate represents the current I, respectively, when the source-drain voltage Vds of the switching transistor 02 is 0.1V, 5.1V, 10.1V and 15.1V, the test is carried out, using a constant current method, the intersection of the four curves corresponding to 0.1V, 5.1V, 10.1V and 15.1V when the current I=1.0E-9 is the threshold voltage Vth of the switching transistor 02, and the corresponding threshold voltage when Vds=0.1V can be obtained. Vth is -11.739. When Vds=5.1V, the corresponding threshold voltage Vth is -12.213. When Vds=10.1V, the corresponding threshold voltage Vth is -12.392. When Vds=15.1V, the corresponding threshold voltage Vth is -12.425. The threshold voltage Vth of 02 is generally close to 0, so the photosensitive semiconductor layer 11 in the method of manufacturing a photodetector in the prior art has an impact on the electrical characteristics of the switching transistor 02 . In addition, the electrode layer 09 in FIG. 1 generally includes interdigitated electrodes that are insulated from each other and are arranged independently, which causes the barrier enhancement layer 10 fabricated on the electrode layer 09 to be uneven. Since the thickness of the barrier enhancement layer 10 is relatively thin, the thickness It is difficult to control, resulting in poor uniformity of the photodetector, thus resulting in poor device performance; in addition, since the switching transistor 02 and the light shielding layer 06 in FIG. 1 need to be provided with a flat layer, the material of the flat layer is generally It is a resin material and is not resistant to high temperature, so the subsequent deposition of the barrier enhancement layer 10 and the photosensitive semiconductor layer 11 cannot be deposited at high temperature, the film quality is poor, and the barrier enhancement layer 10 has many internal defects, so the dark current of the photosensitive device is large. , resulting in a decrease in the contrast between photocurrent and dark current, which in turn leads to a decrease in sensitivity; and, when manufacturing the photodetector in Figure 1, a flat layer needs to be deposited twice, so the overall manufacturing process requires more Mask processes, and the manufacturing process flow more complicated.

In view of this, an embodiment of the present invention provides a method for preparing a photodetector, as shown in FIG. 3 , which may include:

S101, directly forming a photosensitive semiconductor layer on a base substrate;

S102 , forming an electrode layer on the base substrate on which the photosensitive semiconductor layer is formed; wherein, the electrode layer includes a first electrode and a second electrode that are insulated from each other and arranged at intervals.

In the preparation method of the above-mentioned photodetector provided by the embodiment of the present invention, the MSM type photodetector generally includes a photosensitive device and a switching transistor electrically connected to the photosensitive device. The electrode layer is formed on the base substrate with the photosensitive semiconductor layer, that is, the present invention adopts the method of forming the photosensitive device on the base substrate first, and then forming the switching transistor, which can improve the uniformity of each film layer in the photosensitive device, thereby improving the photodetector. In addition, in the prior art, the switching transistor is formed first and then the photosensitive device is formed. Since the material of the photosensitive semiconductor layer of the photosensitive device is a-Si, the prior art is in the deposition of a-Si. -Si layer, hydrogen ions will drift to the active layer of the metal oxide TFT, so that the active layer of the metal oxide TFT produces donor defects, that is, the active layer of the metal oxide TFT has more electrons, so that the The active layer of the metal oxide TFT is conductive in advance, resulting in a shift in the threshold voltage of the metal oxide TFT. Therefore, in the method for preparing a photodetector in the prior art, the photosensitive semiconductor layer has an impact on the electrical characteristics of the metal oxide TFT; The invention firstly forms a photosensitive semiconductor layer on the base substrate, so that the photosensitive semiconductor layer will not affect the active layer of the metal oxide TFT formed subsequently, so that the photosensitive semiconductor layer of the photodetector can reduce the electrical conductivity of the metal oxide TFT. In addition, using the preparation method of the present invention can also reduce the Mask process.

It should be noted that the photodetector provided by the embodiment of the present invention is an MSM type photodetector.

During specific implementation, in the above-mentioned preparation method provided by the embodiment of the present invention, as shown in FIG. 4 , after forming the photosensitive semiconductor layer and before forming the electrode layer, it further includes:

S102', forming a potential barrier enhancement layer; this is equivalent to increasing the thickness between the photosensitive semiconductor layer and the electrode layer of the MSM type photodetector, increasing the interface potential energy, thereby increasing the potential barrier, thus reducing the MSM type photodetector. Dark current to improve the sensitivity of MSM-type photodetectors.

During specific implementation, in the above-mentioned preparation method provided by the embodiment of the present invention, forming a potential barrier enhancement layer may specifically include:

The barrier enhancement layer is formed at a temperature of 260°C-400°C by chemical vapor deposition. Since the present invention forms each film layer of the photosensitive device first, and then forms the switching transistor (described later), there is no need to make a flat layer made of resin. On the one hand, the barrier enhancement layer can be deposited at high temperature, such as 260°C-400°C , the film quality of the barrier enhancement layer formed at this temperature is better, and the internal defects of the barrier enhancement layer are less, so the dark current of the photodetector can be further reduced, thereby further improving the sensitivity of the MSM photodetector; another On the one hand, the Mask for making the flat layer is reduced, thereby reducing the complexity of the production process.

During specific implementation, in the above-mentioned preparation method provided by the embodiment of the present invention, as shown in FIG. 5 , after forming the photosensitive semiconductor layer and before forming the barrier enhancement layer, the method further includes:

S101', annealing the photosensitive semiconductor layer at a temperature higher than 230°C. Since the present invention forms each film layer of the photosensitive device first, and then forms the switching transistor (described later), there is no need to make a flat layer made of resin. This can eliminate the residual hydrogen ions during deposition, thereby reducing dangling bonds, so the photosensitive semiconductor layer formed at this temperature has better film quality and fewer internal defects, so it can further reduce the dark current of the photodetector, In this way, the sensitivity of the MSM photodetector is further improved; on the other hand, the Mask for fabricating the flat layer is reduced, thereby reducing the complexity of the fabrication process.

During specific implementation, the above-mentioned preparation method provided by the embodiment of the present invention can at least reduce the Mask process of fabricating two flat layers compared with the structure shown in FIG. 1 in the related art.

During specific implementation, in the above-mentioned preparation method provided in the embodiment of the present invention, as shown in FIG. 6 , it also includes:

S103, forming a first passivation layer on the base substrate on which the electrode layer is formed;

Specifically, the first passivation layer is deposited at a high temperature of 150°C-400°C (preferably 370°C). The film quality of the first passivation layer deposited at this temperature is better, which can reduce the diffusion of hydrogen ions during the deposition of the photosensitive semiconductor layer. The probability of reaching the channel layer of the subsequently formed switching transistor will not affect the electrical characteristics of the switching transistor; specifically, the material of the first passivation layer can be SiO ₂ , and of course can also be other insulating materials.

S104, forming a switching transistor on the base substrate formed with the first passivation layer; in order to improve the mobility, the material of the channel layer of the switching transistor is a metal oxide, such as indium gallium zinc oxide (IGZO) and other metal oxides; And the drain of the switching transistor is electrically connected with the first electrode.

During specific implementation, in the above-mentioned preparation method provided by the embodiment of the present invention, as shown in FIG. 7 , before forming the first passivation layer, the method further includes:

S103', forming a second passivation layer on the base substrate formed with the conductive layer;

Specifically, the second passivation layer is deposited at a high temperature of 150° C. to 400° C. (preferably 370° C.). The film quality of the second passivation layer deposited at this temperature is better, which can further reduce hydrogen ions when depositing the photosensitive semiconductor layer. The probability of diffusing into the channel layer of the subsequently formed switching transistor will not further affect the electrical characteristics of the switching transistor; specifically, the material of the second passivation layer can also be SiO ₂ , and of course other insulating materials.

S103", forming a light-shielding layer on the base substrate formed with the second passivation layer; the orthographic projection of the light-shielding layer on the base substrate covers the orthographic projection of the channel layer of the switching transistor on the base substrate. The layer shields light to prevent incident light from irradiating on the channel layer of the switching transistor, thereby further improving the detection sensitivity.

To sum up, when the photodetector is fabricated by the aforementioned fabrication method provided in the embodiment of the present invention, the fabrication process conditions of each film layer are deposition at high temperature, reduction of Mask, etc., thus expanding the fabrication process window.

Based on the same inventive concept, an embodiment of the present invention also provides a photodetector prepared by using the above-mentioned preparation method for a photodetector, as shown in FIG. The photosensitive semiconductor layer 2 is the electrode layer 3 located on the side of the photosensitive semiconductor layer 2 away from the base substrate 1 ; the electrode layer 3 includes a first electrode 31 and a second electrode 32 which are insulated from each other and arranged at intervals.

In specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, as shown in FIG. 8 , light L is irradiated onto the photosensitive semiconductor layer 2 from the side of the photosensitive semiconductor layer 2 away from the base substrate 1 . Generally, the incident light enters the photosensitive semiconductor layer 2 to generate photo-generated carriers, and as the light continuously propagates to the depth in the photosensitive semiconductor layer 2 , the light intensity becomes weaker. Conventionally, in order to make the photosensitive semiconductor layer 2 fully absorb light, the film layer of the photosensitive semiconductor layer 2 needs to be made thicker, so that all light from the outside can be absorbed by the photosensitive semiconductor layer 2 . However, as the thickness of the photosensitive semiconductor layer 2 increases, the gradient of the photo-generated carrier concentration distribution in the photosensitive semiconductor layer 2 in the direction perpendicular to the photosensitive semiconductor layer 2 changes obviously, which is not conducive to light utilization. Therefore, in order to reduce the thickness of the photosensitive semiconductor layer 2, in the specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the materials of the first electrode 31 and the second electrode 32 can be opaque metal materials with high reflectivity, For example, metal materials such as Mo, Al, and Cu are used to deposit, and the thickness of the electrode layer 3 can be 50nm-1um, preferably 220nm.

During specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the material of the photosensitive semiconductor layer 2 may be a-Si. In order to increase the direct contact area between the photosensitive semiconductor layer 2 and light and increase the absorption of light by the photosensitive semiconductor layer 2, in the specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, as shown in FIG. 9, the first electrode 31 and the second electrode 32 form an interdigitated electrode.

In a specific implementation, the above-mentioned photodetector provided in the embodiment of the present invention, as shown in FIG. 8 , further includes: a first passivation layer 4 located on the side of the electrode layer 3 away from the base substrate 1 , and a first passivation layer 4 located on the side of the electrode layer 3 away from the base substrate 1 . The switch transistor 5 on the side of the passivation layer 4 away from the base substrate 1 ; the material of the channel layer 51 of the switch transistor 5 is metal oxide, and the drain 52 of the switch transistor 5 is electrically connected to the first electrode 31 .

Exemplarily, during specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, as shown in FIG. , the gate electrode 54 located above the gate insulating layer 53 , the source electrode 55 and the drain electrode 52 located above the gate electrode 54 and electrically connected to the channel layer 51 . The photodetector also includes an interlayer insulating layer 6 between the gate electrode 54 and the source and drain electrodes 55 and 52 . Of course, in practical applications, the structure of the switching transistor 5 may also adopt other structures, which are not limited herein.

During specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the material of the channel layer 51 may be IGZO, and the thickness may be 20 nm-100 nm, preferably 40 nm.

During specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the material of the gate insulating layer 53 may be SiO, and the thickness may be 50 nm-500 nm, preferably 150 nm.

During specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the gate electrode 54 may be deposited with metal materials such as Mo, Al, and Cu, and the thickness of the gate electrode 54 may be 50nm-1um, preferably 220nm.

During specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the material of the interlayer insulating layer 6 may be SiO, and the thickness may be 50nm-1um, preferably 450nm.

In specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the source electrode 55 and the drain electrode 52 may be deposited by using metal materials such as Mo, Al, and Cu, and the thickness of the source electrode 55 and the drain electrode 52 may be 50 nm- 1um, preferably 220nm.

During specific implementation, the above-mentioned photodetector provided in the embodiment of the present invention, as shown in FIG. 8 , further includes: a second passivation layer 7 located between the electrode layer 3 and the first passivation layer 4, and a second passivation layer 7 located between the electrode layer 3 and the first passivation layer 4 The light shielding layer 8 between the first passivation layer 4 and the second passivation layer 7; the orthographic projection of the light shielding layer 8 on the base substrate 1 covers the orthographic projection of the channel layer 51 of the switching transistor 5 on the base substrate 1 . In this way, light can be shielded by the light shielding layer 8 to prevent incident light from being irradiated on the channel layer 51 of the switching transistor 5, thereby further improving the detection sensitivity.

In specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the material of the first passivation layer 4 and the second passivation layer 7 can be SiO 2 , and the thickness can be 100nm-1um, preferably 300nm .

In addition, the first passivation layer 4 and the second passivation layer 7 may be deposited at a high temperature of 150°C-400°C (preferably 370°C), and the first passivation layer 4 and the second passivation layer 7 deposited at this temperature The quality of the film is better, which can further reduce the probability of hydrogen ions diffusing into the channel layer 51 of the switching transistor 5 formed later when the photosensitive semiconductor layer 2 is deposited, so that the electrical characteristics of the switching transistor 5 will not be affected.

In specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the light shielding layer 8 may be deposited by metal materials such as Mo, Al, and Cu, and the thickness of the light shielding layer 8 may be 50nm-1um, preferably 220nm.

During specific implementation, in order to prevent subsequent processes from affecting the source and drain of the switching transistor, in the above-mentioned photodetector provided in the embodiment of the present invention, as shown in FIG. The third passivation layer 9 can protect the source electrode 55 and the drain electrode 52 .

During specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the material of the third passivation layer 9 may be SiO 2 , and the thickness may be 50nm-1um, preferably 300nm.

In specific implementation, the above-mentioned photodetector provided in the embodiment of the present invention, as shown in FIG. 8 , further includes a scintillator 10 located on the base substrate 1 for photodetection, and the material of the scintillator 10 may be Gd ₂ O ₂ Materials such as S:Tb(GOS) or cesium iodide (CSI) can convert radiated light into visible light.

In specific implementation, in the above-mentioned photodetector provided by the embodiment of the present invention, the drain 52 passes through the via hole passing through the interlayer insulating layer 6 , the first passivation layer 4 and the second passivation layer 7 and the first electrode 31 electrical connection.

The preparation methods provided by the embodiments of the present invention will be described below through specific examples.

The preparation method provided in the embodiment of the present invention may include the following steps:

(1) A photosensitive semiconductor layer 2, a potential barrier enhancement layer 4, and an electrode layer 3 are sequentially formed on the base substrate 1. The electrode layer 3 includes a first electrode 31 and a second electrode 32 that are insulated from each other and arranged at intervals, as shown in FIG. 8 shown.

(2) The second passivation layer 7 , the light shielding layer 8 and the first passivation layer 4 are formed on the base substrate 1 on which the electrode layer 3 is formed, as shown in FIG. 8 .

(3) The switching transistor 5 is formed on the base substrate 1 on which the first passivation layer 4 is formed, and forming the switching transistor sequentially includes forming a channel layer 51 , a gate insulating layer 53 , a gate 54 , and forming an interlayer covering the gate 54 . The insulating layer 6 forms the source electrode 55 and the drain electrode 52, the source electrode 55 and the drain electrode 52 are electrically connected to the channel layer 51 through the via hole passing through the interlayer insulating layer 6, and the drain electrode 52 passes through the interlayer insulating layer 6, the first A via hole of the passivation layer 4 and the second passivation layer 7 is electrically connected to the first electrode 31 , as shown in FIG. 8 .

(4) The third passivation layer 9 is formed on the base substrate 1 on which the switching transistor 5 is formed, as shown in FIG. 8 .

(5) Incident light measurement by attaching the scintillator 10 to the base substrate 1 , as shown in FIG. 8 .

Based on the same inventive concept, an embodiment of the present invention further provides a photodetector device, including the above photodetector. The principle of solving the problem of the photoelectric detection device is similar to that of the foregoing photodetector, so the implementation of the photoelectric detection device may refer to the implementation of the foregoing photodetector, and the repetition will not be repeated here.

In the photodetector, its preparation method, and the photodetector device provided by the embodiments of the present invention, the MSM type photodetector generally includes a photosensitive device and a switching transistor electrically connected to the photosensitive device. In the present invention, a photosensitive semiconductor layer is directly formed on a substrate. , and the electrode layer is formed on the base substrate formed with the photosensitive semiconductor layer, that is, the present invention adopts the photosensitive device to be formed on the base substrate first, and then the switching transistor is formed, which can improve the uniformity of each film layer in the photosensitive device, thereby Improve the overall uniformity of the photodetector, thereby improving the performance of the photodetector; in addition, in the prior art, the switching transistor is formed first and then the photosensitive device is formed. Since the material of the photosensitive semiconductor layer of the photosensitive device is a-Si, the existing Technology When depositing the a-Si layer, hydrogen ions will drift to the active layer of the metal oxide TFT, so that the active layer of the metal oxide TFT will produce donor defects, that is, the active layer of the metal oxide TFT has more defects. Electrons, so that the active layer of the metal oxide TFT is conductive in advance, causing the threshold voltage of the metal oxide TFT to shift, so the photosensitive semiconductor layer in the method of preparing the photodetector in the prior art has an effect on the electrical characteristics of the metal oxide TFT. In the present invention, the photosensitive semiconductor layer is first formed on the base substrate, so that the photosensitive semiconductor layer will not affect the active layer of the subsequently formed metal oxide TFT, thereby reducing the photosensitive semiconductor layer of the photodetector. The influence of the electrical characteristics of the oxide TFT; in addition, the use of the preparation method of the present invention can also reduce the Mask process.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (10)

1. A photodetector, comprising: the semiconductor device comprises a substrate base plate, a photosensitive semiconductor layer directly positioned on the substrate base plate and an electrode layer positioned on one side of the photosensitive semiconductor layer, which is far away from the substrate base plate.

2. The photodetector of claim 1, further comprising: the first passivation layer is positioned on one side, away from the substrate, of the electrode layer, and the switch transistor is positioned on one side, away from the substrate, of the first passivation layer; the channel layer of the switching transistor is made of metal oxide, and the drain of the switching transistor is electrically connected with the first electrode.

3. The photodetector of claim 2, further comprising: a second passivation layer between the electrode layer and the first passivation layer, and a light shielding layer between the first passivation layer and the second passivation layer; the orthographic projection of the light shielding layer on the substrate covers the orthographic projection of the channel layer of the switching transistor on the substrate.

4. A photo detection device comprising a photo detector according to any of claims 1-3.

5. A method of fabricating a photodetector, comprising:

directly forming a photosensitive semiconductor layer on a substrate;

forming an electrode layer on the substrate with the photosensitive semiconductor layer formed thereon; the electrode layer comprises a first electrode and a second electrode which are insulated from each other and arranged at intervals.

6. The production method according to claim 5, further comprising, after forming the photosensitive semiconductor layer and before forming the electrode layer: a barrier enhancing layer is formed.

7. The method according to claim 6, wherein the forming the barrier enhancing layer specifically comprises:

and forming the barrier enhancement layer at a temperature of 260-400 ℃ by adopting a chemical vapor deposition method.

8. The production method according to claim 6, further comprising, after forming the photosensitive semiconductor layer and before forming the barrier enhancing layer:

and annealing the photosensitive semiconductor layer at a temperature of more than 230 ℃.

9. The method of any one of claims 5-8, further comprising:

forming a first passivation layer on the substrate with the electrode layer formed thereon;

forming a switching transistor on the substrate base plate on which the first passivation layer is formed; the channel layer of the switching transistor is made of metal oxide, and the drain of the switching transistor is electrically connected with the first electrode.

10. The method of manufacturing of claim 9, further comprising, prior to forming the first passivation layer:

forming a second passivation layer on the substrate on which the conductive layer is formed;

forming a light-shielding layer on the substrate on which the second passivation layer is formed; the orthographic projection of the light shielding layer on the substrate covers the orthographic projection of the channel layer of the switching transistor on the substrate.

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